make json format approvals resilient to differences in pretty json fo…

…rmatting

lib/approvals.rb

@@ -13,6 +13,7 @@
 require 'approvals/reporters'
 require 'approvals/filter'
 require 'approvals/writer'
+require 'approvals/verifier'
 require 'approvals/namers/default_namer'
 
 module Approvals

lib/approvals/approval.rb

@@ -34,6 +34,10 @@ def writer
       @writer ||= Writer.for(@format)
     end
 
+    def verifier
+      @verifier ||= Verifier.for(@format)
+    end
+
     def verify
       unless File.exist?(namer.output_dir)
         FileUtils.mkdir_p(namer.output_dir)
@@ -63,6 +67,12 @@ def approved?
     BINARY_FORMATS = [:binary]
 
     def received_matches?
+      if Verifier.for(@format)
+        return Verifier.for(@format)
+          .new(received_path, approved_path)
+          .verify
+      end
+
       if BINARY_FORMATS.include?(@format) # Read without ERB
         IO.read(received_path).chomp == IO.read(approved_path).chomp
       else

lib/approvals/verifier.rb

@@ -0,0 +1,15 @@
+require 'approvals/verifiers/json_verifier'
+
+module Approvals
+  module Verifier
+    REGISTRY = {
+      json: Verifiers::JsonVerifier,
+    }
+
+    class << self
+      def for(format)
+        REGISTRY[format]
+      end
+    end
+  end
+end

lib/approvals/verifiers/json_verifier.rb

@@ -0,0 +1,27 @@
+module Approvals
+  module Verifiers
+    class JsonVerifier
+      def initialize(received_path, approved_path)
+        self.received_path = received_path
+        self.approved_path = approved_path
+      end
+
+      def verify
+        return false unless approved == received
+        true
+      end
+
+      private
+
+      attr_accessor :approved_path, :received_path
+
+      def approved
+        @approved = JSON.parse(File.read(approved_path))
+      end
+
+      def received
+        @receiver = JSON.parse(File.read(received_path))
+      end
+    end
+  end
+end

spec/approvals_spec.rb

@@ -105,6 +105,17 @@ def filter(data)
     Approvals.verify json, :format => :json, :namer => namer
   end
 
+  it "verifies json where the pretty generation is different but the content is the same" do
+    hash = { foo: {} }
+
+    Approvals.verify hash, :format => :json, :namer => namer
+  end
+
+  it "verifies json with a time object" do
+    hash = { foo: Time.new(2017,1,1) }
+
+    Approvals.verify hash, :format => :json, :namer => namer
+  end
 
   it "verifies json and is newline agnostic" do
     json = '{"pet":{"species":"turtle","color":"green","name":"Anthony"}}'

spec/fixtures/approvals/approvals_verifies_json_where_the_pretty_generation_is_different_but_the_content_is_the_same.approved.json

@@ -0,0 +1,6 @@
+{
+  "foo": {
+
+
+  }
+}

spec/fixtures/approvals/approvals_verifies_json_with_a_time_object.approved.json

@@ -0,0 +1,3 @@
+{
+  "foo": "2017-01-01 00:00:00 +0100"
+}

spec/fixtures/json_approval_with_different_whitespace/approved.json

@@ -0,0 +1,7 @@
+{
+  "foo": {
+
+
+
+  }
+}

spec/fixtures/json_approval_with_different_whitespace/received.json

@@ -0,0 +1,3 @@
+{
+  "foo": {}
+}

spec/fixtures/json_approval_with_different_whitespace/received_different_content.json

@@ -0,0 +1,3 @@
+{
+  "bar": 1
+}

spec/verifiers/json_verifier_spec.rb

@@ -0,0 +1,33 @@
+require 'spec_helper'
+
+describe Approvals::Verifiers::JsonVerifier do
+  subject(:instance) do
+    described_class.new(received_path, approved_path)
+  end
+
+  context "with same json content but different formatting" do
+    let(:received_path) do
+      "./spec/fixtures/json_approval_with_different_whitespace/received.json"
+    end
+    let(:approved_path) do
+      "./spec/fixtures/json_approval_with_different_whitespace/approved.json"
+    end
+
+    it "passes verification" do
+      expect(instance.verify).to be_truthy
+    end
+  end
+
+  context "with different json content" do
+    let(:received_path) do
+      "./spec/fixtures/json_approval_with_different_whitespace/received_different_content.json"
+    end
+    let(:approved_path) do
+      "./spec/fixtures/json_approval_with_different_whitespace/approved.json"
+    end
+
+    it "does not passe verification" do
+      expect(instance.verify).to be_falsy
+    end
+  end
+end