1 files changed, 58 insertions, 0 deletions
diff --git a/app/services/projects/apple_target_platform_detector_service.rb b/app/services/projects/apple_target_platform_detector_service.rb
new file mode 100644
index 00000000000..ec4c16a1416
--- /dev/null
+++ b/app/services/projects/apple_target_platform_detector_service.rb
@@ -0,0 +1,58 @@
+# frozen_string_literal: true
+
+module Projects
+  # Service class to detect target platforms of a project made for the Apple
+  # Ecosystem.
+  #
+  # This service searches project.pbxproj and *.xcconfig files (contains build
+  # settings) for the string "SDKROOT = <SDK_name>" where SDK_name can be
+  # 'iphoneos', 'macosx', 'appletvos' or 'watchos'. Currently, the service is
+  # intentionally limited (for performance reasons) to detect if a project
+  # targets iOS.
+  #
+  # Ref: https://developer.apple.com/documentation/xcode/build-settings-reference/
+  #
+  # Example usage:
+  # > AppleTargetPlatformDetectorService.new(a_project).execute
+  # => []
+  # > AppleTargetPlatformDetectorService.new(an_ios_project).execute
+  # => [:ios]
+  # > AppleTargetPlatformDetectorService.new(multiplatform_project).execute
+  # => [:ios, :osx, :tvos, :watchos]
+  class AppleTargetPlatformDetectorService < BaseService
+    BUILD_CONFIG_FILENAMES = %w(project.pbxproj *.xcconfig).freeze
+
+    # For the current iteration, we only want to detect when the project targets
+    # iOS. In the future, we can use the same logic to detect projects that
+    # target OSX, TvOS, and WatchOS platforms with SDK names 'macosx', 'appletvos',
+    # and 'watchos', respectively.
+    PLATFORM_SDK_NAMES = { ios: 'iphoneos' }.freeze
+
+    def execute
+      detect_platforms
+    end
+
+    private
+
+    def file_finder
+      @file_finder ||= ::Gitlab::FileFinder.new(project, project.default_branch)
+    end
+
+    def detect_platforms
+      # Return array of SDK names for which "SDKROOT = <sdk_name>" setting
+      # definition can be found in either project.pbxproj or *.xcconfig files.
+      PLATFORM_SDK_NAMES.select do |_, sdk|
+        config_files_containing_sdk_setting(sdk).present?
+      end.keys
+    end
+
+    # Return array of project.pbxproj and/or *.xcconfig files
+    # (Gitlab::Search::FoundBlob) that contain the setting definition string
+    # "SDKROOT = <sdk_name>"
+    def config_files_containing_sdk_setting(sdk)
+      BUILD_CONFIG_FILENAMES.map do |filename|
+        file_finder.find("SDKROOT = #{sdk} filename:#{filename}")
+      end.flatten
+    end
+  end
+end