From 771b69d270df888a28fd243926c43bda4239bccc Mon Sep 17 00:00:00 2001
From: Tristan Sloughter <t@crashfast.com>
Date: Wed, 13 Sep 2017 16:16:25 -0700
Subject: [PATCH 1/8] WIP: initial commit for Erlang client generator

---
 bin/erlang-petstore-client.sh                 |  31 ++
 .../languages/ErlangClientCodegen.java        | 359 ++++++++++++++++++
 .../services/io.swagger.codegen.CodegenConfig |   1 +
 .../resources/erlang-client/README.mustache   |   5 +
 .../main/resources/erlang-client/api.mustache |  25 ++
 .../resources/erlang-client/app.src.mustache  |  17 +
 .../resources/erlang-client/model.mustache    |   0
 .../erlang-client/rebar.config.mustache       |   3 +
 8 files changed, 441 insertions(+)
 create mode 100755 bin/erlang-petstore-client.sh
 create mode 100644 modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java
 create mode 100644 modules/swagger-codegen/src/main/resources/erlang-client/README.mustache
 create mode 100644 modules/swagger-codegen/src/main/resources/erlang-client/api.mustache
 create mode 100644 modules/swagger-codegen/src/main/resources/erlang-client/app.src.mustache
 create mode 100644 modules/swagger-codegen/src/main/resources/erlang-client/model.mustache
 create mode 100644 modules/swagger-codegen/src/main/resources/erlang-client/rebar.config.mustache

diff --git a/bin/erlang-petstore-client.sh b/bin/erlang-petstore-client.sh
new file mode 100755
index 00000000000..686ecd25629
--- /dev/null
+++ b/bin/erlang-petstore-client.sh
@@ -0,0 +1,31 @@
+#!/bin/sh
+
+SCRIPT="$0"
+
+while [ -h "$SCRIPT" ] ; do
+  ls=`ls -ld "$SCRIPT"`
+  link=`expr "$ls" : '.*-> \(.*\)$'`
+  if expr "$link" : '/.*' > /dev/null; then
+    SCRIPT="$link"
+  else
+    SCRIPT=`dirname "$SCRIPT"`/"$link"
+  fi
+done
+
+if [ ! -d "${APP_DIR}" ]; then
+  APP_DIR=`dirname "$SCRIPT"`/..
+  APP_DIR=`cd "${APP_DIR}"; pwd`
+fi
+
+executable="./modules/swagger-codegen-cli/target/swagger-codegen-cli.jar"
+
+if [ ! -f "$executable" ]
+then
+  mvn clean package
+fi
+
+# if you've executed sbt assembly previously it will use that instead.
+export JAVA_OPTS="${JAVA_OPTS} -XX:MaxPermSize=256M -Xmx1024M -DloggerPath=conf/log4j.properties"
+ags="$@ generate -t modules/swagger-codegen/src/main/resources/erlang-client -i modules/swagger-codegen/src/test/resources/2_0/petstore.yaml -l erlang-client -o samples/client/petstore/erlang-client"
+
+java $JAVA_OPTS -jar $executable $ags
diff --git a/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java
new file mode 100644
index 00000000000..3775961f4cf
--- /dev/null
+++ b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java
@@ -0,0 +1,359 @@
+package io.swagger.codegen.languages;
+
+import io.swagger.codegen.*;
+import com.samskivert.mustache.Mustache;
+import com.samskivert.mustache.Template;
+import io.swagger.models.properties.ArrayProperty;
+import io.swagger.models.properties.MapProperty;
+import io.swagger.models.properties.Property;
+import io.swagger.models.parameters.Parameter;
+
+import java.io.File;
+import java.util.*;
+import java.io.Writer;
+import java.io.IOException;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.apache.commons.lang3.StringUtils;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ErlangClientCodegen extends DefaultCodegen implements CodegenConfig {
+    static Logger LOGGER = LoggerFactory.getLogger(ErlangClientCodegen.class);
+
+    protected String packageName = "swagger";
+    protected String packageVersion = "1.0.0";
+    protected String sourceFolder = "src";
+
+    public CodegenType getTag() {
+        return CodegenType.CLIENT;
+    }
+
+    public String getName() {
+        return "erlang-client";
+    }
+
+    public String getHelp() {
+        return "Generates an Erlang client library (beta).";
+    }
+
+    public ErlangClientCodegen() {
+        super();
+        outputFolder = "generated-code/erlang";
+        //modelTemplateFiles.put("model.mustache", ".erl");
+        apiTemplateFiles.put("api.mustache", ".erl");
+
+        embeddedTemplateDir = templateDir = "erlang-client";
+
+        setReservedWordsLowerCase(
+                                  Arrays.asList(
+                                                "after","and","andalso","band","begin","bnot","bor","bsl","bsr","bxor","case",
+                                                "catch","cond","div","end","fun","if","let","not","of","or","orelse","receive",
+                                                "rem","try","when","xor"
+                                                )
+                                  );
+
+        instantiationTypes.clear();
+
+        typeMapping.clear();
+        typeMapping.put("enum", "binary");
+        typeMapping.put("date", "date");
+        typeMapping.put("datetime", "datetime");
+        typeMapping.put("boolean", "boolean");
+        typeMapping.put("string", "binary");
+        typeMapping.put("integer", "integer");
+        typeMapping.put("int", "integer");
+        typeMapping.put("float", "integer");
+        typeMapping.put("long", "integer");
+        typeMapping.put("double", "float");
+        typeMapping.put("array", "list");
+        typeMapping.put("map", "map");
+        typeMapping.put("number", "integer");
+        typeMapping.put("bigdecimal", "float");
+        typeMapping.put("List", "list");
+        typeMapping.put("object", "object");
+        typeMapping.put("file", "file");
+        typeMapping.put("binary", "binary");
+        typeMapping.put("bytearray", "binary");
+        typeMapping.put("byte", "binary");
+        typeMapping.put("uuid", "binary");
+        typeMapping.put("password", "binary");
+
+        cliOptions.clear();
+        cliOptions.add(new CliOption(CodegenConstants.PACKAGE_NAME, "Erlang application name (convention: lowercase).")
+                       .defaultValue(this.packageName));
+        cliOptions.add(new CliOption(CodegenConstants.PACKAGE_NAME, "Erlang application version")
+                       .defaultValue(this.packageVersion));
+
+
+    }
+
+    @Override
+    public void processOpts() {
+        super.processOpts();
+
+        if (additionalProperties.containsKey(CodegenConstants.PACKAGE_NAME)) {
+            setPackageName((String) additionalProperties.get(CodegenConstants.PACKAGE_NAME));
+        }
+        else {
+            setPackageName("swagger");
+        }
+
+        if (additionalProperties.containsKey(CodegenConstants.PACKAGE_VERSION)) {
+            setPackageVersion((String) additionalProperties.get(CodegenConstants.PACKAGE_VERSION));
+        }
+        else {
+            setPackageVersion("1.0.0");
+        }
+
+        additionalProperties.put(CodegenConstants.PACKAGE_NAME, packageName);
+        additionalProperties.put(CodegenConstants.PACKAGE_VERSION, packageVersion);
+
+        additionalProperties.put("lowercase", new Mustache.Lambda() {
+            @Override
+            public void execute(Template.Fragment fragment, Writer writer) throws IOException {
+                writer.write(lowercase(fragment.execute()));
+            }
+        });
+
+        additionalProperties.put("length", new Mustache.Lambda() {
+            @Override
+            public void execute(Template.Fragment fragment, Writer writer) throws IOException {
+                writer.write(length(fragment.context()));
+            }
+        });
+
+        modelPackage = packageName;
+        apiPackage = packageName;
+
+        supportingFiles.add(new SupportingFile("rebar.config.mustache","", "rebar.config"));
+        supportingFiles.add(new SupportingFile("app.src.mustache", "", "src" + File.separator + this.packageName + ".app.src"));
+        supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
+    }
+
+    @Override
+    public String escapeReservedWord(String name)
+    {
+        // Can't start with an underscore, as our fields need to start with an
+        // UppercaseLetter so that Go treats them as public/visible.
+
+        // Options?
+        // - MyName
+        // - AName
+        // - TheName
+        // - XName
+        // - X_Name
+        // ... or maybe a suffix?
+        // - Name_ ... think this will work.
+        if(this.reservedWordsMappings().containsKey(name)) {
+            return this.reservedWordsMappings().get(name);
+        }
+        return camelize(name) + '_';
+    }
+
+    @Override
+    public String apiFileFolder() {
+        return outputFolder + File.separator + sourceFolder + File.separator;
+    }
+
+
+    @Override
+    public String toVarName(String name) {
+        // replace - with _ e.g. created-at => created_at
+        name = sanitizeName(name.replaceAll("-", "_"));
+
+        // if it's all uppper case, do nothing
+        if (name.matches("^[A-Z_]*$"))
+            return name;
+
+        // camelize (lower first character) the variable name
+        // pet_id => PetId
+        name = camelize(name);
+
+        // for reserved word or word starting with number, append _
+        if (isReservedWord(name))
+            name = escapeReservedWord(name);
+
+        // for reserved word or word starting with number, append _
+        if (name.matches("^\\d.*"))
+            name = "Var" + name;
+
+        return name;
+    }
+
+    @Override
+    public String toParamName(String name) {
+        return camelize(toVarName(name));
+    }
+
+    @Override
+    public String toModelName(String name) {
+        return this.packageName + "_" + underscore(name.replaceAll("-", "_"));
+    }
+
+    @Override
+    public String toApiName(String name) {
+        return this.packageName + "_" + underscore(name.replaceAll("-", "_"));
+    }
+
+    @Override
+    public String toModelFilename(String name) {
+        return this.packageName + "_" + underscore(name);
+    }
+
+    @Override
+    public String toApiFilename(String name) {
+        // replace - with _ e.g. created-at => created_at
+        name = name.replaceAll("-", "_"); // FIXME: a parameter should not be assigned. Also declare the methods parameters as 'final'.
+
+        // e.g. PetApi.erl => pet_api.erl
+        return this.packageName + "_" + underscore(name) + "_api";
+    }
+
+    @Override
+    public String toOperationId(String operationId) {
+        // method name cannot use reserved keyword, e.g. return
+        if (isReservedWord(operationId)) {
+            LOGGER.warn(operationId + " (reserved word) cannot be used as method name. Renamed to " + underscore(sanitizeName("call_" + operationId)));
+            operationId = "call_" + operationId;
+        }
+
+        return underscore(operationId);
+    }
+
+    @Override
+    public Map<String, Object> postProcessOperations(Map<String, Object> objs) {
+        Map<String, Object> operations = (Map<String, Object>) objs.get("operations");
+        List<CodegenOperation> os = (List<CodegenOperation>) operations.get("operation");
+        List<ExtendedCodegenOperation> newOs = new ArrayList<ExtendedCodegenOperation>();
+        Pattern pattern = Pattern.compile("(.*)\\{([^\\}]+)\\}(.*)");
+        for (CodegenOperation o : os) {
+            ArrayList<String> pathTemplateNames = new ArrayList<String>();
+            Matcher matcher = pattern.matcher(o.path);
+            StringBuffer buffer = new StringBuffer();
+            while (matcher.find()) {
+                String pathTemplateName = matcher.group(2);
+                matcher.appendReplacement(buffer, "$1" + "\", " + camelize(pathTemplateName) + ", \"" + "$3");
+                pathTemplateNames.add(pathTemplateName);
+            }
+            ExtendedCodegenOperation eco = new ExtendedCodegenOperation(o);
+            if (buffer.toString().isEmpty()) {
+                eco.setReplacedPathName(o.path);
+            } else {
+                eco.setReplacedPathName(buffer.toString());
+            }
+            eco.setPathTemplateNames(pathTemplateNames);
+            newOs.add(eco);
+        }
+        operations.put("operation", newOs);
+        return objs;
+    }
+
+    public void setPackageName(String packageName) {
+        this.packageName = packageName;
+    }
+
+    public void setPackageVersion(String packageVersion) {
+        this.packageVersion = packageVersion;
+    }
+
+    String lowercase(String word) {
+        return word.toLowerCase();
+    }
+
+    String length(Object o) {
+        return Integer.toString((((ExtendedCodegenOperation) o).allParams).size());
+    }
+
+    @Override
+    public String escapeQuotationMark(String input) {
+        // remove " to avoid code injection
+        return input.replace("\"", "");
+    }
+
+    @Override
+    public String escapeUnsafeCharacters(String input) {
+        return input.replace("*/", "*_/").replace("/*", "/_*");
+    }
+
+    class ExtendedCodegenOperation extends CodegenOperation {
+        private List<String> pathTemplateNames = new ArrayList<String>();
+        private String replacedPathName;
+
+        public ExtendedCodegenOperation(CodegenOperation o) {
+            super();
+
+            // Copy all fields of CodegenOperation
+            this.responseHeaders.addAll(o.responseHeaders);
+            this.hasAuthMethods = o.hasAuthMethods;
+            this.hasConsumes = o.hasConsumes;
+            this.hasProduces = o.hasProduces;
+            this.hasParams = o.hasParams;
+            this.hasOptionalParams = o.hasOptionalParams;
+            this.returnTypeIsPrimitive = o.returnTypeIsPrimitive;
+            this.returnSimpleType = o.returnSimpleType;
+            this.subresourceOperation = o.subresourceOperation;
+            this.isMapContainer = o.isMapContainer;
+            this.isListContainer = o.isListContainer;
+            this.isMultipart = o.isMultipart;
+            this.hasMore = o.hasMore;
+            this.isResponseBinary = o.isResponseBinary;
+            this.hasReference = o.hasReference;
+            this.isRestfulIndex = o.isRestfulIndex;
+            this.isRestfulShow = o.isRestfulShow;
+            this.isRestfulCreate = o.isRestfulCreate;
+            this.isRestfulUpdate = o.isRestfulUpdate;
+            this.isRestfulDestroy = o.isRestfulDestroy;
+            this.isRestful = o.isRestful;
+            this.path = o.path;
+            this.operationId = o.operationId;
+            this.returnType = o.returnType;
+            this.httpMethod = o.httpMethod;
+            this.returnBaseType = o.returnBaseType;
+            this.returnContainer = o.returnContainer;
+            this.summary = o.summary;
+            this.unescapedNotes = o.unescapedNotes;
+            this.notes = o.notes;
+            this.baseName = o.baseName;
+            this.defaultResponse = o.defaultResponse;
+            this.discriminator = o.discriminator;
+            this.consumes = o.consumes;
+            this.produces = o.produces;
+            this.bodyParam = o.bodyParam;
+            this.allParams = o.allParams;
+            this.bodyParams = o.bodyParams;
+            this.pathParams = o.pathParams;
+            this.queryParams = o.queryParams;
+            this.headerParams = o.headerParams;
+            this.formParams = o.formParams;
+            this.authMethods = o.authMethods;
+            this.tags = o.tags;
+            this.responses = o.responses;
+            this.imports = o.imports;
+            this.examples = o.examples;
+            this.externalDocs = o.externalDocs;
+            this.vendorExtensions = o.vendorExtensions;
+            this.nickname = o.nickname;
+            this.operationIdLowerCase = o.operationIdLowerCase;
+            this.operationIdCamelCase = o.operationIdCamelCase;
+        }
+
+        public List<String> getPathTemplateNames() {
+            return pathTemplateNames;
+        }
+
+        public void setPathTemplateNames(List<String> pathTemplateNames) {
+            this.pathTemplateNames = pathTemplateNames;
+        }
+
+        public String getReplacedPathName() {
+            return replacedPathName;
+        }
+
+        public void setReplacedPathName(String replacedPathName) {
+            this.replacedPathName = replacedPathName;
+        }
+    }
+}
diff --git a/modules/swagger-codegen/src/main/resources/META-INF/services/io.swagger.codegen.CodegenConfig b/modules/swagger-codegen/src/main/resources/META-INF/services/io.swagger.codegen.CodegenConfig
index c8438e09a30..ae148900400 100644
--- a/modules/swagger-codegen/src/main/resources/META-INF/services/io.swagger.codegen.CodegenConfig
+++ b/modules/swagger-codegen/src/main/resources/META-INF/services/io.swagger.codegen.CodegenConfig
@@ -13,6 +13,7 @@ io.swagger.codegen.languages.CsharpDotNet2ClientCodegen
 io.swagger.codegen.languages.DartClientCodegen
 io.swagger.codegen.languages.ElixirClientCodegen
 io.swagger.codegen.languages.EiffelClientCodegen
+io.swagger.codegen.languages.ErlangClientCodegen
 io.swagger.codegen.languages.ErlangServerCodegen
 io.swagger.codegen.languages.FinchServerCodegen
 io.swagger.codegen.languages.FlashClientCodegen
diff --git a/modules/swagger-codegen/src/main/resources/erlang-client/README.mustache b/modules/swagger-codegen/src/main/resources/erlang-client/README.mustache
new file mode 100644
index 00000000000..f3eab0b5528
--- /dev/null
+++ b/modules/swagger-codegen/src/main/resources/erlang-client/README.mustache
@@ -0,0 +1,5 @@
+# Swagger client server library for Erlang
+
+## Overview
+
+An Erlang client stub generated by [Swagger Codegen](https://github.com/swagger-api/swagger-codegen) given an OpenAPI/Swagger spec.
diff --git a/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache b/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache
new file mode 100644
index 00000000000..9aa1e4ac6af
--- /dev/null
+++ b/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache
@@ -0,0 +1,25 @@
+-module({{classname}}_api).
+
+-export([{{#operations}}{{#operation}}{{^-first}},
+         {{/-first}}{{operationId}}/{{#length}}{{allParams}}{{/length}}{{/operation}}{{/operations}}]).
+
+-define(BASE_URL, <<"{{{basePath}}}">>).
+
+{{#operations}}
+    {{#operation}}
+
+%% {{summary}}
+%% {{^notes.isEmpty}}
+%% {{notes}}
+%% {{/notes.isEmpty}}
+{{operationId}}({{#allParams}}{{^-first}}, {{/-first}}{{paramName}}{{/allParams}}) ->
+    Method = {{#lowercase}}{{httpMethod}}{{/lowercase}},
+    Path = ["{{{replacedPathName}}}"],
+    QS = [{{^queryParams.isEmpty}}{{#queryParams}}{{^-first}}, {{/-first}}{<<"{{baseName}}">>, {{paramName}}}{{/queryParams}}{{/queryParams.isEmpty}}],
+    Headers = [{{^headerParams.isEmpty}}{{#headerParams}}{{^-first}}, {{/-first}}{<<"{{baseName}}">>, {{paramName}}}{{/headerParams}}{{/headerParams.isEmpty}}],
+    Body1 = {{^formParams.isEmpty}}{form, [{{#formParams}}{{^-first}}, {{/-first}}{<<"{{baseName}}">>, {{paramName}}}{{/formParams}}]}{{/formParams.isEmpty}}{{#formParams.isEmpty}}{{#bodyParams.isEmpty}}[]{{/bodyParams.isEmpty}}{{^bodyParams.isEmpty}}{{#bodyParams}}{{paramName}}{{/bodyParams}}{{/bodyParams.isEmpty}}{{/formParams.isEmpty}},
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+    hackney:request(Method, Url, Headers, Body1, Opts).
+    {{/operation}}
+{{/operations}}
diff --git a/modules/swagger-codegen/src/main/resources/erlang-client/app.src.mustache b/modules/swagger-codegen/src/main/resources/erlang-client/app.src.mustache
new file mode 100644
index 00000000000..8cf0543467a
--- /dev/null
+++ b/modules/swagger-codegen/src/main/resources/erlang-client/app.src.mustache
@@ -0,0 +1,17 @@
+{application, {{packageName}},
+ [{description, {{#appDescription}}"{{appDescription}}"{{/appDescription}}{{^appDescription}}"Swagger client library"{{/appDescription}}},
+  {vsn, "{{apiVersion}}"},
+  {registered, []},
+  {applications,
+    [kernel,
+     stdlib,
+     ssl,
+     hackney
+    ]},
+  {env, []},
+  {modules, []},
+
+  {maintainers, []},
+  {licenses, [{{#licenseInfo}}"{{licenseInfo}}"{{/licenseInfo}}]},
+  {links, [{{#infoUrl}}"{{infoUrl}}"{{/infoUrl}}]}
+]}.
diff --git a/modules/swagger-codegen/src/main/resources/erlang-client/model.mustache b/modules/swagger-codegen/src/main/resources/erlang-client/model.mustache
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/modules/swagger-codegen/src/main/resources/erlang-client/rebar.config.mustache b/modules/swagger-codegen/src/main/resources/erlang-client/rebar.config.mustache
new file mode 100644
index 00000000000..abe84a1a9f3
--- /dev/null
+++ b/modules/swagger-codegen/src/main/resources/erlang-client/rebar.config.mustache
@@ -0,0 +1,3 @@
+{erl_opts, [debug_info, warnings_as_errors, warn_untyped_record]}.
+
+{deps, [jsx, hackney]}.

From c0c17bd65de4c0b78919b7e16f0d1a344adadee8 Mon Sep 17 00:00:00 2001
From: Tristan Sloughter <t@crashfast.com>
Date: Wed, 13 Sep 2017 18:37:48 -0700
Subject: [PATCH 2/8] add models types and function type specs

---
 .../languages/ErlangClientCodegen.java        | 69 +++++++++----------
 .../main/resources/erlang-client/api.mustache | 10 +--
 .../resources/erlang-client/model.mustache    | 12 ++++
 3 files changed, 51 insertions(+), 40 deletions(-)

diff --git a/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java
index 3775961f4cf..68ca55eca74 100644
--- a/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java
+++ b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java
@@ -42,7 +42,7 @@ public String getHelp() {
     public ErlangClientCodegen() {
         super();
         outputFolder = "generated-code/erlang";
-        //modelTemplateFiles.put("model.mustache", ".erl");
+        modelTemplateFiles.put("model.mustache", ".erl");
         apiTemplateFiles.put("api.mustache", ".erl");
 
         embeddedTemplateDir = templateDir = "erlang-client";
@@ -58,28 +58,29 @@ public ErlangClientCodegen() {
         instantiationTypes.clear();
 
         typeMapping.clear();
-        typeMapping.put("enum", "binary");
-        typeMapping.put("date", "date");
-        typeMapping.put("datetime", "datetime");
-        typeMapping.put("boolean", "boolean");
-        typeMapping.put("string", "binary");
-        typeMapping.put("integer", "integer");
-        typeMapping.put("int", "integer");
-        typeMapping.put("float", "integer");
-        typeMapping.put("long", "integer");
-        typeMapping.put("double", "float");
-        typeMapping.put("array", "list");
-        typeMapping.put("map", "map");
-        typeMapping.put("number", "integer");
-        typeMapping.put("bigdecimal", "float");
-        typeMapping.put("List", "list");
-        typeMapping.put("object", "object");
-        typeMapping.put("file", "file");
-        typeMapping.put("binary", "binary");
-        typeMapping.put("bytearray", "binary");
-        typeMapping.put("byte", "binary");
-        typeMapping.put("uuid", "binary");
-        typeMapping.put("password", "binary");
+        typeMapping.put("enum", "binary()");
+        typeMapping.put("date", "calendar:date()");
+        typeMapping.put("datetime", "calendar:datetime()");
+        typeMapping.put("date-time", "calendar:datetime()");
+        typeMapping.put("boolean", "boolean()");
+        typeMapping.put("string", "binary()");
+        typeMapping.put("integer", "integer()");
+        typeMapping.put("int", "integer()");
+        typeMapping.put("float", "integer()");
+        typeMapping.put("long", "integer()");
+        typeMapping.put("double", "float()");
+        typeMapping.put("array", "list()");
+        typeMapping.put("map", "map()");
+        typeMapping.put("number", "integer()");
+        typeMapping.put("bigdecimal", "float()");
+        typeMapping.put("List", "list()");
+        typeMapping.put("object", "binary()");
+        typeMapping.put("file", "binary()");
+        typeMapping.put("binary", "binary()");
+        typeMapping.put("bytearray", "binary()");
+        typeMapping.put("byte", "binary()");
+        typeMapping.put("uuid", "binary()");
+        typeMapping.put("password", "binary()");
 
         cliOptions.clear();
         cliOptions.add(new CliOption(CodegenConstants.PACKAGE_NAME, "Erlang application name (convention: lowercase).")
@@ -90,6 +91,11 @@ public ErlangClientCodegen() {
 
     }
 
+    @Override
+    public String getTypeDeclaration(String name) {
+        return name + ":" + name + "()";
+    }
+
     @Override
     public void processOpts() {
         super.processOpts();
@@ -158,28 +164,19 @@ public String apiFileFolder() {
         return outputFolder + File.separator + sourceFolder + File.separator;
     }
 
+    @Override
+    public String modelFileFolder() {
+        return outputFolder + File.separator + sourceFolder + File.separator;
+    }
 
     @Override
     public String toVarName(String name) {
         // replace - with _ e.g. created-at => created_at
         name = sanitizeName(name.replaceAll("-", "_"));
-
-        // if it's all uppper case, do nothing
-        if (name.matches("^[A-Z_]*$"))
-            return name;
-
-        // camelize (lower first character) the variable name
-        // pet_id => PetId
-        name = camelize(name);
-
         // for reserved word or word starting with number, append _
         if (isReservedWord(name))
             name = escapeReservedWord(name);
 
-        // for reserved word or word starting with number, append _
-        if (name.matches("^\\d.*"))
-            name = "Var" + name;
-
         return name;
     }
 
diff --git a/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache b/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache
index 9aa1e4ac6af..251833e4945 100644
--- a/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache
+++ b/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache
@@ -7,11 +7,11 @@
 
 {{#operations}}
     {{#operation}}
-
-%% {{summary}}
-%% {{^notes.isEmpty}}
+%% @doc {{summary}}
+{{^notes.isEmpty}}
 %% {{notes}}
-%% {{/notes.isEmpty}}
+{{/notes.isEmpty}}
+-spec {{operationId}}({{#allParams}}{{^-first}}, {{/-first}}{{dataType}}{{/allParams}}) -> ok.
 {{operationId}}({{#allParams}}{{^-first}}, {{/-first}}{{paramName}}{{/allParams}}) ->
     Method = {{#lowercase}}{{httpMethod}}{{/lowercase}},
     Path = ["{{{replacedPathName}}}"],
@@ -21,5 +21,7 @@
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
     hackney:request(Method, Url, Headers, Body1, Opts).
+
     {{/operation}}
+
 {{/operations}}
diff --git a/modules/swagger-codegen/src/main/resources/erlang-client/model.mustache b/modules/swagger-codegen/src/main/resources/erlang-client/model.mustache
index e69de29bb2d..3974814c812 100644
--- a/modules/swagger-codegen/src/main/resources/erlang-client/model.mustache
+++ b/modules/swagger-codegen/src/main/resources/erlang-client/model.mustache
@@ -0,0 +1,12 @@
+{{#models}}
+{{#model}}
+-module({{classname}}).
+
+-export_type([{{classname}}/0]).
+
+-type {{classname}}() ::
+    #{ {{#vars}}'{{name}}' => {{{datatype}}}{{#hasMore}},
+       {{/hasMore}}{{/vars}}
+     }.
+{{/model}}
+{{/models}}

From 876301f716eb2e9681bc3c4dd1d408340fb06e3c Mon Sep 17 00:00:00 2001
From: Tristan Sloughter <t@crashfast.com>
Date: Thu, 14 Sep 2017 12:41:21 -0700
Subject: [PATCH 3/8] fix type specs when models are the type and support QS
 lists

---
 .../languages/ErlangClientCodegen.java        | 45 ++++++++++++++++++-
 .../main/resources/erlang-client/api.mustache | 19 ++++++--
 2 files changed, 59 insertions(+), 5 deletions(-)

diff --git a/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java
index 68ca55eca74..ee1f328011b 100644
--- a/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java
+++ b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java
@@ -70,11 +70,11 @@ public ErlangClientCodegen() {
         typeMapping.put("long", "integer()");
         typeMapping.put("double", "float()");
         typeMapping.put("array", "list()");
-        typeMapping.put("map", "map()");
+        typeMapping.put("map", "maps:map()");
         typeMapping.put("number", "integer()");
         typeMapping.put("bigdecimal", "float()");
         typeMapping.put("List", "list()");
-        typeMapping.put("object", "binary()");
+        typeMapping.put("object", "maps:map()");
         typeMapping.put("file", "binary()");
         typeMapping.put("binary", "binary()");
         typeMapping.put("bytearray", "binary()");
@@ -96,6 +96,29 @@ public String getTypeDeclaration(String name) {
         return name + ":" + name + "()";
     }
 
+    @Override
+    public String getTypeDeclaration(Property p) {
+        String swaggerType = getSwaggerType(p);
+        if (typeMapping.containsKey(swaggerType)) {
+            return typeMapping.get(swaggerType);
+        }
+        return swaggerType;
+    }
+
+    @Override
+    public String getSwaggerType(Property p) {
+        String swaggerType = super.getSwaggerType(p);
+        String type = null;
+        if(typeMapping.containsKey(swaggerType)) {
+            type = typeMapping.get(swaggerType);
+            if(languageSpecificPrimitives.contains(type))
+                return (type);
+        }
+        else
+            type = getTypeDeclaration(toModelName(snakeCase(swaggerType)));
+        return type;
+    }
+
     @Override
     public void processOpts() {
         super.processOpts();
@@ -131,6 +154,13 @@ public void execute(Template.Fragment fragment, Writer writer) throws IOExceptio
             }
         });
 
+        additionalProperties.put("qsEncode", new Mustache.Lambda() {
+            @Override
+            public void execute(Template.Fragment fragment, Writer writer) throws IOException {
+                writer.write(qsEncode(fragment.context()));
+            }
+        });
+
         modelPackage = packageName;
         apiPackage = packageName;
 
@@ -139,6 +169,17 @@ public void execute(Template.Fragment fragment, Writer writer) throws IOExceptio
         supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
     }
 
+    public String qsEncode(Object o) {
+        String r = new String();
+        CodegenParameter q = (CodegenParameter) o;
+        if (q.isListContainer) {
+            r += "[{<<\"" + q.baseName + "\">>, X} || X <- " + q.paramName + "]";
+        } else {
+            r += "{<<\"" + q.baseName + "\">>, " + q.paramName + "}";
+        }
+        return r;
+    }
+
     @Override
     public String escapeReservedWord(String name)
     {
diff --git a/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache b/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache
index 251833e4945..2d7c63285e1 100644
--- a/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache
+++ b/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache
@@ -11,16 +11,29 @@
 {{^notes.isEmpty}}
 %% {{notes}}
 {{/notes.isEmpty}}
--spec {{operationId}}({{#allParams}}{{^-first}}, {{/-first}}{{dataType}}{{/allParams}}) -> ok.
+-spec {{operationId}}({{#allParams}}{{^-first}}, {{/-first}}{{dataType}}{{/allParams}}) -> {{#returnType}}{{returnBaseType}}{{/returnType}}{{^returnType}}ok{{/returnType}}.
 {{operationId}}({{#allParams}}{{^-first}}, {{/-first}}{{paramName}}{{/allParams}}) ->
     Method = {{#lowercase}}{{httpMethod}}{{/lowercase}},
     Path = ["{{{replacedPathName}}}"],
-    QS = [{{^queryParams.isEmpty}}{{#queryParams}}{{^-first}}, {{/-first}}{<<"{{baseName}}">>, {{paramName}}}{{/queryParams}}{{/queryParams.isEmpty}}],
+    QS = lists:flatten([{{^queryParams.isEmpty}}{{#queryParams}}{{^-first}}, {{/-first}}{{#qsEncode}}{{this}}{{/qsEncode}}{{/queryParams}}{{/queryParams.isEmpty}}]),
     Headers = [{{^headerParams.isEmpty}}{{#headerParams}}{{^-first}}, {{/-first}}{<<"{{baseName}}">>, {{paramName}}}{{/headerParams}}{{/headerParams.isEmpty}}],
     Body1 = {{^formParams.isEmpty}}{form, [{{#formParams}}{{^-first}}, {{/-first}}{<<"{{baseName}}">>, {{paramName}}}{{/formParams}}]}{{/formParams.isEmpty}}{{#formParams.isEmpty}}{{#bodyParams.isEmpty}}[]{{/bodyParams.isEmpty}}{{^bodyParams.isEmpty}}{{#bodyParams}}{{paramName}}{{/bodyParams}}{{/bodyParams.isEmpty}}{{/formParams.isEmpty}},
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
-    hackney:request(Method, Url, Headers, Body1, Opts).
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {{#responses}}
+        {ok, {{code}}, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            {{#hasProduces}}{{#produces}}
+              <<"{{{mediaType}}}", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]){{#hasMore}}; {{/hasMore}}{{/produces}}
+            {{/hasProduces}}
+            end{{^-last}}; {{/-last}}
+        {{/responses}}
+    end.
 
     {{/operation}}
 

From 52995fa6339ba4520d6638f2a313e7307fa17522 Mon Sep 17 00:00:00 2001
From: Tristan Sloughter <t@crashfast.com>
Date: Wed, 20 Sep 2017 10:51:31 -0700
Subject: [PATCH 4/8] make method lowercase in postprocessoperations

---
 .../codegen/languages/ErlangClientCodegen.java     | 14 +++-----------
 .../src/main/resources/erlang-client/api.mustache  |  2 +-
 2 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java
index ee1f328011b..71cd3bfa5f9 100644
--- a/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java
+++ b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java
@@ -140,13 +140,6 @@ public void processOpts() {
         additionalProperties.put(CodegenConstants.PACKAGE_NAME, packageName);
         additionalProperties.put(CodegenConstants.PACKAGE_VERSION, packageVersion);
 
-        additionalProperties.put("lowercase", new Mustache.Lambda() {
-            @Override
-            public void execute(Template.Fragment fragment, Writer writer) throws IOException {
-                writer.write(lowercase(fragment.execute()));
-            }
-        });
-
         additionalProperties.put("length", new Mustache.Lambda() {
             @Override
             public void execute(Template.Fragment fragment, Writer writer) throws IOException {
@@ -268,6 +261,9 @@ public Map<String, Object> postProcessOperations(Map<String, Object> objs) {
         List<ExtendedCodegenOperation> newOs = new ArrayList<ExtendedCodegenOperation>();
         Pattern pattern = Pattern.compile("(.*)\\{([^\\}]+)\\}(.*)");
         for (CodegenOperation o : os) {
+            // force http method to lower case
+            o.httpMethod = o.httpMethod.toLowerCase();
+
             ArrayList<String> pathTemplateNames = new ArrayList<String>();
             Matcher matcher = pattern.matcher(o.path);
             StringBuffer buffer = new StringBuffer();
@@ -297,10 +293,6 @@ public void setPackageVersion(String packageVersion) {
         this.packageVersion = packageVersion;
     }
 
-    String lowercase(String word) {
-        return word.toLowerCase();
-    }
-
     String length(Object o) {
         return Integer.toString((((ExtendedCodegenOperation) o).allParams).size());
     }
diff --git a/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache b/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache
index 2d7c63285e1..b1e361ba63f 100644
--- a/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache
+++ b/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache
@@ -13,7 +13,7 @@
 {{/notes.isEmpty}}
 -spec {{operationId}}({{#allParams}}{{^-first}}, {{/-first}}{{dataType}}{{/allParams}}) -> {{#returnType}}{{returnBaseType}}{{/returnType}}{{^returnType}}ok{{/returnType}}.
 {{operationId}}({{#allParams}}{{^-first}}, {{/-first}}{{paramName}}{{/allParams}}) ->
-    Method = {{#lowercase}}{{httpMethod}}{{/lowercase}},
+    Method = {{httpMethod}},
     Path = ["{{{replacedPathName}}}"],
     QS = lists:flatten([{{^queryParams.isEmpty}}{{#queryParams}}{{^-first}}, {{/-first}}{{#qsEncode}}{{this}}{{/qsEncode}}{{/queryParams}}{{/queryParams.isEmpty}}]),
     Headers = [{{^headerParams.isEmpty}}{{#headerParams}}{{^-first}}, {{/-first}}{<<"{{baseName}}">>, {{paramName}}}{{/headerParams}}{{/headerParams.isEmpty}}],

From d30c5308189aecee139fe76db4c263300ad60a28 Mon Sep 17 00:00:00 2001
From: Tristan Sloughter <t@crashfast.com>
Date: Thu, 28 Sep 2017 19:21:46 -0700
Subject: [PATCH 5/8] add model encode function

---
 .../codegen/languages/ErlangClientCodegen.java      |  4 ++++
 .../src/main/resources/erlang-client/api.mustache   |  3 ++-
 .../src/main/resources/erlang-client/model.mustache | 13 +++++++++++--
 3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java
index 71cd3bfa5f9..2ce23aa0ecf 100644
--- a/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java
+++ b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/ErlangClientCodegen.java
@@ -264,6 +264,10 @@ public Map<String, Object> postProcessOperations(Map<String, Object> objs) {
             // force http method to lower case
             o.httpMethod = o.httpMethod.toLowerCase();
 
+            if (o.isListContainer) {
+                o.returnType = "[" + o.returnBaseType + "]";
+            }
+
             ArrayList<String> pathTemplateNames = new ArrayList<String>();
             Matcher matcher = pattern.matcher(o.path);
             StringBuffer buffer = new StringBuffer();
diff --git a/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache b/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache
index b1e361ba63f..1e0df0fe39b 100644
--- a/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache
+++ b/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache
@@ -11,7 +11,7 @@
 {{^notes.isEmpty}}
 %% {{notes}}
 {{/notes.isEmpty}}
--spec {{operationId}}({{#allParams}}{{^-first}}, {{/-first}}{{dataType}}{{/allParams}}) -> {{#returnType}}{{returnBaseType}}{{/returnType}}{{^returnType}}ok{{/returnType}}.
+-spec {{operationId}}({{#allParams}}{{^-first}}, {{/-first}}{{dataType}}{{/allParams}}) -> {{#returnType}}{{returnType}}{{/returnType}}{{^returnType}}ok{{/returnType}}.
 {{operationId}}({{#allParams}}{{^-first}}, {{/-first}}{{paramName}}{{/allParams}}) ->
     Method = {{httpMethod}},
     Path = ["{{{replacedPathName}}}"],
@@ -29,6 +29,7 @@
             {{#hasProduces}}{{#produces}}
               <<"{{{mediaType}}}", _/binary>> ->
                   {ok, Body} = hackney:body(ClientRef),
+
                   jsx:decode(Body, [returns_maps, {labels, attempt_atom}]){{#hasMore}}; {{/hasMore}}{{/produces}}
             {{/hasProduces}}
             end{{^-last}}; {{/-last}}
diff --git a/modules/swagger-codegen/src/main/resources/erlang-client/model.mustache b/modules/swagger-codegen/src/main/resources/erlang-client/model.mustache
index 3974814c812..da0e8672ca0 100644
--- a/modules/swagger-codegen/src/main/resources/erlang-client/model.mustache
+++ b/modules/swagger-codegen/src/main/resources/erlang-client/model.mustache
@@ -2,11 +2,20 @@
 {{#model}}
 -module({{classname}}).
 
--export_type([{{classname}}/0]).
+-export_type([{{classname}}/0,
+              encode/1,
+              decode/1]).
 
 -type {{classname}}() ::
-    #{ {{#vars}}'{{name}}' => {{{datatype}}}{{#hasMore}},
+    #{ {{#vars}}'{{name}}' {{#required}}:={{/required}}{{^required}}=>{{/required}} {{{datatype}}}{{#hasMore}},
        {{/hasMore}}{{/vars}}
      }.
+
+encode(#{ {{#vars}}'{{name}}' := {{{nameInCamelCase}}}{{#hasMore}},
+          {{/hasMore}}{{/vars}}
+        }) ->
+    #{ {{#vars}}'{{baseName}}' => {{{nameInCamelCase}}}{{#hasMore}},
+       {{/hasMore}}{{/vars}}
+     }
 {{/model}}
 {{/models}}

From bfbe52ff87efbe3eb5fcbd80c43eea4a1cb49207 Mon Sep 17 00:00:00 2001
From: Tristan Sloughter <t@crashfast.com>
Date: Thu, 28 Sep 2017 19:23:29 -0700
Subject: [PATCH 6/8] add erlang client sample

---
 .../erlang-client/.swagger-codegen-ignore     |  23 ++
 .../erlang-client/.swagger-codegen/VERSION    |   1 +
 .../client/petstore/erlang-client/README.md   |   5 +
 .../petstore/erlang-client/rebar.config       |   3 +
 .../erlang-client/src/swagger.app.src         |  17 +
 .../src/swagger_api_response.erl              |  20 ++
 .../erlang-client/src/swagger_category.erl    |  17 +
 .../erlang-client/src/swagger_order.erl       |  29 ++
 .../erlang-client/src/swagger_pet.erl         |  29 ++
 .../erlang-client/src/swagger_pet_api.erl     | 301 ++++++++++++++++++
 .../erlang-client/src/swagger_store_api.erl   | 165 ++++++++++
 .../erlang-client/src/swagger_tag.erl         |  17 +
 .../erlang-client/src/swagger_user.erl        |  35 ++
 .../erlang-client/src/swagger_user_api.erl    | 293 +++++++++++++++++
 14 files changed, 955 insertions(+)
 create mode 100644 samples/client/petstore/erlang-client/.swagger-codegen-ignore
 create mode 100644 samples/client/petstore/erlang-client/.swagger-codegen/VERSION
 create mode 100644 samples/client/petstore/erlang-client/README.md
 create mode 100644 samples/client/petstore/erlang-client/rebar.config
 create mode 100644 samples/client/petstore/erlang-client/src/swagger.app.src
 create mode 100644 samples/client/petstore/erlang-client/src/swagger_api_response.erl
 create mode 100644 samples/client/petstore/erlang-client/src/swagger_category.erl
 create mode 100644 samples/client/petstore/erlang-client/src/swagger_order.erl
 create mode 100644 samples/client/petstore/erlang-client/src/swagger_pet.erl
 create mode 100644 samples/client/petstore/erlang-client/src/swagger_pet_api.erl
 create mode 100644 samples/client/petstore/erlang-client/src/swagger_store_api.erl
 create mode 100644 samples/client/petstore/erlang-client/src/swagger_tag.erl
 create mode 100644 samples/client/petstore/erlang-client/src/swagger_user.erl
 create mode 100644 samples/client/petstore/erlang-client/src/swagger_user_api.erl

diff --git a/samples/client/petstore/erlang-client/.swagger-codegen-ignore b/samples/client/petstore/erlang-client/.swagger-codegen-ignore
new file mode 100644
index 00000000000..c5fa491b4c5
--- /dev/null
+++ b/samples/client/petstore/erlang-client/.swagger-codegen-ignore
@@ -0,0 +1,23 @@
+# Swagger Codegen Ignore
+# Generated by swagger-codegen https://github.com/swagger-api/swagger-codegen
+
+# Use this file to prevent files from being overwritten by the generator.
+# The patterns follow closely to .gitignore or .dockerignore.
+
+# As an example, the C# client generator defines ApiClient.cs.
+# You can make changes and tell Swagger Codgen to ignore just this file by uncommenting the following line:
+#ApiClient.cs
+
+# You can match any string of characters against a directory, file or extension with a single asterisk (*):
+#foo/*/qux
+# The above matches foo/bar/qux and foo/baz/qux, but not foo/bar/baz/qux
+
+# You can recursively match patterns against a directory, file or extension with a double asterisk (**):
+#foo/**/qux
+# This matches foo/bar/qux, foo/baz/qux, and foo/bar/baz/qux
+
+# You can also negate patterns with an exclamation (!).
+# For example, you can ignore all files in a docs folder with the file extension .md:
+#docs/*.md
+# Then explicitly reverse the ignore rule for a single file:
+#!docs/README.md
diff --git a/samples/client/petstore/erlang-client/.swagger-codegen/VERSION b/samples/client/petstore/erlang-client/.swagger-codegen/VERSION
new file mode 100644
index 00000000000..f9f7450d135
--- /dev/null
+++ b/samples/client/petstore/erlang-client/.swagger-codegen/VERSION
@@ -0,0 +1 @@
+2.3.0-SNAPSHOT
\ No newline at end of file
diff --git a/samples/client/petstore/erlang-client/README.md b/samples/client/petstore/erlang-client/README.md
new file mode 100644
index 00000000000..f3eab0b5528
--- /dev/null
+++ b/samples/client/petstore/erlang-client/README.md
@@ -0,0 +1,5 @@
+# Swagger client server library for Erlang
+
+## Overview
+
+An Erlang client stub generated by [Swagger Codegen](https://github.com/swagger-api/swagger-codegen) given an OpenAPI/Swagger spec.
diff --git a/samples/client/petstore/erlang-client/rebar.config b/samples/client/petstore/erlang-client/rebar.config
new file mode 100644
index 00000000000..abe84a1a9f3
--- /dev/null
+++ b/samples/client/petstore/erlang-client/rebar.config
@@ -0,0 +1,3 @@
+{erl_opts, [debug_info, warnings_as_errors, warn_untyped_record]}.
+
+{deps, [jsx, hackney]}.
diff --git a/samples/client/petstore/erlang-client/src/swagger.app.src b/samples/client/petstore/erlang-client/src/swagger.app.src
new file mode 100644
index 00000000000..6547fbd34e8
--- /dev/null
+++ b/samples/client/petstore/erlang-client/src/swagger.app.src
@@ -0,0 +1,17 @@
+{application, swagger,
+ [{description, "This is a sample server Petstore server.  You can find out more about Swagger at [http://swagger.io](http://swagger.io) or on [irc.freenode.net, #swagger](http://swagger.io/irc/).  For this sample, you can use the api key &#x60;special-key&#x60; to test the authorization filters."},
+  {vsn, ""},
+  {registered, []},
+  {applications,
+    [kernel,
+     stdlib,
+     ssl,
+     hackney
+    ]},
+  {env, []},
+  {modules, []},
+
+  {maintainers, []},
+  {licenses, ["Apache 2.0"]},
+  {links, []}
+]}.
diff --git a/samples/client/petstore/erlang-client/src/swagger_api_response.erl b/samples/client/petstore/erlang-client/src/swagger_api_response.erl
new file mode 100644
index 00000000000..33826528dc4
--- /dev/null
+++ b/samples/client/petstore/erlang-client/src/swagger_api_response.erl
@@ -0,0 +1,20 @@
+-module(swagger_api_response).
+
+-export_type([swagger_api_response/0,
+              encode/1,
+              decode/1]).
+
+-type swagger_api_response() ::
+    #{ 'code' => integer(),
+       'type' => binary(),
+       'message' => binary()
+     }.
+
+encode(#{ 'code' := Code,
+          'type' := Type,
+          'message' := Message
+        }) ->
+    #{ 'code' => Code,
+       'type' => Type,
+       'message' => Message
+     }
diff --git a/samples/client/petstore/erlang-client/src/swagger_category.erl b/samples/client/petstore/erlang-client/src/swagger_category.erl
new file mode 100644
index 00000000000..0bd89b55087
--- /dev/null
+++ b/samples/client/petstore/erlang-client/src/swagger_category.erl
@@ -0,0 +1,17 @@
+-module(swagger_category).
+
+-export_type([swagger_category/0,
+              encode/1,
+              decode/1]).
+
+-type swagger_category() ::
+    #{ 'id' => integer(),
+       'name' => binary()
+     }.
+
+encode(#{ 'id' := Id,
+          'name' := Name
+        }) ->
+    #{ 'id' => Id,
+       'name' => Name
+     }
diff --git a/samples/client/petstore/erlang-client/src/swagger_order.erl b/samples/client/petstore/erlang-client/src/swagger_order.erl
new file mode 100644
index 00000000000..06a9a1a270a
--- /dev/null
+++ b/samples/client/petstore/erlang-client/src/swagger_order.erl
@@ -0,0 +1,29 @@
+-module(swagger_order).
+
+-export_type([swagger_order/0,
+              encode/1,
+              decode/1]).
+
+-type swagger_order() ::
+    #{ 'id' => integer(),
+       'petId' => integer(),
+       'quantity' => integer(),
+       'shipDate' => swagger_date_time:swagger_date_time(),
+       'status' => binary(),
+       'complete' => boolean()
+     }.
+
+encode(#{ 'id' := Id,
+          'petId' := PetId,
+          'quantity' := Quantity,
+          'shipDate' := ShipDate,
+          'status' := Status,
+          'complete' := Complete
+        }) ->
+    #{ 'id' => Id,
+       'petId' => PetId,
+       'quantity' => Quantity,
+       'shipDate' => ShipDate,
+       'status' => Status,
+       'complete' => Complete
+     }
diff --git a/samples/client/petstore/erlang-client/src/swagger_pet.erl b/samples/client/petstore/erlang-client/src/swagger_pet.erl
new file mode 100644
index 00000000000..c9484fa0fea
--- /dev/null
+++ b/samples/client/petstore/erlang-client/src/swagger_pet.erl
@@ -0,0 +1,29 @@
+-module(swagger_pet).
+
+-export_type([swagger_pet/0,
+              encode/1,
+              decode/1]).
+
+-type swagger_pet() ::
+    #{ 'id' => integer(),
+       'category' => swagger_category:swagger_category(),
+       'name' := binary(),
+       'photoUrls' := list(),
+       'tags' => list(),
+       'status' => binary()
+     }.
+
+encode(#{ 'id' := Id,
+          'category' := Category,
+          'name' := Name,
+          'photoUrls' := PhotoUrls,
+          'tags' := Tags,
+          'status' := Status
+        }) ->
+    #{ 'id' => Id,
+       'category' => Category,
+       'name' => Name,
+       'photoUrls' => PhotoUrls,
+       'tags' => Tags,
+       'status' => Status
+     }
diff --git a/samples/client/petstore/erlang-client/src/swagger_pet_api.erl b/samples/client/petstore/erlang-client/src/swagger_pet_api.erl
new file mode 100644
index 00000000000..82042b05fd2
--- /dev/null
+++ b/samples/client/petstore/erlang-client/src/swagger_pet_api.erl
@@ -0,0 +1,301 @@
+-module(swagger_pet_api).
+
+-export([add_pet/1,
+         delete_pet/2,
+         find_pets_by_status/1,
+         find_pets_by_tags/1,
+         get_pet_by_id/1,
+         update_pet/1,
+         update_pet_with_form/3,
+         upload_file/3]).
+
+-define(BASE_URL, <<"http://petstore.swagger.io/v2">>).
+
+%% @doc Add a new pet to the store
+-spec add_pet(swagger_pet:swagger_pet()) -> ok.
+add_pet(Body) ->
+    Method = post,
+    Path = ["/pet"],
+    QS = lists:flatten([]),
+    Headers = [],
+    Body1 = Body,
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 405, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+%% @doc Deletes a pet
+-spec delete_pet(integer(), binary()) -> ok.
+delete_pet(PetId, ApiKey) ->
+    Method = delete,
+    Path = ["/pet/", PetId, ""],
+    QS = lists:flatten([]),
+    Headers = [{<<"api_key">>, ApiKey}],
+    Body1 = [],
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 400, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+%% @doc Finds Pets by status
+%% Multiple status values can be provided with comma separated strings
+-spec find_pets_by_status(list()) -> [swagger_pet:swagger_pet()].
+find_pets_by_status(Status) ->
+    Method = get,
+    Path = ["/pet/findByStatus"],
+    QS = lists:flatten([[{<<"status">>, X} || X <- Status]]),
+    Headers = [],
+    Body1 = [],
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 200, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end; 
+        {ok, 400, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+%% @doc Finds Pets by tags
+%% Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing.
+-spec find_pets_by_tags(list()) -> [swagger_pet:swagger_pet()].
+find_pets_by_tags(Tags) ->
+    Method = get,
+    Path = ["/pet/findByTags"],
+    QS = lists:flatten([[{<<"tags">>, X} || X <- Tags]]),
+    Headers = [],
+    Body1 = [],
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 200, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end; 
+        {ok, 400, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+%% @doc Find pet by ID
+%% Returns a single pet
+-spec get_pet_by_id(integer()) -> swagger_pet:swagger_pet().
+get_pet_by_id(PetId) ->
+    Method = get,
+    Path = ["/pet/", PetId, ""],
+    QS = lists:flatten([]),
+    Headers = [],
+    Body1 = [],
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 200, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end; 
+        {ok, 400, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end; 
+        {ok, 404, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+%% @doc Update an existing pet
+-spec update_pet(swagger_pet:swagger_pet()) -> ok.
+update_pet(Body) ->
+    Method = put,
+    Path = ["/pet"],
+    QS = lists:flatten([]),
+    Headers = [],
+    Body1 = Body,
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 400, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end; 
+        {ok, 404, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end; 
+        {ok, 405, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+%% @doc Updates a pet in the store with form data
+-spec update_pet_with_form(integer(), binary(), binary()) -> ok.
+update_pet_with_form(PetId, Name, Status) ->
+    Method = post,
+    Path = ["/pet/", PetId, ""],
+    QS = lists:flatten([]),
+    Headers = [],
+    Body1 = {form, [{<<"name">>, Name}, {<<"status">>, Status}]},
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 405, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+%% @doc uploads an image
+-spec upload_file(integer(), binary(), binary()) -> swagger_api_response:swagger_api_response().
+upload_file(PetId, AdditionalMetadata, File) ->
+    Method = post,
+    Path = ["/pet/", PetId, "/uploadImage"],
+    QS = lists:flatten([]),
+    Headers = [],
+    Body1 = {form, [{<<"additionalMetadata">>, AdditionalMetadata}, {<<"file">>, File}]},
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 200, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+
diff --git a/samples/client/petstore/erlang-client/src/swagger_store_api.erl b/samples/client/petstore/erlang-client/src/swagger_store_api.erl
new file mode 100644
index 00000000000..deee0a29279
--- /dev/null
+++ b/samples/client/petstore/erlang-client/src/swagger_store_api.erl
@@ -0,0 +1,165 @@
+-module(swagger_store_api).
+
+-export([delete_order/1,
+         get_inventory/0,
+         get_order_by_id/1,
+         place_order/1]).
+
+-define(BASE_URL, <<"http://petstore.swagger.io/v2">>).
+
+%% @doc Delete purchase order by ID
+%% For valid response try integer IDs with value &lt; 1000. Anything above 1000 or nonintegers will generate API errors
+-spec delete_order(binary()) -> ok.
+delete_order(OrderId) ->
+    Method = delete,
+    Path = ["/store/order/", OrderId, ""],
+    QS = lists:flatten([]),
+    Headers = [],
+    Body1 = [],
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 400, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end; 
+        {ok, 404, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+%% @doc Returns pet inventories by status
+%% Returns a map of status codes to quantities
+-spec get_inventory() -> maps:map().
+get_inventory() ->
+    Method = get,
+    Path = ["/store/inventory"],
+    QS = lists:flatten([]),
+    Headers = [],
+    Body1 = [],
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 200, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+%% @doc Find purchase order by ID
+%% For valid response try integer IDs with value &lt;&#x3D; 5 or &gt; 10. Other values will generated exceptions
+-spec get_order_by_id(integer()) -> swagger_order:swagger_order().
+get_order_by_id(OrderId) ->
+    Method = get,
+    Path = ["/store/order/", OrderId, ""],
+    QS = lists:flatten([]),
+    Headers = [],
+    Body1 = [],
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 200, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end; 
+        {ok, 400, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end; 
+        {ok, 404, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+%% @doc Place an order for a pet
+-spec place_order(swagger_order:swagger_order()) -> swagger_order:swagger_order().
+place_order(Body) ->
+    Method = post,
+    Path = ["/store/order"],
+    QS = lists:flatten([]),
+    Headers = [],
+    Body1 = Body,
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 200, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end; 
+        {ok, 400, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+
diff --git a/samples/client/petstore/erlang-client/src/swagger_tag.erl b/samples/client/petstore/erlang-client/src/swagger_tag.erl
new file mode 100644
index 00000000000..5abdf9b959f
--- /dev/null
+++ b/samples/client/petstore/erlang-client/src/swagger_tag.erl
@@ -0,0 +1,17 @@
+-module(swagger_tag).
+
+-export_type([swagger_tag/0,
+              encode/1,
+              decode/1]).
+
+-type swagger_tag() ::
+    #{ 'id' => integer(),
+       'name' => binary()
+     }.
+
+encode(#{ 'id' := Id,
+          'name' := Name
+        }) ->
+    #{ 'id' => Id,
+       'name' => Name
+     }
diff --git a/samples/client/petstore/erlang-client/src/swagger_user.erl b/samples/client/petstore/erlang-client/src/swagger_user.erl
new file mode 100644
index 00000000000..8c82c40488e
--- /dev/null
+++ b/samples/client/petstore/erlang-client/src/swagger_user.erl
@@ -0,0 +1,35 @@
+-module(swagger_user).
+
+-export_type([swagger_user/0,
+              encode/1,
+              decode/1]).
+
+-type swagger_user() ::
+    #{ 'id' => integer(),
+       'username' => binary(),
+       'firstName' => binary(),
+       'lastName' => binary(),
+       'email' => binary(),
+       'password' => binary(),
+       'phone' => binary(),
+       'userStatus' => integer()
+     }.
+
+encode(#{ 'id' := Id,
+          'username' := Username,
+          'firstName' := FirstName,
+          'lastName' := LastName,
+          'email' := Email,
+          'password' := Password,
+          'phone' := Phone,
+          'userStatus' := UserStatus
+        }) ->
+    #{ 'id' => Id,
+       'username' => Username,
+       'firstName' => FirstName,
+       'lastName' => LastName,
+       'email' => Email,
+       'password' => Password,
+       'phone' => Phone,
+       'userStatus' => UserStatus
+     }
diff --git a/samples/client/petstore/erlang-client/src/swagger_user_api.erl b/samples/client/petstore/erlang-client/src/swagger_user_api.erl
new file mode 100644
index 00000000000..12770e465ed
--- /dev/null
+++ b/samples/client/petstore/erlang-client/src/swagger_user_api.erl
@@ -0,0 +1,293 @@
+-module(swagger_user_api).
+
+-export([create_user/1,
+         create_users_with_array_input/1,
+         create_users_with_list_input/1,
+         delete_user/1,
+         get_user_by_name/1,
+         login_user/2,
+         logout_user/0,
+         update_user/2]).
+
+-define(BASE_URL, <<"http://petstore.swagger.io/v2">>).
+
+%% @doc Create user
+%% This can only be done by the logged in user.
+-spec create_user(swagger_user:swagger_user()) -> ok.
+create_user(Body) ->
+    Method = post,
+    Path = ["/user"],
+    QS = lists:flatten([]),
+    Headers = [],
+    Body1 = Body,
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 0, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+%% @doc Creates list of users with given input array
+-spec create_users_with_array_input(list()) -> ok.
+create_users_with_array_input(Body) ->
+    Method = post,
+    Path = ["/user/createWithArray"],
+    QS = lists:flatten([]),
+    Headers = [],
+    Body1 = Body,
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 0, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+%% @doc Creates list of users with given input array
+-spec create_users_with_list_input(list()) -> ok.
+create_users_with_list_input(Body) ->
+    Method = post,
+    Path = ["/user/createWithList"],
+    QS = lists:flatten([]),
+    Headers = [],
+    Body1 = Body,
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 0, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+%% @doc Delete user
+%% This can only be done by the logged in user.
+-spec delete_user(binary()) -> ok.
+delete_user(Username) ->
+    Method = delete,
+    Path = ["/user/", Username, ""],
+    QS = lists:flatten([]),
+    Headers = [],
+    Body1 = [],
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 400, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end; 
+        {ok, 404, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+%% @doc Get user by user name
+-spec get_user_by_name(binary()) -> swagger_user:swagger_user().
+get_user_by_name(Username) ->
+    Method = get,
+    Path = ["/user/", Username, ""],
+    QS = lists:flatten([]),
+    Headers = [],
+    Body1 = [],
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 200, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end; 
+        {ok, 400, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end; 
+        {ok, 404, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+%% @doc Logs user into the system
+-spec login_user(binary(), binary()) -> binary().
+login_user(Username, Password) ->
+    Method = get,
+    Path = ["/user/login"],
+    QS = lists:flatten([{<<"username">>, Username}, {<<"password">>, Password}]),
+    Headers = [],
+    Body1 = [],
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 200, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end; 
+        {ok, 400, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+%% @doc Logs out current logged in user session
+-spec logout_user() -> ok.
+logout_user() ->
+    Method = get,
+    Path = ["/user/logout"],
+    QS = lists:flatten([]),
+    Headers = [],
+    Body1 = [],
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 0, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+%% @doc Updated user
+%% This can only be done by the logged in user.
+-spec update_user(binary(), swagger_user:swagger_user()) -> ok.
+update_user(Username, Body) ->
+    Method = put,
+    Path = ["/user/", Username, ""],
+    QS = lists:flatten([]),
+    Headers = [],
+    Body1 = Body,
+    Opts = [],
+    Url = hackney_url:make_url(?BASE_URL, Path, QS),
+
+
+    case hackney:request(Method, Url, Headers, Body1, Opts) of
+        {ok, 400, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end; 
+        {ok, 404, RespHeaders, ClientRef} ->
+            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
+            
+              <<"application/xml", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
+              <<"application/json", _/binary>> ->
+                  {ok, Body} = hackney:body(ClientRef),
+
+                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
+            end
+    end.
+
+

From 7904ec167ab6ebb0a6f1924fc124ea1f15e64198 Mon Sep 17 00:00:00 2001
From: Tristan Sloughter <t@crashfast.com>
Date: Thu, 28 Sep 2017 19:29:15 -0700
Subject: [PATCH 7/8] add windows client sample script

---
 bin/windows/erlang-petstore-client.bat | 10 ++++++++++
 1 file changed, 10 insertions(+)
 create mode 100755 bin/windows/erlang-petstore-client.bat

diff --git a/bin/windows/erlang-petstore-client.bat b/bin/windows/erlang-petstore-client.bat
new file mode 100755
index 00000000000..228c0c7ca46
--- /dev/null
+++ b/bin/windows/erlang-petstore-client.bat
@@ -0,0 +1,10 @@
+set executable=.\modules\swagger-codegen-cli\target\swagger-codegen-cli.jar
+
+If Not Exist %executable% (
+  mvn clean package
+)
+
+REM set JAVA_OPTS=%JAVA_OPTS% -Xmx1024M
+set ags=generate -t modules\swagger-codegen\src\main\resources\erlang-client -i modules\swagger-codegen\src\test\resources\2_0\petstore.yaml -l erlang-client -o samples\client\petstore\erlang-client
+
+java %JAVA_OPTS% -jar %executable% %ags%

From cd8fc56200d04708de39ec92cb08b071cd646eab Mon Sep 17 00:00:00 2001
From: Tristan Sloughter <t@crashfast.com>
Date: Wed, 18 Oct 2017 21:18:13 -0700
Subject: [PATCH 8/8] proper return type spec and handle return error messages

---
 .../main/resources/erlang-client/api.mustache |  29 ++-
 .../erlang-client/src/swagger_pet_api.erl     | 228 ++++--------------
 .../erlang-client/src/swagger_store_api.erl   | 125 ++--------
 .../erlang-client/src/swagger_user_api.erl    | 226 ++++-------------
 4 files changed, 137 insertions(+), 471 deletions(-)

diff --git a/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache b/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache
index 1e0df0fe39b..a14ee991912 100644
--- a/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache
+++ b/modules/swagger-codegen/src/main/resources/erlang-client/api.mustache
@@ -11,29 +11,36 @@
 {{^notes.isEmpty}}
 %% {{notes}}
 {{/notes.isEmpty}}
--spec {{operationId}}({{#allParams}}{{^-first}}, {{/-first}}{{dataType}}{{/allParams}}) -> {{#returnType}}{{returnType}}{{/returnType}}{{^returnType}}ok{{/returnType}}.
+-spec {{operationId}}({{#allParams}}{{^-first}}, {{/-first}}{{dataType}}{{/allParams}}) -> {{#returnType}}{ok, list(), {{returnType}}} | {error, string()}{{/returnType}}{{^returnType}}ok | {error, integer()}{{/returnType}}.
 {{operationId}}({{#allParams}}{{^-first}}, {{/-first}}{{paramName}}{{/allParams}}) ->
     Method = {{httpMethod}},
     Path = ["{{{replacedPathName}}}"],
-    QS = lists:flatten([{{^queryParams.isEmpty}}{{#queryParams}}{{^-first}}, {{/-first}}{{#qsEncode}}{{this}}{{/qsEncode}}{{/queryParams}}{{/queryParams.isEmpty}}]),
+    QS = {{#queryParams.isEmpty}}[]{{/queryParams.isEmpty}}{{^queryParams.isEmpty}}lists:flatten([{{#queryParams}}{{^-first}}, {{/-first}}{{#qsEncode}}{{this}}{{/qsEncode}}{{/queryParams}}]){{/queryParams.isEmpty}},
     Headers = [{{^headerParams.isEmpty}}{{#headerParams}}{{^-first}}, {{/-first}}{<<"{{baseName}}">>, {{paramName}}}{{/headerParams}}{{/headerParams.isEmpty}}],
     Body1 = {{^formParams.isEmpty}}{form, [{{#formParams}}{{^-first}}, {{/-first}}{<<"{{baseName}}">>, {{paramName}}}{{/formParams}}]}{{/formParams.isEmpty}}{{#formParams.isEmpty}}{{#bodyParams.isEmpty}}[]{{/bodyParams.isEmpty}}{{^bodyParams.isEmpty}}{{#bodyParams}}{{paramName}}{{/bodyParams}}{{/bodyParams.isEmpty}}{{/formParams.isEmpty}},
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
+{{#returnType}}
         {{#responses}}
+{{#isDefault}}
         {ok, {{code}}, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            {{#hasProduces}}{{#produces}}
-              <<"{{{mediaType}}}", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]){{#hasMore}}; {{/hasMore}}{{/produces}}
-            {{/hasProduces}}
-            end{{^-last}}; {{/-last}}
+            {ok, Body} = hackney:body(ClientRef),
+            {ok, RespHeaders, jsx:decode(Body, [returns_maps, {labels, attempt_atom}])}{{#hasMore}}; {{/hasMore}}
+{{/isDefault}}
+{{^isDefault}}
+        {ok, {{code}}, _RespHeaders, _ClientRef} ->
+            {error, "{{message}}"}{{#hasMore}}; {{/hasMore}}
+{{/isDefault}}
         {{/responses}}
+{{/returnType}}
+{{^returnType}}
+        {ok, 200, _RespHeaders, _ClientRef} ->
+             ok;
+        {ok, Status, _RespHeaders, _ClientRef} ->
+             {error, Status}
+{{/returnType}}
     end.
 
     {{/operation}}
diff --git a/samples/client/petstore/erlang-client/src/swagger_pet_api.erl b/samples/client/petstore/erlang-client/src/swagger_pet_api.erl
index 82042b05fd2..7eaef8fed81 100644
--- a/samples/client/petstore/erlang-client/src/swagger_pet_api.erl
+++ b/samples/client/petstore/erlang-client/src/swagger_pet_api.erl
@@ -12,62 +12,44 @@
 -define(BASE_URL, <<"http://petstore.swagger.io/v2">>).
 
 %% @doc Add a new pet to the store
--spec add_pet(swagger_pet:swagger_pet()) -> ok.
+-spec add_pet(swagger_pet:swagger_pet()) -> ok | {error, integer()}.
 add_pet(Body) ->
     Method = post,
     Path = ["/pet"],
-    QS = lists:flatten([]),
+    QS = [],
     Headers = [],
     Body1 = Body,
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
-        {ok, 405, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+        {ok, 200, _RespHeaders, _ClientRef} ->
+             ok;
+        {ok, Status, _RespHeaders, _ClientRef} ->
+             {error, Status}
     end.
 
 %% @doc Deletes a pet
--spec delete_pet(integer(), binary()) -> ok.
+-spec delete_pet(integer(), binary()) -> ok | {error, integer()}.
 delete_pet(PetId, ApiKey) ->
     Method = delete,
     Path = ["/pet/", PetId, ""],
-    QS = lists:flatten([]),
+    QS = [],
     Headers = [{<<"api_key">>, ApiKey}],
     Body1 = [],
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
-        {ok, 400, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+        {ok, 200, _RespHeaders, _ClientRef} ->
+             ok;
+        {ok, Status, _RespHeaders, _ClientRef} ->
+             {error, Status}
     end.
 
 %% @doc Finds Pets by status
 %% Multiple status values can be provided with comma separated strings
--spec find_pets_by_status(list()) -> [swagger_pet:swagger_pet()].
+-spec find_pets_by_status(list()) -> {ok, list(), [swagger_pet:swagger_pet()]} | {error, string()}.
 find_pets_by_status(Status) ->
     Method = get,
     Path = ["/pet/findByStatus"],
@@ -77,37 +59,17 @@ find_pets_by_status(Status) ->
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
         {ok, 200, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end; 
-        {ok, 400, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+            {ok, Body} = hackney:body(ClientRef),
+            {ok, RespHeaders, jsx:decode(Body, [returns_maps, {labels, attempt_atom}])}; 
+        {ok, 400, _RespHeaders, _ClientRef} ->
+            {error, "Invalid status value"}
     end.
 
 %% @doc Finds Pets by tags
 %% Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing.
--spec find_pets_by_tags(list()) -> [swagger_pet:swagger_pet()].
+-spec find_pets_by_tags(list()) -> {ok, list(), [swagger_pet:swagger_pet()]} | {error, string()}.
 find_pets_by_tags(Tags) ->
     Method = get,
     Path = ["/pet/findByTags"],
@@ -117,185 +79,87 @@ find_pets_by_tags(Tags) ->
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
         {ok, 200, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end; 
-        {ok, 400, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+            {ok, Body} = hackney:body(ClientRef),
+            {ok, RespHeaders, jsx:decode(Body, [returns_maps, {labels, attempt_atom}])}; 
+        {ok, 400, _RespHeaders, _ClientRef} ->
+            {error, "Invalid tag value"}
     end.
 
 %% @doc Find pet by ID
 %% Returns a single pet
--spec get_pet_by_id(integer()) -> swagger_pet:swagger_pet().
+-spec get_pet_by_id(integer()) -> {ok, list(), swagger_pet:swagger_pet()} | {error, string()}.
 get_pet_by_id(PetId) ->
     Method = get,
     Path = ["/pet/", PetId, ""],
-    QS = lists:flatten([]),
+    QS = [],
     Headers = [],
     Body1 = [],
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
         {ok, 200, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end; 
-        {ok, 400, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end; 
-        {ok, 404, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+            {ok, Body} = hackney:body(ClientRef),
+            {ok, RespHeaders, jsx:decode(Body, [returns_maps, {labels, attempt_atom}])}; 
+        {ok, 400, _RespHeaders, _ClientRef} ->
+            {error, "Invalid ID supplied"}; 
+        {ok, 404, _RespHeaders, _ClientRef} ->
+            {error, "Pet not found"}
     end.
 
 %% @doc Update an existing pet
--spec update_pet(swagger_pet:swagger_pet()) -> ok.
+-spec update_pet(swagger_pet:swagger_pet()) -> ok | {error, integer()}.
 update_pet(Body) ->
     Method = put,
     Path = ["/pet"],
-    QS = lists:flatten([]),
+    QS = [],
     Headers = [],
     Body1 = Body,
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
-        {ok, 400, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end; 
-        {ok, 404, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end; 
-        {ok, 405, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+        {ok, 200, _RespHeaders, _ClientRef} ->
+             ok;
+        {ok, Status, _RespHeaders, _ClientRef} ->
+             {error, Status}
     end.
 
 %% @doc Updates a pet in the store with form data
--spec update_pet_with_form(integer(), binary(), binary()) -> ok.
+-spec update_pet_with_form(integer(), binary(), binary()) -> ok | {error, integer()}.
 update_pet_with_form(PetId, Name, Status) ->
     Method = post,
     Path = ["/pet/", PetId, ""],
-    QS = lists:flatten([]),
+    QS = [],
     Headers = [],
     Body1 = {form, [{<<"name">>, Name}, {<<"status">>, Status}]},
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
-        {ok, 405, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+        {ok, 200, _RespHeaders, _ClientRef} ->
+             ok;
+        {ok, Status, _RespHeaders, _ClientRef} ->
+             {error, Status}
     end.
 
 %% @doc uploads an image
--spec upload_file(integer(), binary(), binary()) -> swagger_api_response:swagger_api_response().
+-spec upload_file(integer(), binary(), binary()) -> {ok, list(), swagger_api_response:swagger_api_response()} | {error, string()}.
 upload_file(PetId, AdditionalMetadata, File) ->
     Method = post,
     Path = ["/pet/", PetId, "/uploadImage"],
-    QS = lists:flatten([]),
+    QS = [],
     Headers = [],
     Body1 = {form, [{<<"additionalMetadata">>, AdditionalMetadata}, {<<"file">>, File}]},
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
         {ok, 200, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+            {ok, Body} = hackney:body(ClientRef),
+            {ok, RespHeaders, jsx:decode(Body, [returns_maps, {labels, attempt_atom}])}
     end.
 
 
diff --git a/samples/client/petstore/erlang-client/src/swagger_store_api.erl b/samples/client/petstore/erlang-client/src/swagger_store_api.erl
index deee0a29279..1061556f5f6 100644
--- a/samples/client/petstore/erlang-client/src/swagger_store_api.erl
+++ b/samples/client/petstore/erlang-client/src/swagger_store_api.erl
@@ -9,157 +9,80 @@
 
 %% @doc Delete purchase order by ID
 %% For valid response try integer IDs with value &lt; 1000. Anything above 1000 or nonintegers will generate API errors
--spec delete_order(binary()) -> ok.
+-spec delete_order(binary()) -> ok | {error, integer()}.
 delete_order(OrderId) ->
     Method = delete,
     Path = ["/store/order/", OrderId, ""],
-    QS = lists:flatten([]),
+    QS = [],
     Headers = [],
     Body1 = [],
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
-        {ok, 400, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end; 
-        {ok, 404, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+        {ok, 200, _RespHeaders, _ClientRef} ->
+             ok;
+        {ok, Status, _RespHeaders, _ClientRef} ->
+             {error, Status}
     end.
 
 %% @doc Returns pet inventories by status
 %% Returns a map of status codes to quantities
--spec get_inventory() -> maps:map().
+-spec get_inventory() -> {ok, list(), maps:map()} | {error, string()}.
 get_inventory() ->
     Method = get,
     Path = ["/store/inventory"],
-    QS = lists:flatten([]),
+    QS = [],
     Headers = [],
     Body1 = [],
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
         {ok, 200, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+            {ok, Body} = hackney:body(ClientRef),
+            {ok, RespHeaders, jsx:decode(Body, [returns_maps, {labels, attempt_atom}])}
     end.
 
 %% @doc Find purchase order by ID
 %% For valid response try integer IDs with value &lt;&#x3D; 5 or &gt; 10. Other values will generated exceptions
--spec get_order_by_id(integer()) -> swagger_order:swagger_order().
+-spec get_order_by_id(integer()) -> {ok, list(), swagger_order:swagger_order()} | {error, string()}.
 get_order_by_id(OrderId) ->
     Method = get,
     Path = ["/store/order/", OrderId, ""],
-    QS = lists:flatten([]),
+    QS = [],
     Headers = [],
     Body1 = [],
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
         {ok, 200, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end; 
-        {ok, 400, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end; 
-        {ok, 404, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+            {ok, Body} = hackney:body(ClientRef),
+            {ok, RespHeaders, jsx:decode(Body, [returns_maps, {labels, attempt_atom}])}; 
+        {ok, 400, _RespHeaders, _ClientRef} ->
+            {error, "Invalid ID supplied"}; 
+        {ok, 404, _RespHeaders, _ClientRef} ->
+            {error, "Order not found"}
     end.
 
 %% @doc Place an order for a pet
--spec place_order(swagger_order:swagger_order()) -> swagger_order:swagger_order().
+-spec place_order(swagger_order:swagger_order()) -> {ok, list(), swagger_order:swagger_order()} | {error, string()}.
 place_order(Body) ->
     Method = post,
     Path = ["/store/order"],
-    QS = lists:flatten([]),
+    QS = [],
     Headers = [],
     Body1 = Body,
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
         {ok, 200, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end; 
-        {ok, 400, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+            {ok, Body} = hackney:body(ClientRef),
+            {ok, RespHeaders, jsx:decode(Body, [returns_maps, {labels, attempt_atom}])}; 
+        {ok, 400, _RespHeaders, _ClientRef} ->
+            {error, "Invalid Order"}
     end.
 
 
diff --git a/samples/client/petstore/erlang-client/src/swagger_user_api.erl b/samples/client/petstore/erlang-client/src/swagger_user_api.erl
index 12770e465ed..fe2a84d78a8 100644
--- a/samples/client/petstore/erlang-client/src/swagger_user_api.erl
+++ b/samples/client/petstore/erlang-client/src/swagger_user_api.erl
@@ -13,179 +13,101 @@
 
 %% @doc Create user
 %% This can only be done by the logged in user.
--spec create_user(swagger_user:swagger_user()) -> ok.
+-spec create_user(swagger_user:swagger_user()) -> ok | {error, integer()}.
 create_user(Body) ->
     Method = post,
     Path = ["/user"],
-    QS = lists:flatten([]),
+    QS = [],
     Headers = [],
     Body1 = Body,
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
-        {ok, 0, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+        {ok, 200, _RespHeaders, _ClientRef} ->
+             ok;
+        {ok, Status, _RespHeaders, _ClientRef} ->
+             {error, Status}
     end.
 
 %% @doc Creates list of users with given input array
--spec create_users_with_array_input(list()) -> ok.
+-spec create_users_with_array_input(list()) -> ok | {error, integer()}.
 create_users_with_array_input(Body) ->
     Method = post,
     Path = ["/user/createWithArray"],
-    QS = lists:flatten([]),
+    QS = [],
     Headers = [],
     Body1 = Body,
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
-        {ok, 0, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+        {ok, 200, _RespHeaders, _ClientRef} ->
+             ok;
+        {ok, Status, _RespHeaders, _ClientRef} ->
+             {error, Status}
     end.
 
 %% @doc Creates list of users with given input array
--spec create_users_with_list_input(list()) -> ok.
+-spec create_users_with_list_input(list()) -> ok | {error, integer()}.
 create_users_with_list_input(Body) ->
     Method = post,
     Path = ["/user/createWithList"],
-    QS = lists:flatten([]),
+    QS = [],
     Headers = [],
     Body1 = Body,
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
-        {ok, 0, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+        {ok, 200, _RespHeaders, _ClientRef} ->
+             ok;
+        {ok, Status, _RespHeaders, _ClientRef} ->
+             {error, Status}
     end.
 
 %% @doc Delete user
 %% This can only be done by the logged in user.
--spec delete_user(binary()) -> ok.
+-spec delete_user(binary()) -> ok | {error, integer()}.
 delete_user(Username) ->
     Method = delete,
     Path = ["/user/", Username, ""],
-    QS = lists:flatten([]),
+    QS = [],
     Headers = [],
     Body1 = [],
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
-        {ok, 400, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end; 
-        {ok, 404, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+        {ok, 200, _RespHeaders, _ClientRef} ->
+             ok;
+        {ok, Status, _RespHeaders, _ClientRef} ->
+             {error, Status}
     end.
 
 %% @doc Get user by user name
--spec get_user_by_name(binary()) -> swagger_user:swagger_user().
+-spec get_user_by_name(binary()) -> {ok, list(), swagger_user:swagger_user()} | {error, string()}.
 get_user_by_name(Username) ->
     Method = get,
     Path = ["/user/", Username, ""],
-    QS = lists:flatten([]),
+    QS = [],
     Headers = [],
     Body1 = [],
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
         {ok, 200, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end; 
-        {ok, 400, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end; 
-        {ok, 404, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+            {ok, Body} = hackney:body(ClientRef),
+            {ok, RespHeaders, jsx:decode(Body, [returns_maps, {labels, attempt_atom}])}; 
+        {ok, 400, _RespHeaders, _ClientRef} ->
+            {error, "Invalid username supplied"}; 
+        {ok, 404, _RespHeaders, _ClientRef} ->
+            {error, "User not found"}
     end.
 
 %% @doc Logs user into the system
--spec login_user(binary(), binary()) -> binary().
+-spec login_user(binary(), binary()) -> {ok, list(), binary()} | {error, string()}.
 login_user(Username, Password) ->
     Method = get,
     Path = ["/user/login"],
@@ -195,99 +117,49 @@ login_user(Username, Password) ->
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
         {ok, 200, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end; 
-        {ok, 400, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+            {ok, Body} = hackney:body(ClientRef),
+            {ok, RespHeaders, jsx:decode(Body, [returns_maps, {labels, attempt_atom}])}; 
+        {ok, 400, _RespHeaders, _ClientRef} ->
+            {error, "Invalid username/password supplied"}
     end.
 
 %% @doc Logs out current logged in user session
--spec logout_user() -> ok.
+-spec logout_user() -> ok | {error, integer()}.
 logout_user() ->
     Method = get,
     Path = ["/user/logout"],
-    QS = lists:flatten([]),
+    QS = [],
     Headers = [],
     Body1 = [],
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
-        {ok, 0, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+        {ok, 200, _RespHeaders, _ClientRef} ->
+             ok;
+        {ok, Status, _RespHeaders, _ClientRef} ->
+             {error, Status}
     end.
 
 %% @doc Updated user
 %% This can only be done by the logged in user.
--spec update_user(binary(), swagger_user:swagger_user()) -> ok.
+-spec update_user(binary(), swagger_user:swagger_user()) -> ok | {error, integer()}.
 update_user(Username, Body) ->
     Method = put,
     Path = ["/user/", Username, ""],
-    QS = lists:flatten([]),
+    QS = [],
     Headers = [],
     Body1 = Body,
     Opts = [],
     Url = hackney_url:make_url(?BASE_URL, Path, QS),
 
-
     case hackney:request(Method, Url, Headers, Body1, Opts) of
-        {ok, 400, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end; 
-        {ok, 404, RespHeaders, ClientRef} ->
-            case lists:keyfind(<<"Content-Type">>, 1, RespHeaders) of
-            
-              <<"application/xml", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}]); 
-              <<"application/json", _/binary>> ->
-                  {ok, Body} = hackney:body(ClientRef),
-
-                  jsx:decode(Body, [returns_maps, {labels, attempt_atom}])
-            end
+        {ok, 200, _RespHeaders, _ClientRef} ->
+             ok;
+        {ok, Status, _RespHeaders, _ClientRef} ->
+             {error, Status}
     end.