Merge pull request #238 from ably/code-coverage

[ECO-5252] Generate a code coverage report in CI

Author: lawrence-forooghian

.github/workflows/check.yaml

@@ -138,6 +138,41 @@ jobs:
       - name: Run tests
         run: swift run BuildTool test-library --platform ${{ matrix.platform }}
 
+  code-coverage:
+    name: Generate code coverage (Xcode ${{ matrix.tooling.xcodeVersion }})
+    runs-on: macos-15
+    needs: generate-matrices
+    strategy:
+      fail-fast: false
+      matrix: ${{ fromJson(needs.generate-matrices.outputs.matrix).withoutPlatform }}
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: true
+      - uses: maxim-lobanov/setup-xcode@v1
+        with:
+          xcode-version: ${{ matrix.tooling.xcodeVersion }}
+
+      - run: swift run BuildTool generate-code-coverage --result-bundle-path CodeCoverage.xcresult
+
+      # Generate a Markdown report of the code coverage information and add it to the workflow run.
+      #
+      # This tool is the best option that I could find after a brief look at the options. There are a few things that I wish it could do:
+      #
+      # - post a message on the pull request, like they do on Kotlin
+      # - offer more fine-grained configuration about which data to include in the report (I only care about code coverage, not test results, and I don't care about code coverage of the AblyChatTests target)
+      #
+      # but it'll do for now (we can always fork or have another look for tooling later).
+      - uses: slidoapp/xcresulttool@v3.1.0
+        with:
+          path: CodeCoverage.xcresult
+          # This title will be used for the sidebar item that this job adds to GitHub results page for this workflow
+          title: Code coverage results
+          # Turning off as much non-code-coverage information as it lets me
+          show-passed-tests: false
+        if: success() || failure()
+
   build-release-configuration-xcode:
     name: Xcode, `release` configuration, ${{matrix.platform}} (Xcode ${{ matrix.tooling.xcodeVersion }})
     runs-on: macos-15
@@ -247,6 +282,7 @@ jobs:
       - build-release-configuration-xcode
       - check-example-app
       - check-documentation
+      - code-coverage
 
     steps:
       - name: No-op

Sources/BuildTool/BuildTool.swift

@@ -16,6 +16,7 @@ struct BuildTool: AsyncParsableCommand {
             Lint.self,
             SpecCoverage.self,
             BuildDocumentation.self,
+            GenerateCodeCoverage.self,
         ]
     )
 }
@@ -71,6 +72,31 @@ struct TestLibrary: AsyncParsableCommand {
     }
 }
 
+@available(macOS 14, *)
+struct GenerateCodeCoverage: AsyncParsableCommand {
+    static let configuration = CommandConfiguration(
+        abstract: "Generate code coverage for the AblyChat library",
+        discussion: "Runs the unit tests and outputs a .xcresult bundle containing code coverage information"
+    )
+
+    @Option(help: "Pathname of where to output the .xcresult bundle.")
+    var resultBundlePath: String
+
+    mutating func run() async throws {
+        let platform = Platform.macOS
+        let destinationSpecifier = try await platform.resolve()
+        let scheme = "AblyChat"
+
+        try await XcodeRunner.runXcodebuild(
+            action: "test",
+            scheme: scheme,
+            destination: destinationSpecifier,
+            testPlan: "UnitTests",
+            resultBundlePath: resultBundlePath
+        )
+    }
+}
+
 @available(macOS 14, *)
 struct BuildExampleApp: AsyncParsableCommand {
     static let configuration = CommandConfiguration(abstract: "Build the AblyChatExample example app")

Sources/BuildTool/XcodeRunner.swift

@@ -2,7 +2,7 @@ import Foundation
 
 @available(macOS 14, *)
 enum XcodeRunner {
-    static func runXcodebuild(action: String?, configuration: Configuration? = nil, scheme: String, destination: DestinationSpecifier) async throws {
+    static func runXcodebuild(action: String?, configuration: Configuration? = nil, scheme: String, destination: DestinationSpecifier, testPlan: String? = nil, resultBundlePath: String? = nil) async throws {
         var arguments: [String] = []
 
         if let action {
@@ -16,6 +16,14 @@ enum XcodeRunner {
         arguments.append(contentsOf: ["-scheme", scheme])
         arguments.append(contentsOf: ["-destination", destination.xcodebuildArgument])
 
+        if let testPlan {
+            arguments.append(contentsOf: ["-testPlan", testPlan])
+        }
+
+        if let resultBundlePath {
+            arguments.append(contentsOf: ["-resultBundlePath", resultBundlePath])
+        }
+
         /*
          Note: I was previously passing SWIFT_TREAT_WARNINGS_AS_ERRORS=YES here, but am no longer able to do so, for the following reasons: