Parse scopes with Symbol keys.

lib/cuprum/collections/rspec/contracts/scopes/criteria_contracts.rb

@@ -524,7 +524,9 @@ module ShouldParseCriteriaFromABlockContract
         end
 
         describe 'with a block returning nil' do
-          let(:error_message) { 'value must be a Hash with String keys' }
+          let(:error_message) do
+            'value must be a Hash with String or Symbol keys'
+          end
 
           it 'should raise an exception' do
             expect { parse_criteria { nil } }
@@ -533,7 +535,9 @@ module ShouldParseCriteriaFromABlockContract
         end
 
         describe 'with a block returning an Object' do
-          let(:error_message) { 'value must be a Hash with String keys' }
+          let(:error_message) do
+            'value must be a Hash with String or Symbol keys'
+          end
 
           it 'should raise an exception' do
             expect { parse_criteria { Object.new.freeze } }
@@ -542,7 +546,9 @@ module ShouldParseCriteriaFromABlockContract
         end
 
         describe 'with a block returning a Hash with invalid keys' do
-          let(:error_message) { 'value must be a Hash with String keys' }
+          let(:error_message) do
+            'value must be a Hash with String or Symbol keys'
+          end
           let(:block)         { -> { { nil => 'invalid' } } }
 
           it 'should raise an exception' do
@@ -569,7 +575,7 @@ module ShouldParseCriteriaFromABlockContract
           it { expect(parse_criteria(&block)).to be == expected }
         end
 
-        describe 'with a Hash with many keys' do
+        describe 'with a Hash with many String keys' do
           let(:operators) { Cuprum::Collections::Queries::Operators }
           let(:block) do
             lambda do
@@ -591,6 +597,28 @@ module ShouldParseCriteriaFromABlockContract
           it { expect(parse_criteria(&block)).to be == expected }
         end
 
+        describe 'with a Hash with many Symbol keys' do
+          let(:operators) { Cuprum::Collections::Queries::Operators }
+          let(:block) do
+            lambda do
+              {
+                title:  'A Wizard of Earthsea',
+                author: 'Ursula K. LeGuin',
+                series: 'Earthsea'
+              }
+            end
+          end
+          let(:expected) do
+            [
+              ['title', operators::EQUAL, 'A Wizard of Earthsea'],
+              ['author', operators::EQUAL, 'Ursula K. LeGuin'],
+              ['series', operators::EQUAL, 'Earthsea']
+            ]
+          end
+
+          it { expect(parse_criteria(&block)).to be == expected }
+        end
+
         describe 'with a Hash with an "eq" operator' do
           let(:operators) { Cuprum::Collections::Queries::Operators }
           let(:block) do
@@ -954,7 +982,9 @@ module ShouldParseCriteriaFromAHashContract
       #     which the contract is applied.
       contract do
         describe 'with nil' do
-          let(:error_message) { 'value must be a Hash with String keys' }
+          let(:error_message) do
+            'value must be a Hash with String or Symbol keys'
+          end
 
           it 'should raise an exception' do
             expect { parse_criteria(nil) }
@@ -963,7 +993,9 @@ module ShouldParseCriteriaFromAHashContract
         end
 
         describe 'with an Object' do
-          let(:error_message) { 'value must be a Hash with String keys' }
+          let(:error_message) do
+            'value must be a Hash with String or Symbol keys'
+          end
 
           it 'should raise an exception' do
             expect { parse_criteria(Object.new.freeze) }
@@ -972,7 +1004,9 @@ module ShouldParseCriteriaFromAHashContract
         end
 
         describe 'with a Hash with invalid keys' do
-          let(:error_message) { 'value must be a Hash with String keys' }
+          let(:error_message) do
+            'value must be a Hash with String or Symbol keys'
+          end
           let(:value)         { { nil => 'invalid' } }
 
           it 'should raise an exception' do
@@ -999,7 +1033,7 @@ module ShouldParseCriteriaFromAHashContract
           it { expect(parse_criteria(value)).to be == expected }
         end
 
-        describe 'with a Hash with many keys' do
+        describe 'with a Hash with many String keys' do
           let(:operators) { Cuprum::Collections::Queries::Operators }
           let(:value) do
             {
@@ -1018,6 +1052,26 @@ module ShouldParseCriteriaFromAHashContract
 
           it { expect(parse_criteria(value)).to be == expected }
         end
+
+        describe 'with a Hash with many Symbol keys' do
+          let(:operators) { Cuprum::Collections::Queries::Operators }
+          let(:value) do
+            {
+              title:  'A Wizard of Earthsea',
+              author: 'Ursula K. LeGuin',
+              series: 'Earthsea'
+            }
+          end
+          let(:expected) do
+            [
+              ['title', operators::EQUAL, 'A Wizard of Earthsea'],
+              ['author', operators::EQUAL, 'Ursula K. LeGuin'],
+              ['series', operators::EQUAL, 'Earthsea']
+            ]
+          end
+
+          it { expect(parse_criteria(value)).to be == expected }
+        end
       end
     end
   end

lib/cuprum/collections/scopes/criteria.rb

@@ -34,27 +34,38 @@ def parse(*args, &block)
     end
 
     # Helper for generating criteria from hash or block inputs.
-    class Parser
+    class Parser # rubocop:disable Metrics/ClassLength
       OperatorExpression = Struct.new(:operator, :value)
       private_constant :OperatorExpression
 
       UNKNOWN = Object.new.freeze
       private_constant :UNKNOWN
 
-      # @return [Cuprum::Collections::Scopes::Criteria::Parser] a singleton
-      #   instance of the parser class.
-      def self.instance
-        @instance ||= new
-      end
+      class << self
+        # @return [Cuprum::Collections::Scopes::Criteria::Parser] a singleton
+        #   instance of the parser class.
+        def instance
+          @instance ||= new
+        end
+
+        # @private
+        def validate_hash(value)
+          return if valid_hash?(value)
+
+          raise ArgumentError,
+            'value must be a Hash with String or Symbol keys',
+            caller(1..-1)
+        end
 
-      # @private
-      def self.validate_hash(value)
-        return if value.is_a?(Hash) &&
-                  value.each_key.all? { |key| key.is_a?(String) }
+        private
 
-        raise ArgumentError,
-          'value must be a Hash with String keys',
-          caller(1..-1)
+        def valid_hash?(value)
+          return false unless value.is_a?(Hash)
+
+          value.each_key.all? do |key|
+            key.is_a?(String) || key.is_a?(Symbol)
+          end
+        end
       end
 
       # @override parse(value = nil, &block)
@@ -101,9 +112,11 @@ def parse_block(...) # rubocop:disable Metrics/MethodLength
 
         value.map do |attribute, filter|
           if filter.is_a?(OperatorExpression)
-            [attribute, filter.operator, filter.value]
+            [attribute.to_s, filter.operator, filter.value]
           else
-            [attribute, Cuprum::Collections::Queries::Operators::EQUAL, filter]
+            operator = Cuprum::Collections::Queries::Operators::EQUAL
+
+            [attribute.to_s, operator, filter]
           end
         end
       rescue NameError => exception
@@ -118,8 +131,10 @@ def parse_block(...) # rubocop:disable Metrics/MethodLength
       def parse_hash(value)
         Parser.validate_hash(value)
 
+        operator = Cuprum::Collections::Queries::Operators::EQUAL
+
         value.map do |attribute, filter|
-          [attribute, Cuprum::Collections::Queries::Operators::EQUAL, filter]
+          [attribute.to_s, operator, filter]
         end
       end