Prototype.

lib/errapi.rb

@@ -1,3 +1,5 @@
 module Errapi
   VERSION = '0.1.0'
 end
+
+Dir[File.join File.dirname(__FILE__), File.basename(__FILE__, '.*'), '*.rb'].each{ |lib| require lib }

lib/errapi/validation_context.rb

@@ -0,0 +1,39 @@
+module Errapi
+
+  class ValidationContext
+    attr_reader :errors
+
+    def initialize
+      @errors = []
+    end
+
+    def add message, options = {}
+      @errors << ValidationError.new(message, options)
+    end
+
+    def error? criteria = {}
+      return !@errors.empty? if criteria.empty?
+
+      @errors.any? do |err|
+        string_matches?(err, criteria, :message) &&
+        value_matches?(err, criteria, :code) &&
+        string_matches?(err, criteria, :type) &&
+        string_matches?(err, criteria, :location)
+      end
+    end
+
+    private
+
+    def error_matches? err, criteria, attr, &block
+      !criteria.key?(attr) || block.call(err.send(attr), criteria[attr])
+    end
+
+    def value_matches? err, criteria, attr
+      error_matches?(err, criteria, attr){ |err_value,criterion| err_value == criterion }
+    end
+
+    def string_matches? err, criteria, attr
+      error_matches?(err, criteria, attr){ |err_value,criterion| criterion.kind_of?(Regexp) ? !err_value.match(criterion).nil? : err_value == criterion }
+    end
+  end
+end

lib/errapi/validation_error.rb

@@ -0,0 +1,13 @@
+module Errapi
+
+  class ValidationError
+    attr_accessor :message, :code, :type, :location
+
+    def initialize message, options = {}
+      @message = message
+      @code = options[:code]
+      @type = options[:type]
+      @location = options[:location]
+    end
+  end
+end

spec/validation_context_spec.rb

@@ -0,0 +1,33 @@
+require 'helper'
+
+RSpec.describe Errapi::ValidationContext do
+
+  it "should have an empty array of errors" do
+    expect(subject.errors).to eq([])
+  end
+
+  it "should indicate that there are no errors" do
+    expect(subject.error?).to be(false)
+  end
+
+  describe "with errors" do
+    before :each do
+      subject.add 'foo'
+      subject.add 'bar'
+      subject.add 'baz'
+    end
+
+    it "should match an error by message" do
+      expect(subject.error?(message: 'foo')).to be(true)
+      expect(subject.error?(message: 'bar')).to be(true)
+      expect(subject.error?(message: 'baz')).to be(true)
+      expect(subject.error?(message: 'qux')).to be(false)
+    end
+
+    it "should match an error by message with a regexp" do
+      expect(subject.error?(message: /foo/)).to be(true)
+      expect(subject.error?(message: /ba/)).to be(true)
+      expect(subject.error?(message: /q/)).to be(false)
+    end
+  end
+end

spec/validation_error_spec.rb

@@ -0,0 +1,24 @@
+require 'helper'
+
+RSpec.describe Errapi::ValidationError do
+  let(:options){ {} }
+  subject{ described_class.new 'foo', options }
+
+  it "should have a message" do
+    expect_error message: 'foo'
+  end
+
+  describe "with options" do
+    let(:options){ { code: 100, type: 'json', location: '/pointer' } }
+
+    it "should have a code, type and location" do
+      expect_error options.merge(message: 'foo')
+    end
+  end
+
+  def expect_error options = {}
+    [ :message, :code, :type, :location ].each do |attr|
+      expect(subject.send(attr)).to eq(options.key?(attr) ? options[attr] : nil)
+    end
+  end
+end