Integrate `swift_version` DSL support into pod targets

CHANGELOG.md

@@ -8,6 +8,10 @@ To install release candidates run `[sudo] gem install cocoapods --pre`
 
 ##### Enhancements
 
+* Integrate `swift_version` DSL support into pod targets  
+  [Dimitris Koutsogiorgas](https://github.com/dnkoutso)
+  [#7134](https://github.com/CocoaPods/CocoaPods/issues/7134)
+
 * Add color indication to output of `pod outdated`  
   [iv-mexx](https://github.com/iv-mexx)
   [#7204](https://github.com/CocoaPods/CocoaPods/pull/7204)

Gemfile.lock

@@ -7,7 +7,7 @@ GIT
 
 GIT
   remote: https://github.com/CocoaPods/Core.git
-  revision: 8cf88a076d916cf80821744a59ca1c431ccc046f
+  revision: 494334921393bfaed90fe97a224cabca14aad418
   branch: master
   specs:
     cocoapods-core (1.4.0.beta.2)

lib/cocoapods/target/pod_target.rb

@@ -95,10 +95,12 @@ module Pod
       end
     end
 
-    # @return [String] the Swift version for the target.
+    # @return [String] the Swift version for the target. If the pod author has provided a swift version
+    #                  then that is the one returned, otherwise the Swift version is determined by the user
+    #                  targets that include this pod target.
     #
     def swift_version
-      target_definitions.map(&:swift_version).compact.uniq.first
+      root_spec.swift_version || target_definitions.map(&:swift_version).compact.uniq.first
     end
 
     # @note   The deployment target for the pod target is the maximum of all

lib/cocoapods/validator.rb

@@ -257,8 +257,8 @@ module Pod
     #
     def swift_version
       return @swift_version unless @swift_version.nil?
-      if version = dot_swift_version
-        @swift_version = version
+      if (version = spec.swift_version) || (version = dot_swift_version)
+        @swift_version = version.to_s
       else
         DEFAULT_SWIFT_VERSION
       end
@@ -395,19 +395,37 @@ module Pod
 
     # Performs validation for which version of Swift is used during validation.
     #
+    # An error will be displayed if the user has provided a `swift_version` attribute within the podspec but is also
+    # using either  `--swift-version` parameter or a `.swift-version with a different Swift version.
+    #
     # The user will be warned that the default version of Swift was used if the following things are true:
     #   - The project uses Swift at all
     #   - The user did not supply a Swift version via a parameter
+    #   - There is no `swift_version` attribute set within the specification
     #   - There is no `.swift-version` file present either.
     #
     def validate_swift_version
-      if uses_swift? && @swift_version.nil? && dot_swift_version.nil?
-        warning(:swift_version,
+      return unless uses_swift?
+      spec_swift_version = spec.swift_version
+      unless spec_swift_version.nil?
+        message = nil
+        if !dot_swift_version.nil? && dot_swift_version != spec_swift_version.to_s
+          message = "Specification `#{spec.name}` specifies an inconsistent `swift_version` (`#{spec_swift_version}`) compared to the one present in your `.swift-version` file (`#{dot_swift_version}`). " \
+                    'Please remove the `.swift-version` file which is now deprecated and only use the `swift_version` attribute within your podspec.'
+        elsif !@swift_version.nil? && @swift_version != spec_swift_version.to_s
+          message = "Specification `#{spec.name}` specifies an inconsistent `swift_version` (`#{spec_swift_version}`) compared to the one passed during lint (`#{@swift_version}`)."
+        end
+        unless message.nil?
+          error('swift', message)
+          return
+        end
+      end
+      if @swift_version.nil? && spec_swift_version.nil? && dot_swift_version.nil?
+        warning('swift',
                 'The validator used ' \
                 "Swift #{DEFAULT_SWIFT_VERSION} by default because no Swift version was specified. " \
-                'If you want to use a different version of Swift during validation, then either use the `--swift-version` parameter ' \
-                'or use a `.swift-version` file to set the version of Swift to use for ' \
-                'your Pod. For example to use Swift 4.0, run: `echo "4.0" > .swift-version`.')
+                'To specify a Swift version during validation, add the `swift_version` attribute in your podspec. ' \
+                'Note that usage of the `--swift-version` parameter or a `.swift-version` file is now deprecated.')
       end
     end
 
@@ -471,12 +489,17 @@ module Pod
          perform_post_install_actions).each { |m| @installer.send(m) }
 
       deployment_target = spec.subspec_by_name(subspec_name).deployment_target(consumer.platform_name)
-      @installer.aggregate_targets.each do |target|
+      configure_pod_targets(@installer.aggregate_targets, deployment_target)
+      @installer.pods_project.save
+    end
+
+    def configure_pod_targets(targets, deployment_target)
+      targets.each do |target|
         target.pod_targets.each do |pod_target|
           next unless (native_target = pod_target.native_target)
           native_target.build_configuration_list.build_configurations.each do |build_configuration|
             (build_configuration.build_settings['OTHER_CFLAGS'] ||= '$(inherited)') << ' -Wincomplete-umbrella'
-            build_configuration.build_settings['SWIFT_VERSION'] = swift_version if pod_target.uses_swift?
+            build_configuration.build_settings['SWIFT_VERSION'] = (pod_target.swift_version || swift_version) if pod_target.uses_swift?
           end
           if pod_target.uses_swift?
             pod_target.test_native_targets.each do |test_native_target|
@@ -492,7 +515,6 @@ module Pod
           error('swift', 'Swift support uses dynamic frameworks and is therefore only supported on iOS > 8.') unless uses_xctest
         end
       end
-      @installer.pods_project.save
     end
 
     def validate_vendored_dynamic_frameworks

spec/unit/target/pod_target_spec.rb

@@ -144,6 +144,20 @@ module Pod
       end
     end
 
+    describe 'swift version' do
+      it 'uses the swift version defined in the specification' do
+        @pod_target.root_spec.stubs(:swift_version).returns('3.0')
+        @target_definition.stubs(:swift_version).returns('2.3')
+        @pod_target.swift_version.should == '3.0'
+      end
+
+      it 'uses the swift version defined by the target definitions if no swift version is specifed in the spec' do
+        @pod_target.root_spec.stubs(:swift_version).returns(nil)
+        @target_definition.stubs(:swift_version).returns('2.3')
+        @pod_target.swift_version.should == '2.3'
+      end
+    end
+
     describe 'Support files' do
       it 'returns the absolute path of the xcconfig file' do
         @pod_target.xcconfig_path('Release').to_s.should.include?(

spec/unit/validator_spec.rb

@@ -887,9 +887,55 @@ module Pod
           result.type.should == :warning
           result.message.should == 'The validator used ' \
             'Swift 3.2 by default because no Swift version was specified. ' \
-            'If you want to use a different version of Swift during validation, then either use the `--swift-version` parameter ' \
-            'or use a `.swift-version` file to set the version of Swift to use for ' \
-            'your Pod. For example to use Swift 4.0, run: `echo "4.0" > .swift-version`.'
+            'To specify a Swift version during validation, add the `swift_version` attribute in your podspec. ' \
+            'Note that usage of the `--swift-version` parameter or a `.swift-version` file is now deprecated.'
+        end
+
+        it 'errors when swift version spec attribute does not match dot swift version' do
+          Specification.any_instance.stubs(:deployment_target).returns('9.0')
+          Specification.any_instance.stubs(:swift_version).returns(Version.new('4.0'))
+
+          validator = test_swiftpod_with_dot_swift_version('3.2')
+          validator.validate
+          validator.results.count.should == 1
+
+          result = validator.results.first
+          result.type.should == :error
+          result.message.should == 'Specification `JSONKit` specifies an inconsistent `swift_version` (`4.0`) compared to the one present in your `.swift-version` file (`3.2`). ' \
+                                   'Please remove the `.swift-version` file which is now deprecated and only use the `swift_version` attribute within your podspec.'
+        end
+
+        it 'does not error when swift version spec attribute matches dot swift version' do
+          Specification.any_instance.stubs(:deployment_target).returns('9.0')
+          Specification.any_instance.stubs(:swift_version).returns(Version.new('4.0'))
+
+          validator = test_swiftpod_with_dot_swift_version('4.0')
+          validator.validate
+          validator.results.count.should == 0
+        end
+
+        it 'errors when swift version spec attribute does not match parameter based swift version' do
+          Specification.any_instance.stubs(:deployment_target).returns('9.0')
+          Specification.any_instance.stubs(:swift_version).returns(Version.new('4.0'))
+
+          validator = test_swiftpod
+          validator.swift_version = '3.2'
+          validator.validate
+          validator.results.count.should == 1
+
+          result = validator.results.first
+          result.type.should == :error
+          result.message.should == 'Specification `JSONKit` specifies an inconsistent `swift_version` (`4.0`) compared to the one passed during lint (`3.2`).'
+        end
+
+        it 'does not error when swift version spec attribute matches parameter based swift version' do
+          Specification.any_instance.stubs(:deployment_target).returns('9.0')
+          Specification.any_instance.stubs(:swift_version).returns(Version.new('4.0'))
+
+          validator = test_swiftpod
+          validator.swift_version = '4.0'
+          validator.validate
+          validator.results.count.should == 0
         end
 
         it 'does not warn for Swift if version was set by a dot swift version file' do
@@ -918,7 +964,13 @@ module Pod
           validator.swift_version.should == '3.2'
         end
 
-        it 'allows the user to set the version' do
+        it 'uses the Swift version specified by the swift_version attribute in the spec' do
+          validator = test_swiftpod
+          validator.spec.swift_version = '4.0'
+          validator.swift_version.should == '4.0'
+        end
+
+        it 'allows the user to set the Swift version using a .swift-version file' do
           validator = test_swiftpod
           validator.stubs(:dot_swift_version).returns('3.0')
           validator.swift_version = '4.0'
@@ -979,6 +1031,22 @@ module Pod
 
           validator.uses_swift?.should.be.false
         end
+
+        it 'honors swift version set by the pod target for dependencies' do
+          validator = test_swiftpod
+          consumer = stub(:platform_name => 'iOS')
+          validator.instance_variable_set(:@consumer, consumer)
+          debug_configuration_one = stub(:build_settings => {})
+          debug_configuration_two = stub(:build_settings => {})
+          native_target_one = stub(:build_configuration_list => stub(:build_configurations => [debug_configuration_one]))
+          native_target_two = stub(:build_configuration_list => stub(:build_configurations => [debug_configuration_two]))
+          pod_target_one = stub(:uses_swift? => true, :swift_version => '4.0', :native_target => native_target_one, :test_native_targets => [])
+          pod_target_two = stub(:uses_swift? => true, :swift_version => '3.2', :native_target => native_target_two, :test_native_targets => [])
+          aggregate_target = stub(:pod_targets => [pod_target_one, pod_target_two])
+          validator.send(:configure_pod_targets, [aggregate_target], '9.0')
+          debug_configuration_one.build_settings['SWIFT_VERSION'].should == '4.0'
+          debug_configuration_two.build_settings['SWIFT_VERSION'].should == '3.2'
+        end
       end
     end