String? _createBinStub()

in lib/src/global_packages.dart [699:819]

• 100 lines of code
• 17 McCabe index (conditional complexity)

  String? _createBinStub(
    Package package,
    String executable,
    String script, {
    required bool overwrite,
    required String snapshot,
  }) {
    var binStubPath = p.join(_binStubDir, executable);
    if (Platform.isWindows) binStubPath += '.bat';

    // See if the binstub already exists. If so, it's for another package
    // since we already deleted all of this package's binstubs.
    String? previousPackage;
    if (fileExists(binStubPath)) {
      var contents = readTextFile(binStubPath);
      previousPackage = _binStubProperty(contents, 'Package');
      if (previousPackage == null) {
        log.fine('Could not parse binstub $binStubPath:\n$contents');
      } else if (!overwrite) {
        return previousPackage;
      }
    }

    // If the script was built to a snapshot, just try to invoke that
    // directly and skip pub global run entirely.
    String invocation;
    late String binstub;
    if (Platform.isWindows) {
      if (fileExists(snapshot)) {
        // We expect absolute paths from the precompiler since relative ones
        // won't be relative to the right directory when the user runs this.
        assert(p.isAbsolute(snapshot));
        invocation = '''
if exist "$snapshot" (
  call dart "$snapshot" %*
  rem The VM exits with code 253 if the snapshot version is out-of-date.
  rem If it is, we need to delete it and run "pub global" manually.
  if not errorlevel 253 (
    goto error
  )
  dart pub global run ${package.name}:$script %*
) else (
  dart pub global run ${package.name}:$script %*
)
goto eof
:error
exit /b %errorlevel%
:eof
''';
      } else {
        invocation = 'dart pub global run ${package.name}:$script %*';
      }
      binstub = '''
@echo off
rem This file was created by pub v${sdk.version}.
rem Package: ${package.name}
rem Version: ${package.version}
rem Executable: $executable
rem Script: $script
$invocation
''';
    } else {
      if (fileExists(snapshot)) {
        // We expect absolute paths from the precompiler since relative ones
        // won't be relative to the right directory when the user runs this.
        assert(p.isAbsolute(snapshot));
        invocation = '''
if [ -f $snapshot ]; then
  dart "$snapshot" "\$@"
  # The VM exits with code 253 if the snapshot version is out-of-date.	
  # If it is, we need to delete it and run "pub global" manually.	
  exit_code=\$?	
  if [ \$exit_code != 253 ]; then	
    exit \$exit_code	
  fi	
  dart pub global run ${package.name}:$script "\$@"
else
  dart pub global run ${package.name}:$script "\$@"
fi
''';
      } else {
        invocation = 'dart pub global run ${package.name}:$script "\$@"';
      }
      binstub = '''
#!/usr/bin/env sh
# This file was created by pub v${sdk.version}.
# Package: ${package.name}
# Version: ${package.version}
# Executable: $executable
# Script: $script
$invocation
''';
    }

    // Write the binstub to a temporary location, make it executable and move
    // it into place afterwards to avoid races.
    final tempDir = cache.createTempDir();
    try {
      final tmpPath = p.join(tempDir, binStubPath);

      // Write this as the system encoding since the system is going to
      // execute it and it might contain non-ASCII characters in the
      // pathnames.
      writeTextFile(tmpPath, binstub, encoding: const SystemEncoding());

      if (Platform.isLinux || Platform.isMacOS) {
        // Make it executable.
        var result = Process.runSync('chmod', ['+x', tmpPath]);
        if (result.exitCode != 0) {
          // Couldn't make it executable so don't leave it laying around.
          fail('Could not make "$tmpPath" executable (exit code '
              '${result.exitCode}):\n${result.stderr}');
        }
      }
      File(tmpPath).renameSync(binStubPath);
    } finally {
      deleteEntry(tempDir);
    }

    return previousPackage;
  }