Add Credo to Elixir test suite

Makefile

@@ -194,13 +194,19 @@ python-black-update: .venv/bin/black
 		. dev/run rel/overlay/bin/couchup test/javascript/run
 
 .PHONY: elixir
-elixir: elixir-check-formatted devclean
+elixir: elixir-check-formatted elixir-credo devclean
 	@dev/run -a adm:pass --no-eval test/elixir/run
 
 .PHONY: elixir-check-formatted
 elixir-check-formatted:
 	@cd test/elixir/ && mix format --check-formatted
 
+# Credo is a static code analysis tool for Elixir.
+# We use it in our tests
+.PHONY: elixir-credo
+elixir-credo:
+	@cd test/elixir/ && mix deps.get && mix credo
+
 .PHONY: javascript
 # target: javascript - Run JavaScript test suites or specific ones defined by suites option
 javascript: devclean

Makefile.win

@@ -165,13 +165,19 @@ python-black-update: .venv/bin/black
 		. dev\run rel\overlay\bin\couchup test\javascript\run
 
 .PHONY: elixir
-elixir: elixir-check-formatted devclean
+elixir: elixir-check-formatted elixir-credo devclean
 	@dev\run -a adm:pass --no-eval test\elixir\run.cmd
 
 .PHONY: elixir-check-formatted
 elixir-check-formatted:
 	@cd test\elixir && mix format --check-formatted
 
+# Credo is a static code analysis tool for Elixir.
+# We use it in our tests
+.PHONY: elixir-credo
+elixir-credo:
+	@cd test/elixir/ && mix deps.get && mix credo
+
 .PHONY: test-cluster-with-quorum
 test-cluster-with-quorum: devclean
 	-@mkdir share\www\script\test

test/elixir/.credo.exs

@@ -0,0 +1,153 @@
+# This file contains the configuration for Credo and you are probably reading
+# this after creating it with `mix credo.gen.config`.
+#
+# If you find anything wrong or unclear in this file, please report an
+# issue on GitHub: https://github.com/rrrene/credo/issues
+#
+%{
+  #
+  # You can have as many configs as you like in the `configs:` field.
+  configs: [
+    %{
+      #
+      # Run any exec using `mix credo -C <name>`. If no exec name is given
+      # "default" is used.
+      #
+      name: "default",
+      #
+      # These are the files included in the analysis:
+      files: %{
+        #
+        # You can give explicit globs or simply directories.
+        # In the latter case `**/*.{ex,exs}` will be used.
+        #
+        included: ["lib/", "src/", "test/", "web/", "apps/"],
+        excluded: [~r"/_build/", ~r"/deps/", ~r"/node_modules/"]
+      },
+      #
+      # If you create your own checks, you must specify the source files for
+      # them here, so they can be loaded by Credo before running the analysis.
+      #
+      requires: [],
+      #
+      # If you want to enforce a style guide and need a more traditional linting
+      # experience, you can change `strict` to `true` below:
+      #
+      strict: false,
+      #
+      # If you want to use uncolored output by default, you can change `color`
+      # to `false` below:
+      #
+      color: true,
+      #
+      # You can customize the parameters of any check by adding a second element
+      # to the tuple.
+      #
+      # To disable a check put `false` as second element:
+      #
+      #     {Credo.Check.Design.DuplicatedCode, false}
+      #
+      checks: [
+        #
+        ## Consistency Checks
+        #
+        {Credo.Check.Consistency.ExceptionNames, []},
+        {Credo.Check.Consistency.LineEndings, []},
+        {Credo.Check.Consistency.ParameterPatternMatching, false},
+        {Credo.Check.Consistency.SpaceAroundOperators, []},
+        {Credo.Check.Consistency.SpaceInParentheses, []},
+        {Credo.Check.Consistency.TabsOrSpaces, []},
+
+        #
+        ## Design Checks
+        #
+        # You can customize the priority of any check
+        # Priority values are: `low, normal, high, higher`
+        #
+        {Credo.Check.Design.AliasUsage,
+         [priority: :low, if_nested_deeper_than: 2, if_called_more_often_than: 0]},
+        # You can also customize the exit_status of each check.
+        # If you don't want TODO comments to cause `mix credo` to fail, just
+        # set this value to 0 (zero).
+        #
+        {Credo.Check.Design.TagTODO, [exit_status: 0]},
+        {Credo.Check.Design.TagFIXME, []},
+
+        #
+        ## Readability Checks
+        #
+        {Credo.Check.Readability.AliasOrder, []},
+        {Credo.Check.Readability.FunctionNames, []},
+        {Credo.Check.Readability.LargeNumbers, []},
+        {Credo.Check.Readability.MaxLineLength, [priority: :normal, max_length: 90]},
+        {Credo.Check.Readability.ModuleAttributeNames, []},
+        {Credo.Check.Readability.ModuleDoc, []},
+        {Credo.Check.Readability.ModuleNames, []},
+        {Credo.Check.Readability.ParenthesesInCondition, []},
+        {Credo.Check.Readability.ParenthesesOnZeroArityDefs, []},
+        {Credo.Check.Readability.PredicateFunctionNames, []},
+        {Credo.Check.Readability.PreferImplicitTry, []},
+        {Credo.Check.Readability.RedundantBlankLines, []},
+        {Credo.Check.Readability.Semicolons, []},
+        {Credo.Check.Readability.SpaceAfterCommas, []},
+        {Credo.Check.Readability.StringSigils, []},
+        {Credo.Check.Readability.TrailingBlankLine, []},
+        {Credo.Check.Readability.TrailingWhiteSpace, []},
+        {Credo.Check.Readability.VariableNames, []},
+
+        #
+        ## Refactoring Opportunities
+        #
+        {Credo.Check.Refactor.CondStatements, []},
+        {Credo.Check.Refactor.CyclomaticComplexity, false},
+        {Credo.Check.Refactor.FunctionArity, []},
+        {Credo.Check.Refactor.LongQuoteBlocks, false},
+        {Credo.Check.Refactor.MapInto, []},
+        {Credo.Check.Refactor.MatchInCondition, []},
+        {Credo.Check.Refactor.NegatedConditionsInUnless, []},
+        {Credo.Check.Refactor.NegatedConditionsWithElse, []},
+        {Credo.Check.Refactor.Nesting, false},
+        {Credo.Check.Refactor.PipeChainStart,
+         [excluded_argument_types: [:atom, :binary, :fn, :keyword], excluded_functions: []]},
+        {Credo.Check.Refactor.UnlessWithElse, []},
+
+        #
+        ## Warnings
+        #
+        {Credo.Check.Warning.BoolOperationOnSameValues, []},
+        {Credo.Check.Warning.ExpensiveEmptyEnumCheck, []},
+        {Credo.Check.Warning.IExPry, []},
+        {Credo.Check.Warning.IoInspect, []},
+        {Credo.Check.Warning.LazyLogging, []},
+        {Credo.Check.Warning.OperationOnSameValues, []},
+        {Credo.Check.Warning.OperationWithConstantResult, []},
+        {Credo.Check.Warning.RaiseInsideRescue, []},
+        {Credo.Check.Warning.UnusedEnumOperation, []},
+        {Credo.Check.Warning.UnusedFileOperation, []},
+        {Credo.Check.Warning.UnusedKeywordOperation, []},
+        {Credo.Check.Warning.UnusedListOperation, []},
+        {Credo.Check.Warning.UnusedPathOperation, []},
+        {Credo.Check.Warning.UnusedRegexOperation, []},
+        {Credo.Check.Warning.UnusedStringOperation, []},
+        {Credo.Check.Warning.UnusedTupleOperation, []},
+
+        #
+        # Controversial and experimental checks (opt-in, just remove `, false`)
+        #
+        {Credo.Check.Consistency.MultiAliasImportRequireUse, false},
+        {Credo.Check.Design.DuplicatedCode, false},
+        {Credo.Check.Readability.Specs, false},
+        {Credo.Check.Refactor.ABCSize, false},
+        {Credo.Check.Refactor.AppendSingleItem, false},
+        {Credo.Check.Refactor.DoubleBooleanNegation, false},
+        {Credo.Check.Refactor.VariableRebinding, false},
+        {Credo.Check.Warning.MapGetUnsafePass, false},
+        {Credo.Check.Warning.UnsafeToAtom, false}
+
+        #
+        # Custom checks can be created using `mix credo.gen.check`.
+        #
+      ]
+    }
+  ]
+}

test/elixir/.formatter.exs

@@ -1,6 +1,6 @@
 # Used by "mix format"
 [
   inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"],
-  line_length: 120,
+  line_length: 90,
   rename_deprecated_at: "1.5.0"
 ]

test/elixir/lib/couch.ex

@@ -1,4 +1,8 @@
 defmodule Couch.Session do
+  @moduledoc """
+  CouchDB session helpers.
+  """
+
   @enforce_keys [:cookie]
   defstruct [:cookie]
 
@@ -155,18 +159,41 @@ defmodule Couch do
     options = process_options(options)
 
     body = Keyword.get(options, :body, "")
-    headers = Keyword.merge(Application.get_env(:httpotion, :default_headers, []), Keyword.get(options, :headers, []))
-    timeout = Keyword.get(options, :timeout, Application.get_env(:httpotion, :default_timeout, 5000))
+
+    headers =
+      Keyword.merge(
+        Application.get_env(:httpotion, :default_headers, []),
+        Keyword.get(options, :headers, [])
+      )
+
+    timeout =
+      Keyword.get(
+        options,
+        :timeout,
+        Application.get_env(:httpotion, :default_timeout, 5000)
+      )
 
     ib_options =
-      Keyword.merge(Application.get_env(:httpotion, :default_ibrowse, []), Keyword.get(options, :ibrowse, []))
+      Keyword.merge(
+        Application.get_env(:httpotion, :default_ibrowse, []),
+        Keyword.get(options, :ibrowse, [])
+      )
 
     follow_redirects =
-      Keyword.get(options, :follow_redirects, Application.get_env(:httpotion, :default_follow_redirects, false))
+      Keyword.get(
+        options,
+        :follow_redirects,
+        Application.get_env(:httpotion, :default_follow_redirects, false)
+      )
 
     ib_options =
       if stream_to = Keyword.get(options, :stream_to),
-        do: Keyword.put(ib_options, :stream_to, spawn(__MODULE__, :transformer, [stream_to, method, url, options])),
+        do:
+          Keyword.put(
+            ib_options,
+            :stream_to,
+            spawn(__MODULE__, :transformer, [stream_to, method, url, options])
+          ),
         else: ib_options
 
     ib_options =
@@ -182,7 +209,9 @@ defmodule Couch do
       url: url |> to_string |> process_url(options) |> to_charlist,
       body: body |> process_request_body,
       headers:
-        headers |> process_request_headers(options) |> Enum.map(fn {k, v} -> {to_charlist(k), to_charlist(v)} end),
+        headers
+        |> process_request_headers(options)
+        |> Enum.map(fn {k, v} -> {to_charlist(k), to_charlist(v)} end),
       timeout: timeout,
       ib_options: ib_options,
       follow_redirects: follow_redirects

test/elixir/mix.exs

@@ -23,7 +23,8 @@ defmodule Foo.Mixfile do
     [
       # {:dep_from_hexpm, "~> 0.3.0"},
       {:httpotion, "~> 3.0"},
-      {:jiffy, "~> 0.15.2"}
+      {:jiffy, "~> 0.15.2"},
+      {:credo, "~> 1.0.0", only: [:dev, :test], runtime: false}
       # {:dep_from_git, git: "https://github.com/elixir-lang/my_dep.git", tag: "0.1.0"},
     ]
   end

test/elixir/mix.lock

@@ -1,5 +1,8 @@
 %{
+  "bunt": {:hex, :bunt, "0.2.0", "951c6e801e8b1d2cbe58ebbd3e616a869061ddadcc4863d0a2182541acae9a38", [:mix], [], "hexpm"},
+  "credo": {:hex, :credo, "1.0.0", "aaa40fdd0543a0cf8080e8c5949d8c25f0a24e4fc8c1d83d06c388f5e5e0ea42", [:mix], [{:bunt, "~> 0.2.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm"},
   "httpotion": {:hex, :httpotion, "3.1.0", "14d20d9b0ce4e86e253eb91e4af79e469ad949f57a5d23c0a51b2f86559f6589", [:mix], [{:ibrowse, "~> 4.4", [hex: :ibrowse, repo: "hexpm", optional: false]}], "hexpm"},
   "ibrowse": {:hex, :ibrowse, "4.4.1", "2b7d0637b0f8b9b4182de4bd0f2e826a4da2c9b04898b6e15659ba921a8d6ec2", [:rebar3], [], "hexpm"},
+  "jason": {:hex, :jason, "1.1.2", "b03dedea67a99223a2eaf9f1264ce37154564de899fd3d8b9a21b1a6fd64afe7", [:mix], [{:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm"},
   "jiffy": {:hex, :jiffy, "0.15.2", "de266c390111fd4ea28b9302f0bc3d7472468f3b8e0aceabfbefa26d08cd73b7", [:rebar3], [], "hexpm"},
 }