dvParseEnvContents function

Map<String, String> dvParseEnvContents(String contents)

Names and values from the contents of a .env file.

Blank lines and # comments are skipped. An export prefix is accepted, because people paste these files into a shell and a line the shell honours while the framework ignores it is a secret that is set everywhere except where the code goes looking. Matched quotes around a value are stripped.

KEY= is dropped rather than recorded as the empty string. That is what an unset variable looks like coming through a shell, and a payment client constructed with '' fails a long way from the cause.

Implementation

Map<String, String> dvParseEnvContents(String contents) {
  final Map<String, String> out = <String, String>{};
  for (final String raw in contents.split('\n')) {
    String line = raw.trim();
    if (line.isEmpty || line.startsWith('#')) continue;
    if (line.startsWith('export ')) line = line.substring(7).trim();

    final int separator = line.indexOf('=');
    if (separator <= 0) continue;

    final String name = line.substring(0, separator).trim();
    String value = line.substring(separator + 1).trim();
    if (value.length >= 2 &&
        ((value.startsWith('"') && value.endsWith('"')) ||
            (value.startsWith("'") && value.endsWith("'")))) {
      value = value.substring(1, value.length - 1);
    }
    if (value.isEmpty) continue;
    out[name] = value;
  }
  return out;
}