Add Firefox extension web-ext targets

scripts/prepare_firefox_extension.py

@@ -0,0 +1,29 @@
+#!/usr/bin/env python3
+
+import argparse
+import json
+import shutil
+from pathlib import Path
+
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+SOURCE_DIR = REPO_ROOT / "browser" / "extension"
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(description="Prepare a Firefox extension directory for web-ext.")
+    parser.add_argument("output_dir", help="directory to write the prepared extension into")
+    args = parser.parse_args()
+
+    output_dir = Path(args.output_dir).resolve()
+    if output_dir.exists():
+        shutil.rmtree(output_dir)
+    shutil.copytree(SOURCE_DIR, output_dir)
+
+    manifest = json.loads((output_dir / "manifest.firefox.json").read_text(encoding="utf-8"))
+    (output_dir / "manifest.json").write_text(json.dumps(manifest, indent=2) + "\n", encoding="utf-8")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())