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