[Validator] Check file suffix of module_map

lib/cocoapods/validator.rb

@@ -419,8 +419,14 @@ module Pod
     end
 
     def _validate_module_map
-      if spec.module_map && !file_accessor.module_map.exist?
-        error('module_map', 'Unable to find the specified module map file.')
+      if spec.module_map
+        unless file_accessor.module_map.exist?
+          error('module_map', 'Unable to find the specified module map file.')
+        end
+        unless file_accessor.module_map.extname == '.modulemap'
+          relative_path = file_accessor.module_map.relative_path_from file_accessor.root
+          error('module_map', "Unexpected file extension for modulemap file (#{relative_path}).")
+        end
       end
     end
 

spec/unit/validator_spec.rb

@@ -455,6 +455,16 @@ module Pod
           validator.results.map(&:to_s).first.should.match /Unable to find the specified module map file./
           validator.result_type.should == :error
         end
+
+        it 'checks module_map accepts only modulemaps' do
+          file = write_podspec(stub_podspec(/.*source_files.*/, '"source_files": "JSONKit.*", "module_map": "JSONKit.m",'))
+          validator = Validator.new(file, SourcesManager.master.map(&:url))
+          validator.stubs(:build_pod)
+          validator.stubs(:validate_url)
+          validator.validate
+          validator.results.map(&:to_s).first.should.match /Unexpected file extension for modulemap file \(JSONKit\.m\)/
+          validator.result_type.should == :error
+        end
       end
 
       it 'validates a podspec with dependencies' do