feat: add macos screencapturekit helper

scripts/build-macos-screencapturekit-helper.mjs

@@ -1,13 +1,75 @@
 #!/usr/bin/env node
 
+import { spawnSync } from "node:child_process";
+import fs from "node:fs";
+import path from "node:path";
 import process from "node:process";
+import { fileURLToPath } from "node:url";
 
 if (process.platform !== "darwin") {
 	console.log("Skipping macOS ScreenCaptureKit helper build: host platform is not macOS.");
 	process.exit(0);
 }
 
-console.error(
-	"macOS ScreenCaptureKit helper sources are not implemented yet. See docs/engineering/macos-native-recorder-roadmap.md.",
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const root = path.resolve(__dirname, "..");
+const helperName = "openscreen-screencapturekit-helper";
+const packageDir = path.join(root, "electron", "native", "screencapturekit");
+const buildDir = path.join(packageDir, "build");
+const swiftBuildDir = path.join(buildDir, "swiftpm");
+const builtHelperPath = path.join(swiftBuildDir, "release", helperName);
+const localHelperPath = path.join(buildDir, helperName);
+const archTag = process.arch === "arm64" ? "darwin-arm64" : "darwin-x64";
+const distributableDir = path.join(root, "electron", "native", "bin", archTag);
+const distributablePath = path.join(distributableDir, helperName);
+
+const xcodebuildVersion = spawnSync("xcodebuild", ["-version"], {
+	cwd: root,
+	encoding: "utf8",
+});
+
+if (xcodebuildVersion.status !== 0) {
+	const message = `${xcodebuildVersion.stderr ?? ""}${xcodebuildVersion.stdout ?? ""}`.trim();
+	console.error(
+		[
+			"Unable to build the macOS ScreenCaptureKit helper because full Xcode is not active.",
+			"",
+			message,
+			"",
+			"Install Xcode from the App Store or Apple Developer downloads, then run:",
+			"  sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer",
+			"  sudo xcodebuild -license accept",
+			"",
+			"Command Line Tools alone may not include the Swift SDK/platform metadata required by SwiftPM.",
+		].join("\n"),
+	);
+	process.exit(1);
+}
+
+const result = spawnSync(
+	"swift",
+	["build", "-c", "release", "--package-path", packageDir, "--build-path", swiftBuildDir],
+	{
+		cwd: root,
+		stdio: "inherit",
+	},
 );
-process.exit(1);
+
+if (result.error) {
+	console.error(`Failed to start Swift build: ${result.error.message}`);
+	process.exit(1);
+}
+
+if (result.status !== 0) {
+	process.exit(result.status ?? 1);
+}
+
+fs.mkdirSync(buildDir, { recursive: true });
+fs.mkdirSync(distributableDir, { recursive: true });
+fs.copyFileSync(builtHelperPath, localHelperPath);
+fs.copyFileSync(builtHelperPath, distributablePath);
+fs.chmodSync(localHelperPath, 0o755);
+fs.chmodSync(distributablePath, 0o755);
+
+console.log(`Built macOS ScreenCaptureKit helper: ${localHelperPath}`);
+console.log(`Copied redistributable helper: ${distributablePath}`);