From 215fb85c7fc10d8fce504e5a7f6256d8a364e16c Mon Sep 17 00:00:00 2001
From: Benjamin Fleischer <benjamin.fleischer@swipesense.com>
Date: Tue, 18 Aug 2015 17:32:27 -0400
Subject: [PATCH] Test caller line parsing and digesting

---
 lib/active_model/serializer.rb | 25 +++++++++++++++++++++++--
 test/serializers/cache_test.rb | 27 ++++++++++++++++++++++++++-
 2 files changed, 49 insertions(+), 3 deletions(-)

diff --git a/lib/active_model/serializer.rb b/lib/active_model/serializer.rb
index d1ab351c5..1395b7781 100644
--- a/lib/active_model/serializer.rb
+++ b/lib/active_model/serializer.rb
@@ -12,6 +12,22 @@ class Serializer
     include Configuration
     include Associations
 
+
+    # Matches
+    #  "c:/git/emberjs/ember-crm-backend/app/serializers/lead_serializer.rb:1:in `<top (required)>'"
+    #  AND
+    #  "/c/git/emberjs/ember-crm-backend/app/serializers/lead_serializer.rb:1:in `<top (required)>'"
+    #  AS
+    #  c/git/emberjs/ember-crm-backend/app/serializers/lead_serializer.rb
+    CALLER_FILE = /
+      \A       # start of string
+      \S+      # one or more non-spaces
+      (?=      # stop previous match when
+        :\d+     # a colon is followed by one or more digits
+        :in      # followed by a colon followed by in
+      )
+    /x
+
     class << self
       attr_accessor :_attributes
       attr_accessor :_attributes_keys
@@ -29,8 +45,7 @@ def self.inherited(base)
       base._attributes = self._attributes.try(:dup) || []
       base._attributes_keys = self._attributes_keys.try(:dup) || {}
       base._urls = []
-      serializer_file_path = caller.first[/\A\S+(?=:\d+:in)/]
-      base._cache_digest = Digest::MD5.hexdigest(File.read(serializer_file_path))
+      base._cache_digest = digest_caller_file(caller.first)
       super
     end
 
@@ -161,6 +176,12 @@ def self.serializers_cache
       @serializers_cache ||= ThreadSafe::Cache.new
     end
 
+    def self.digest_caller_file(caller_line)
+      serializer_file_path = caller_line[CALLER_FILE]
+      serializer_file_contents = IO.read(serializer_file_path)
+      Digest::MD5.hexdigest(serializer_file_contents)
+    end
+
     attr_reader :options
 
     def self.get_serializer_for(klass)
diff --git a/test/serializers/cache_test.rb b/test/serializers/cache_test.rb
index 60c351944..a57faa2d1 100644
--- a/test/serializers/cache_test.rb
+++ b/test/serializers/cache_test.rb
@@ -1,4 +1,5 @@
 require 'test_helper'
+require 'tempfile'
 module ActiveModel
   class Serializer
     class CacheTest < Minitest::Test
@@ -125,10 +126,34 @@ def test_uses_file_digest_in_cache_key
         assert_equal(@blog_serializer.attributes, ActionController::Base.cache_store.fetch(@blog.cache_key_with_digest))
       end
 
-      def _cache_digest_definition
+      def test_cache_digest_definition
         assert_equal(::Model::FILE_DIGEST, @post_serializer.class._cache_digest)
       end
 
+      def test_serializer_file_path_on_nix
+        path = "/Users/git/emberjs/ember-crm-backend/app/serializers/lead_serializer.rb"
+        caller_line = "#{path}:1:in `<top (required)>'"
+        assert_equal caller_line[ActiveModel::Serializer::CALLER_FILE], path
+      end
+
+      def test_serializer_file_path_on_windows
+        path = "c:/git/emberjs/ember-crm-backend/app/serializers/lead_serializer.rb"
+        caller_line = "#{path}:1:in `<top (required)>'"
+        assert_equal caller_line[ActiveModel::Serializer::CALLER_FILE], path
+      end
+
+      def test_digest_caller_file
+        contents = "puts 'AMS rocks'!"
+        file = Tempfile.new("some_ruby.rb")
+        file.write(contents)
+        path = file.path
+        caller_line = "#{path}:1:in `<top (required)>'"
+        file.close
+        assert_equal ActiveModel::Serializer.digest_caller_file(caller_line), Digest::MD5.hexdigest(contents)
+      ensure
+        file.unlink
+      end
+
       private
       def render_object_with_cache(obj)
         ActiveModel::SerializableResource.new(obj).serializable_hash