blob: 2ade49d67e0147f7b0405f2d8d0e4e58ccd35216 [file] [log] [blame]
// Copyright 2020 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 'dart:io';
/// Wraps [Platform] for the sake of mocking env results in tests.
/// For now, this class only has a pass-thru to [Platform.environment]
/// since that's all that's currently needed, but in theory it may be nice to
/// use this to test all sorts of platform-related checks we might make.
/// Note that, for now, this is unnecessary if there is actually a way to mock
/// environment variables on a per-test basis, but after some research, I am
/// unaware of any such trick.
/// Usage:
/// ```dart
/// final envReader = EnvReader(environment: Platform.environment);
/// String envVariableValue = envReader.getEnv('MY_ENV_VAR');
/// ```
class EnvReader {
final String cwd;
final Map<String, String> environment;
final Map<String, String> overrides;
required this.environment,
required this.cwd,
this.overrides = const {},
factory EnvReader.fromEnvironment() =>
EnvReader(environment: Platform.environment, cwd: Directory.current.path);
String? getEnv(String variableName, [String? defaultValue]) {
// print('asking for $variableName with overrides: $overrides');
// print('asking for $variableName with environment: $environment');
return overrides[variableName] ?? environment[variableName] ?? defaultValue;
String getCwd() => overrides['cwd'] ?? cwd;