Show informative error message when a merge conflict is detected in a YAML file.

CHANGELOG.md

@@ -4,6 +4,11 @@
 
 ##### Enhancements
 
+* Show informative error message when a merge conflict is detected in a YAML file.
+  [Luis de la Rosa](https://github.com/luisdelarosa)
+  [#69](https://github.com/CocoaPods/Core/issues/69)
+  [#100](https://github.com/CocoaPods/Core/pull/100)
+
 * Added a check to the linter to ensure that the `social_media_url` has 
   been changed from the example value.  
   [Richard Lee](https://github.com/dlackty)

lib/cocoapods-core.rb

@@ -28,7 +28,7 @@ class Informative < PlainInformative; end
   autoload :Source,         'cocoapods-core/source'
   autoload :Specification,  'cocoapods-core/specification'
   autoload :StandardError,  'cocoapods-core/standard_error'
-  autoload :YAMLConverter,  'cocoapods-core/yaml_converter'
+  autoload :YAMLHelper,  'cocoapods-core/yaml_helper'
 
   # TODO: Fix
   #

lib/cocoapods-core/lockfile.rb

@@ -40,7 +40,7 @@ def initialize(hash)
     def self.from_file(path)
       return nil unless path.exist?
       require 'yaml'
-      hash = File.open(path) { |f| YAML.load(f) }
+      hash = File.open(path) { |f| YAMLHelper.load(f) }
       unless hash && hash.is_a?(Hash)
         raise Informative, "Invalid Lockfile in `#{path}`"
       end
@@ -312,7 +312,7 @@ def to_yaml
         'SPEC CHECKSUMS',
         'COCOAPODS',
       ]
-      YAMLConverter.convert_hash(to_hash, keys_hint, "\n\n")
+      YAMLHelper.convert_hash(to_hash, keys_hint, "\n\n")
     end
 
     #-------------------------------------------------------------------------#

lib/cocoapods-core/podfile.rb

@@ -266,7 +266,7 @@ def self.from_yaml(path)
       if string.respond_to?(:encoding) && string.encoding.name != 'UTF-8'
         string.encode!('UTF-8')
       end
-      hash = YAML.load(string)
+      hash = YAMLHelper.load(string)
       from_hash(hash, path)
     end
 

lib/cocoapods-core/specification/set/statistics.rb

@@ -155,7 +155,7 @@ def github_pushed_at(set)
         def cache
           unless @cache
             if cache_file && cache_file.exist?
-              @cache = YAML.load(cache_file.read)
+              @cache = YAMLHelper.load(cache_file.read)
             else
               @cache = {}
             end

lib/cocoapods-core/yaml_converter.rb → lib/cocoapods-core/yaml_helper.rb

@@ -15,7 +15,7 @@ module Pod
   #       The missing features include:
   #       - Strings are never quoted even when ambiguous.
   #
-  class YAMLConverter
+  class YAMLHelper
 
     class << self
 
@@ -41,6 +41,18 @@ def convert_hash(value, hash_keys_hint, line_separator = "\n")
         result << "\n"
       end
 
+      # Load a YAML file and provide more informative error messages in special cases like merge conflict.
+      # @param A YAML string.
+      def load(yaml_string)
+        YAML.load(yaml_string)
+        rescue Exception => exception
+          if yaml_has_merge_error(yaml_string)
+            raise Informative, 'Merge conflict(s) detected'
+          else
+            raise exception
+          end
+      end
+
       #-----------------------------------------------------------------------#
 
       private
@@ -120,6 +132,13 @@ def process_hash(hash, hash_keys_hint = nil, line_separator = "\n")
         key_lines * line_separator
       end
 
+      # Check for merge errors in a YAML string.
+      # @param A YAML string.
+      # @return If a merge error was detected or not.
+      def yaml_has_merge_error(yaml_string)
+        yaml_string.include?('<<<<<<< HEAD')
+      end
+
       #-----------------------------------------------------------------------#
 
       private

spec/lockfile_spec.rb

@@ -65,14 +65,14 @@ def self.specs
       end
 
       it 'stores the initialization hash' do
-        lockfile = Lockfile.new(YAML.load(Sample.yaml))
-        lockfile.internal_data.should == YAML.load(Sample.yaml)
+        lockfile = Lockfile.new(YAMLHelper.load(Sample.yaml))
+        lockfile.internal_data.should == YAMLHelper.load(Sample.yaml)
       end
 
       it 'loads from a file' do
         File.open(@tmp_path, 'w') { |f| f.write(Sample.yaml) }
         lockfile = Lockfile.from_file(@tmp_path)
-        lockfile.internal_data.should == YAML.load(Sample.yaml)
+        lockfile.internal_data.should == YAMLHelper.load(Sample.yaml)
       end
 
       it "returns nil if it can't find the initialization file" do
@@ -331,7 +331,7 @@ def self.specs
       end
 
       it 'generates a valid YAML representation' do
-        YAML.load(@lockfile.to_yaml).should == YAML.load(Sample.yaml)
+        YAMLHelper.load(@lockfile.to_yaml).should == YAMLHelper.load(Sample.yaml)
       end
 
       it "serializes correctly `:head' dependencies" do
@@ -414,7 +414,7 @@ def self.specs
       end
 
       it 'it includes all the information that it is expected to store' do
-        @lockfile.internal_data.should == YAML.load(Sample.yaml)
+        @lockfile.internal_data.should == YAMLHelper.load(Sample.yaml)
       end
     end
 

spec/podfile_spec.rb

@@ -196,7 +196,7 @@ module Pod
           generate_bridge_support: true
           set_arc_compatibility_flag: true
         EOF
-        YAML.load(podfile.to_yaml).should == YAML.load(expected)
+        YAMLHelper.load(podfile.to_yaml).should == YAMLHelper.load(expected)
       end
 
       it 'includes inhibit warnings per pod' do

spec/specification/set/statistics_spec.rb

@@ -95,14 +95,14 @@ module Pod
 
       it 'saves the cache after computing the creation date of a set' do
         @stats.creation_date(@set)
-        cache_hash = YAML.load(@cache_file.read)
+        cache_hash = YAMLHelper.load(@cache_file.read)
         cache_hash['JSONKit'][:creation_date].should == Time.parse('2011-09-12 10:49:04 +0200')
       end
 
       it 'saves the cache after computing the creation date of many sets' do
         sets = [@set, @source.search_by_name('libPusher').first]
         @stats.creation_dates(sets)
-        cache_hash = YAML.load(@cache_file.read)
+        cache_hash = YAMLHelper.load(@cache_file.read)
         cache_hash['JSONKit'][:creation_date].should == Time.parse('2011-09-12 10:49:04 +0200')
         cache_hash['libPusher'][:creation_date].should == Time.parse('2012-02-01 17:05:58 +0100')
       end
@@ -128,7 +128,7 @@ module Pod
 
       it 'saves the cache after retrieving GitHub information' do
         @stats.github_watchers(@set)
-        saved_cache = YAML.load(@cache_file.read)
+        saved_cache = YAMLHelper.load(@cache_file.read)
         saved_cache['JSONKit'][:gh_date] = nil
         @cache_hash['JSONKit'][:gh_date] = nil
         saved_cache.should == @cache_hash
@@ -141,7 +141,7 @@ module Pod
 
       it 'stores in the cache time of the last access to the GitHub API' do
         @stats.github_watchers(@set)
-        saved_cache = YAML.load(@cache_file.read)
+        saved_cache = YAMLHelper.load(@cache_file.read)
         time_delta = (Time.now - saved_cache['JSONKit'][:gh_date])
         time_delta.should < 60
       end