Show informative error message when a merge conflict is detected in a…

… YAML file. This fixes issue CocoaPods#69.

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

spec/yaml_converter_spec.rb → spec/yaml_helper_spec.rb

@@ -24,50 +24,91 @@ def sample_yaml
   LOCKFILE
 end
 
+def yaml_with_merge_conflict
+  text = <<-LOCKFILE.strip_heredoc
+    PODS:
+      - Kiwi (2.2)
+      - ObjectiveSugar (1.1.1)
+
+    DEPENDENCIES:
+      - Kiwi
+      - ObjectiveSugar (from `../`)
+
+    EXTERNAL SOURCES:
+      ObjectiveSugar:
+        :path: ../
+
+    SPEC CHECKSUMS:
+    <<<<<<< HEAD
+      Kiwi: 05f988748c5136c6daed8dab3563eca929399a72
+      ObjectiveSugar: 7377622e35ec89ce893b05dd0af4bede211b01a4
+    =======
+      Kiwi: db174bba4ee8068b15d7122f1b22fb64b7c1d378
+      ObjectiveSugar: 27c680bb74f0b0415e9e743d5d61d77bc3292d3f
+    >>>>>>> b65623cbf5e105acbc3e2dec48f8024fa82003ce
+
+    COCOAPODS: 0.29.0
+  LOCKFILE
+end
+
+def bad_yaml
+  text = <<-LOCKFILE.strip_heredoc
+    PODS:
+      - Kiwi (2.2)
+      SOME BAD TEXT
+      
+    DEPENDENCIES:
+      - Kiwi
+      - ObjectiveSugar (from `../`)
+      
+    COCOAPODS: 0.29.0
+  LOCKFILE
+end
+
 #-----------------------------------------------------------------------------#
 
 module Pod
   describe 'In general' do
 
-    describe YAMLConverter do
+    describe YAMLHelper do
 
       it 'converts a string' do
         value = 'Value'
-        result = YAMLConverter.convert(value)
+        result = YAMLHelper.convert(value)
         result.should == "Value\n"
       end
 
       it 'converts a symbol' do
         value = :value
-        result = YAMLConverter.convert(value)
+        result = YAMLHelper.convert(value)
         result.should == ":value\n"
       end
 
       it 'converts the true class' do
-        result = YAMLConverter.convert(true)
+        result = YAMLHelper.convert(true)
         result.should == "true\n"
       end
 
       it 'converts the false class' do
-        result = YAMLConverter.convert(false)
+        result = YAMLHelper.convert(false)
         result.should == "false\n"
       end
 
       it 'converts an array' do
         value = %w(Value_1 Value_2)
-        result = YAMLConverter.convert(value)
+        result = YAMLHelper.convert(value)
         result.should == "- Value_1\n- Value_2\n"
       end
 
       it 'converts an hash' do
         value = { 'Key' => 'Value' }
-        result = YAMLConverter.convert(value)
+        result = YAMLHelper.convert(value)
         result.should == "Key: Value\n"
       end
 
       it 'converts an hash which contains and array as one of the values' do
         value = { 'Key' => %w(Value_1 Value_2) }
-        result = YAMLConverter.convert(value)
+        result = YAMLHelper.convert(value)
         result.should == <<-EOT.strip_heredoc
         Key:
           - Value_1
@@ -77,7 +118,7 @@ module Pod
 
       it 'converts an hash which contains and array as one of the values' do
         value = { 'Key' => { 'Subkey' => %w(Value_1 Value_2) } }
-        result = YAMLConverter.convert(value)
+        result = YAMLHelper.convert(value)
         result.should == <<-EOT.strip_heredoc
         Key:
           Subkey:
@@ -89,8 +130,30 @@ module Pod
       it "raises if it can't handle the class of the given object" do
         value = Pathname.new('a-path')
         should.raise StandardError do
-          YAMLConverter.convert(value)
+          YAMLHelper.convert(value)
         end.message.should.match /Unsupported class/
+      end      
+    end
+
+    #-------------------------------------------------------------------------#
+
+    describe 'Loading' do
+      it "raises an Informative error when it encounters a merge conflict" do
+        should.raise Informative do
+          YAMLHelper.load(yaml_with_merge_conflict)
+        end.message.should.match /Merge conflict\(s\) detected/
+      end
+
+      it "raises another error when it encounters an error that is not a merge conflict" do
+        should.raise do
+          YAMLHelper.load(bad_yaml)
+        end
+      end
+
+      it "should not raise when there is no merge conflict" do
+        should.not.raise do
+          YAMLHelper.load(sample_yaml)
+        end
       end
     end
 
@@ -101,27 +164,27 @@ module Pod
       describe '#sorted_array_with_hint' do
         it 'sorts an array according to its string representation' do
           values = %w(JSONKit BananaLib)
-          result = YAMLConverter.send(:sorted_array, values)
+          result = YAMLHelper.send(:sorted_array, values)
           result.should == %w(BananaLib JSONKit)
         end
 
         it 'sorts an array containing strings and hashes according to its string representation' do
           values = ['JSONKit', 'BananaLib', { 'c_hash_key' => 'a_value' }]
-          result = YAMLConverter.send(:sorted_array, values)
+          result = YAMLHelper.send(:sorted_array, values)
           result.should == ['BananaLib', { 'c_hash_key' => 'a_value' }, 'JSONKit']
         end
 
         it 'sorts an array with a given hint' do
           values = %w(non-hinted second first)
           hint = %w(first second hinted-missing)
-          result = YAMLConverter.send(:sorted_array_with_hint, values, hint)
+          result = YAMLHelper.send(:sorted_array_with_hint, values, hint)
           result.should == %w(first second non-hinted)
         end
 
         it 'sorts an array with a given nil hint' do
           values = %w(JSONKit BananaLib)
           hint = nil
-          result = YAMLConverter.send(:sorted_array_with_hint, values, hint)
+          result = YAMLHelper.send(:sorted_array_with_hint, values, hint)
           result.should == %w(BananaLib JSONKit)
         end
       end
@@ -130,25 +193,25 @@ module Pod
 
         it 'returns the empty string if a nil value is passed' do
           value = nil
-          result = YAMLConverter.send(:sorting_string, value)
+          result = YAMLHelper.send(:sorting_string, value)
           result.should == ''
         end
 
         it 'sorts strings ignoring case' do
           value = 'String'
-          result = YAMLConverter.send(:sorting_string, value)
+          result = YAMLHelper.send(:sorting_string, value)
           result.should == 'string'
         end
 
         it 'sorts symbols ignoring case' do
           value = :Symbol
-          result = YAMLConverter.send(:sorting_string, value)
+          result = YAMLHelper.send(:sorting_string, value)
           result.should == 'symbol'
         end
 
         it 'sorts arrays using the first element ignoring case' do
           value = %w(String_2 String_1)
-          result = YAMLConverter.send(:sorting_string, value)
+          result = YAMLHelper.send(:sorting_string, value)
           result.should == 'string_2'
         end
 
@@ -157,7 +220,7 @@ module Pod
             :key_2 => 'a_value',
             :key_1 => 'a_value',
           }
-          result = YAMLConverter.send(:sorting_string, value)
+          result = YAMLHelper.send(:sorting_string, value)
           result.should == 'key_1'
         end
       end
@@ -168,10 +231,10 @@ module Pod
     describe 'Lockfile generation' do
 
       it 'converts a complex file' do
-        value = YAML.load(sample_yaml)
+        value = YAMLHelper.load(sample_yaml)
         sorted_keys = ['PODS', 'DEPENDENCIES', 'EXTERNAL SOURCES', 'SPEC CHECKSUMS', 'COCOAPODS']
-        result = YAMLConverter.convert_hash(value, sorted_keys, "\n\n")
-        YAML.load(result).should == value
+        result = YAMLHelper.convert_hash(value, sorted_keys, "\n\n")
+        YAMLHelper.load(result).should == value
         result.should == sample_yaml
       end
     end