Add ErrorCollector object to Pipes::Context

codequest_pipes.gemspec

@@ -2,7 +2,7 @@
 
 Gem::Specification.new do |spec|
   spec.name    = 'codequest_pipes'
-  spec.version = '0.3.1.1'
+  spec.version = '0.3.2'
 
   spec.author      = 'codequest'
   spec.email       = 'hello@codequest.com'

lib/codequest_pipes/context.rb

@@ -1,10 +1,10 @@
+require 'codequest_pipes/context/error_collector'
+
 module Pipes
   # Context is an object used to pass data between Pipes. It behaves like an
   # OpenStruct except you can write a value only once - this way we prevent
   # context keys from being overwritten.
   class Context
-    attr_reader :error
-
     # Override is an exception raised when an attempt is made to override an
     # existing Context property.
     class Override < ::StandardError; end
@@ -18,7 +18,7 @@ class ExecutionTerminated < ::StandardError; end
     # @param values [Hash]
     def initialize(values = {})
       add(values)
-      @error = nil
+      @error_collector = ErrorCollector.new
     end
 
     # Method `add` allows adding new properties (as a Hash) to the Context.
@@ -32,31 +32,28 @@ def add(values)
       end
     end
 
-    # Quietly fail the pipe, allowing the error to be saved and accessed from
-    # the Context.
+    # Quietly fail the pipe. The error will be passed to the error_collector
+    # and stored in the :base errors collection.
     #
-    # @param error [Any] Error to be set.
+    ## @param error [String]
     def halt(error = 'Execution stopped')
-      @error = error
+      add_errors(base: error)
     end
 
-    # Explicitly fail the pipe, allowing the error to be saved and accessed from
-    # the Context.
-    #
-    # @param error [Any] Error to be set.
+    # Explicitly fail the pipe.
     #
     # @raise [ExecutionTerminated]
     def terminate(error)
       halt(error)
-      fail ExecutionTerminated, error
+      fail ExecutionTerminated
     end
 
     # Check if the Context finished successfully.
     # This method smells of :reek:NilCheck
     #
     # @return [Boolean] Success status.
     def success?
-      @error.nil?
+      errors.empty?
     end
 
     # Check if the Context failed.
@@ -73,9 +70,37 @@ def failure?
     def inspect
       keys = methods - Object.methods - Pipes::Context.instance_methods
       fields = keys.map { |key| "#{key}=#{public_send(key).inspect}" }
-      fields << "@error=#{@error.inspect}"
+      fields << "@errors=#{@errors.inspect}"
       object_id_hex = '%x' % (object_id << 1)
       "#<Pipes::Context:0x00#{object_id_hex} #{fields.join(', ')}>"
     end
+
+    # Return errors from ErrorCollector object.
+    #
+    # @return [Hash]
+    def errors
+      error_collector.errors
+    end
+
+    # This method is added to maintain backwards compatibility - previous
+    # versions implemented a single @error instance variable of String for error
+    # storage.
+    #
+    # @return [String]
+    def error
+      errors[:base]&.first
+    end
+
+    # Add errors to ErrorCollector object.
+    # It doesn't fail the pipe as opposed to `halt` and `terminate` methods.
+    #
+    # @param collectable_errors [Hash]
+    def add_errors(collectable_errors)
+      error_collector.add(collectable_errors)
+    end
+
+    private
+
+    attr_reader :error_collector
   end # class Context
 end # module Pipes

lib/codequest_pipes/context/error_collector.rb

@@ -0,0 +1,20 @@
+module Pipes
+  class Context
+    # ErrorCollector is Context's companion object for storing non-critical
+    # errors.
+    class ErrorCollector
+      attr_reader :errors
+
+      def initialize
+        @errors = {}
+      end
+
+      def add(errors_hash)
+        errors_hash.map do |key, errors|
+          @errors[key] ||= []
+          @errors[key] = @errors[key] | Array(errors)
+        end
+      end
+    end # class ErrorColletor
+  end # class Context
+end # module Pipes

lib/codequest_pipes/pipe.rb

@@ -20,7 +20,7 @@ def self.|(other)
     end
 
     def self.call(ctx)
-      return ctx if ctx.error
+      return ctx if ctx.errors.any?
       _validate_ctx(_required_context_elements, ctx)
       new(ctx).call
       _validate_ctx(_provided_context_elements, ctx)

spec/context_spec.rb

@@ -18,13 +18,34 @@
     it 'lists all fields' do
       subject.add(bacon: 'yum', raisins: 'bleh')
       expect(subject.inspect)
-        .to match(/bacon=\"yum\", raisins=\"bleh\", @error=nil/)
+        .to match(/bacon=\"yum\", raisins=\"bleh\", @errors=nil/)
     end
 
     it 'lists nested contexts' do
       subject.add(nested: Pipes::Context.new(foo: 'bar'))
       expect(subject.inspect)
-        .to match(/nested=#<Pipes::Context:0x\w+ foo="bar", @error=nil>,/)
+        .to match(/nested=#<Pipes::Context:0x\w+ foo="bar", @errors=nil>,/)
     end
   end # describe '#inspect'
+
+  describe '#add_errors' do
+    it 'adds error to error_collector' do
+      subject.add_errors(base: 'Error message')
+      subject.add_errors(
+        base: ['Another error message'],
+        user: 'User error message'
+      )
+      expect(subject.errors).to eq(
+        base: ['Error message', 'Another error message'],
+        user: ['User error message']
+      )
+    end
+  end # describe '#add_errors'
+
+  describe '#halt' do
+    it 'adds error to error collector :base' do
+      subject.halt('Some error')
+      expect(subject.error).to eq('Some error')
+    end
+  end # describe '#halt'
 end # describe Pipes::Context

spec/matcher_spec.rb

@@ -13,7 +13,7 @@
   shared_examples_for 'fails_with_message' do |message|
     it 'fails' do
       expected_message =
-        message || /expected #<Pipes::Context:.+ @error=nil> to match/
+        message || /expected #<Pipes::Context:.+ @errors=nil> to match/
       expect { expect(ctx).to match(pipe_context(expected)) }
         .to fail_with(expected_message)
     end