[action][spm] add parallel option

fastlane/lib/fastlane/actions/spm.rb

@@ -12,6 +12,7 @@ def self.run(params)
         cmd << "--verbose" if params[:verbose]
         cmd << params[:command] if package_commands.include?(params[:command])
         cmd << "--enable-code-coverage" if params[:enable_code_coverage] && (params[:command] == 'generate-xcodeproj' || params[:command] == 'test')
+        cmd << "--parallel" if params[:parallel] && params[:command] == 'test'
         if params[:xcconfig]
           cmd << "--xcconfig-overrides #{params[:xcconfig]}"
         end
@@ -50,6 +51,11 @@ def self.available_options
                                        description: "Enables code coverage for the generated Xcode project when using the 'generate-xcodeproj' and the 'test' command",
                                        type: Boolean,
                                        optional: true),
+          FastlaneCore::ConfigItem.new(key: :parallel,
+                                       env_name: "FL_SPM_PARALLEL",
+                                       description: "Enables running tests in parallel when using the 'test' command",
+                                       type: Boolean,
+                                       optional: true),
           FastlaneCore::ConfigItem.new(key: :build_path,
                                        env_name: "FL_SPM_BUILD_PATH",
                                        description: "Specify build/cache directory [default: ./.build]",

fastlane/spec/actions_specs/spm_spec.rb

@@ -186,6 +186,48 @@
 
           expect(result).to eq("swift test")
         end
+
+        it "sets --parallel to true for test" do
+          result = Fastlane::FastFile.new.parse("lane :test do
+            spm(
+              command: 'test',
+              parallel: true
+            )
+          end").runner.execute(:test)
+
+          expect(result).to eq("swift test --parallel")
+        end
+
+        it "sets --parellel to false for test" do
+          result = Fastlane::FastFile.new.parse("lane :test do
+            spm(
+              command: 'test',
+              parallel: false
+            )
+          end").runner.execute(:test)
+
+          expect(result).to eq("swift test")
+        end
+
+        it "does not add --parellel by default" do
+          result = Fastlane::FastFile.new.parse("lane :test do
+            spm(
+              command: 'test'
+            )
+          end").runner.execute(:test)
+
+          expect(result).to eq("swift test")
+        end
+
+        it "does not add --parellel for irrelevant commands" do
+          result = Fastlane::FastFile.new.parse("lane :test do
+            spm(
+              parallel: true
+            )
+          end").runner.execute(:test)
+
+          expect(result).to eq("swift build")
+        end
       end
 
       context "when command is package related" do