Only check for valid Swift version for pod targets that use Swift

CHANGELOG.md

@@ -18,6 +18,10 @@ To install release candidates run `[sudo] gem install cocoapods --pre`
 
 ##### Bug Fixes
 
+* Only check for valid Swift version for pod targets that use Swift  
+  [Dimitris Koutsogiorgas](https://github.com/dnkoutso)
+  [#6733](https://github.com/CocoaPods/CocoaPods/pull/6733) 
+
 * Fix pod install error from 1.2.1 when working with static lib-only projects.  
   [Ben Asher](https://github.com/benasher44)
   [#6673](https://github.com/CocoaPods/CocoaPods/issues/6673)

lib/cocoapods/installer/analyzer.rb

@@ -367,7 +367,6 @@ module Pod
       #
       def generate_targets
         specs_by_target = result.specs_by_target.reject { |td, _| td.abstract? }
-        check_pod_target_swift_versions(specs_by_target)
         pod_targets = generate_pod_targets(specs_by_target)
         aggregate_targets = specs_by_target.keys.map do |target_definition|
           generate_target(target_definition, pod_targets)
@@ -435,39 +434,6 @@ module Pod
         target
       end
 
-      # Verify that targets using a pod have the same swift version
-      #
-      # @param  [Hash{Podfile::TargetDefinition => Array<Specification>}] specs_by_target
-      #         the resolved specifications grouped by target.
-      #
-      # @note raises Informative if targets using a pod do not have
-      #       the same swift version
-      #
-      def check_pod_target_swift_versions(specs_by_target)
-        targets_by_spec = {}
-        specs_by_target.each do |target, specs|
-          specs.each do |spec|
-            (targets_by_spec[spec] ||= []) << target
-          end
-        end
-
-        error_message_for_target = lambda do |target|
-          "#{target.name} (Swift #{target.swift_version})"
-        end
-
-        error_messages = targets_by_spec.map do |spec, targets|
-          swift_targets = targets.reject { |target| target.swift_version.blank? }
-          next if swift_targets.empty? || swift_targets.uniq(&:swift_version).count == 1
-          target_errors = swift_targets.map(&error_message_for_target).join(', ')
-          "- #{spec.name} required by #{target_errors}"
-        end.compact
-
-        unless error_messages.empty?
-          raise Informative, 'The following pods are integrated into targets ' \
-            "that do not have the same Swift version:\n\n#{error_messages.join("\n")}"
-        end
-      end
-
       # Setup the pod targets for an aggregate target. Deduplicates resulting
       # targets by grouping by platform and subspec by their root
       # to create a {PodTarget} for each spec.

lib/cocoapods/installer/xcode/target_validator.rb

@@ -34,6 +34,7 @@ module Pod
         def validate!
           verify_no_duplicate_framework_and_library_names
           verify_no_static_framework_transitive_dependencies
+          verify_no_pods_used_with_multiple_swift_versions
           verify_framework_usage
         end
 
@@ -84,6 +85,24 @@ module Pod
           end
         end
 
+        def verify_no_pods_used_with_multiple_swift_versions
+          error_message_for_target = lambda do |target|
+            "#{target.name} (Swift #{target.swift_version})"
+          end
+          swift_pod_targets = pod_targets.select(&:uses_swift?)
+          error_messages = swift_pod_targets.map do |pod_target|
+            swift_target_definitions = pod_target.target_definitions.reject { |target| target.swift_version.blank? }
+            next if swift_target_definitions.empty? || swift_target_definitions.uniq(&:swift_version).count == 1
+            target_errors = swift_target_definitions.map(&error_message_for_target).join(', ')
+            "- #{pod_target.name} required by #{target_errors}"
+          end.compact
+
+          unless error_messages.empty?
+            raise Informative, 'The following pods are integrated into targets ' \
+            "that do not have the same Swift version:\n\n#{error_messages.join("\n")}"
+          end
+        end
+
         def verify_framework_usage
           aggregate_targets.each do |aggregate_target|
             next if aggregate_target.requires_frameworks?

spec/unit/installer/analyzer_spec.rb

@@ -662,40 +662,6 @@ module Pod
         should.raise(Informative) { analyzer.analyze }
       end
 
-      it 'raises when targets integrate the same swift pod but have different swift versions' do
-        podfile = Podfile.new do
-          source SpecHelper.test_repo_url
-          project 'SampleProject/SampleProject'
-          platform :ios, '8.0'
-          pod 'OrangeFramework'
-          target 'SampleProject'
-          target 'TestRunner'
-        end
-        podfile.target_definitions['SampleProject'].stubs(:swift_version).returns('3.0')
-        podfile.target_definitions['TestRunner'].stubs(:swift_version).returns('2.3')
-        analyzer = Pod::Installer::Analyzer.new(config.sandbox, podfile)
-
-        should.raise Informative do
-          analyzer.analyze
-        end.message.should.match /The following pods are integrated into targets that do not have the same Swift version:/
-      end
-
-      it 'does not raise when targets integrate the same pod but only one of the targets is a swift target' do
-        podfile = Podfile.new do
-          source SpecHelper.test_repo_url
-          project 'SampleProject/SampleProject'
-          platform :ios, '8.0'
-          pod 'OrangeFramework'
-          target 'SampleProject'
-          target 'TestRunner'
-        end
-        podfile.target_definitions['SampleProject'].stubs(:swift_version).returns('3.0')
-        # when the swift version is unset at the project level, but set in one target, swift_version is nil
-        podfile.target_definitions['TestRunner'].stubs(:swift_version).returns(nil)
-        analyzer = Pod::Installer::Analyzer.new(config.sandbox, podfile)
-        lambda { analyzer.analyze }.should.not.raise
-      end
-
       #--------------------------------------#
 
       it 'computes the state of the Sandbox respect to the resolved dependencies' do

spec/unit/installer/xcode/target_validator_spec.rb

@@ -143,6 +143,86 @@ module Pod
 
         #-------------------------------------------------------------------------#
 
+        describe '#verify_no_pods_used_with_multiple_swift_versions' do
+          it 'raises when targets integrate the same swift pod but have different swift versions' do
+            fixture_path = ROOT + 'spec/fixtures'
+            config.repos_dir = fixture_path + 'spec-repos'
+            podfile = Podfile.new do
+              project 'SampleProject/SampleProject'
+              platform :ios, '8.0'
+              use_frameworks!
+              pod 'OrangeFramework', :path => (fixture_path + 'orange-framework').to_s
+              pod 'matryoshka',      :path => (fixture_path + 'matryoshka').to_s
+              target 'SampleProject'
+              target 'TestRunner'
+            end
+
+            podfile.target_definitions['SampleProject'].stubs(:swift_version).returns('3.0')
+            podfile.target_definitions['TestRunner'].stubs(:swift_version).returns('2.3')
+
+            orangeframework_pod_target = stub(:name => 'OrangeFramework', :uses_swift? => true, :target_definitions => [podfile.target_definitions['SampleProject'], podfile.target_definitions['TestRunner']])
+            matryoshka_pod_target = stub(:name => 'matryoshka', :uses_swift? => false, :target_definitions => [podfile.target_definitions['SampleProject'], podfile.target_definitions['TestRunner']])
+
+            @validator = TargetValidator.new([], [orangeframework_pod_target, matryoshka_pod_target])
+            e = should.raise Informative do
+              @validator.validate!
+            end
+            e.message.should.match /The following pods are integrated into targets that do not have the same Swift version:/
+            e.message.should.include 'OrangeFramework required by SampleProject (Swift 3.0), TestRunner (Swift 2.3)'
+            e.message.should.not.include 'matryoshka required by SampleProject (Swift 3.0), TestRunner (Swift 2.3)'
+          end
+
+          it 'does not raise when targets integrate the same pod but only one of the targets is a swift target' do
+            fixture_path = ROOT + 'spec/fixtures'
+            config.repos_dir = fixture_path + 'spec-repos'
+            podfile = Podfile.new do
+              project 'SampleProject/SampleProject'
+              use_frameworks!
+              platform :ios, '8.0'
+              pod 'OrangeFramework', :path => (fixture_path + 'orange-framework').to_s
+              pod 'matryoshka',      :path => (fixture_path + 'matryoshka').to_s
+              target 'SampleProject'
+              target 'TestRunner'
+            end
+
+            podfile.target_definitions['SampleProject'].stubs(:swift_version).returns('3.0')
+            # when the swift version is unset at the project level, but set in one target, swift_version is nil
+            podfile.target_definitions['TestRunner'].stubs(:swift_version).returns(nil)
+
+            orangeframework_pod_target = stub(:name => 'OrangeFramework', :uses_swift? => true, :target_definitions => [podfile.target_definitions['SampleProject'], podfile.target_definitions['TestRunner']])
+            matryoshka_pod_target = stub(:name => 'matryoshka', :uses_swift? => true, :target_definitions => [podfile.target_definitions['SampleProject'], podfile.target_definitions['TestRunner']])
+
+            @validator = TargetValidator.new([], [orangeframework_pod_target, matryoshka_pod_target])
+            lambda { @validator.validate! }.should.not.raise
+          end
+
+          it 'does not raise when targets integrate the same pod but none of the pod targets use swift' do
+            fixture_path = ROOT + 'spec/fixtures'
+            config.repos_dir = fixture_path + 'spec-repos'
+            podfile = Podfile.new do
+              project 'SampleProject/SampleProject'
+              use_frameworks!
+              platform :ios, '8.0'
+              pod 'OrangeFramework', :path => (fixture_path + 'orange-framework').to_s
+              pod 'matryoshka',      :path => (fixture_path + 'matryoshka').to_s
+              target 'SampleProject'
+              target 'TestRunner'
+            end
+
+            podfile.target_definitions['SampleProject'].stubs(:swift_version).returns('3.0')
+            podfile.target_definitions['TestRunner'].stubs(:swift_version).returns('2.3')
+
+            # Pretend none of the pod targets use swift, even if the target definitions they are linked with do have different Swift versions.
+            orangeframework_pod_target = stub(:name => 'OrangeFramework', :uses_swift? => false, :target_definitions => [podfile.target_definitions['SampleProject'], podfile.target_definitions['TestRunner']])
+            matryoshka_pod_target = stub(:name => 'matryoshka', :uses_swift? => false, :target_definitions => [podfile.target_definitions['SampleProject'], podfile.target_definitions['TestRunner']])
+
+            @validator = TargetValidator.new([], [orangeframework_pod_target, matryoshka_pod_target])
+            lambda { @validator.validate! }.should.not.raise
+          end
+        end
+
+        #-------------------------------------------------------------------------#
+
         describe '#verify_framework_usage' do
           it 'raises when Swift pods are used without explicit `use_frameworks!`' do
             fixture_path = ROOT + 'spec/fixtures'