build/dart/gen_app_invocation.py

#!/usr/bin/env fuchsia-vendored-python
# Copyright 2017 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import argparse
import os
import stat
import string
import sys


def main():
    parser = argparse.ArgumentParser(
        description="Generate a script that invokes a Dart application"
    )
    parser.add_argument(
        "--out", help="Path to the invocation file to generate", required=True
    )
    parser.add_argument("--dart", help="Path to the Dart binary", required=True)
    parser.add_argument(
        "--snapshot", help="Path to the app snapshot", required=True
    )
    args = parser.parse_args()

    app_file = args.out
    app_path = os.path.dirname(app_file)
    if not os.path.exists(app_path):
        os.makedirs(app_path)

    # `dart` and `snapshot` are used in the output app script, use relative path
    # from script directory so it works from wherever it is invoked.
    rel_dart = os.path.relpath(args.dart, app_path)
    rel_snapshot = os.path.relpath(args.snapshot, app_path)

    script_content = f"""#!/bin/bash
SCRIPT_DIR="$(cd "$(dirname "${{BASH_SOURCE[0]}}")" >/dev/null 2>&1 && pwd)"
$SCRIPT_DIR/{rel_dart} \\
  $SCRIPT_DIR/{rel_snapshot} \\
  "$@"
"""
    with open(app_file, "w") as file:
        file.write(script_content)
    permissions = (
        stat.S_IRUSR
        | stat.S_IWUSR
        | stat.S_IXUSR
        | stat.S_IRGRP
        | stat.S_IWGRP
        | stat.S_IXGRP
        | stat.S_IROTH
    )
    os.chmod(app_file, permissions)


if __name__ == "__main__":
    sys.exit(main())