Implement fromEnvironment on bool, int and String

tests/standalone/from_environment_test.dart

+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. 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:convert';
+import 'dart:io';
+
+import "package:expect/expect.dart";
+import 'package:path/path.dart';
+
+Future test(List defines, String script, Map expected, {bool fail: false}) {
+  String executable = new File(Platform.executable).fullPathSync();
+  var script_path = join(dirname(Platform.script), script);
+  var args = [];
+  args.addAll(defines);
+  args.add(script_path);
+  print(args);
+  Map fromEnviromnemt;
+  return Process.run(executable, args)
+    .then((result) {
+      print(result.stderr);
+      if (!fail) {
+        Expect.equals(0, result.exitCode);
+        print(result.stdout);
+        fromEnviromnemt = JSON.decode(result.stdout);
+        expected.forEach((key, value) {
+            Expect.equals(value, fromEnviromnemt[key]);
+          });
+      } else {
+        print(result.exitCode);
+        print(result.stdout);
+        Expect.isFalse(result.exitCode == 0);
+      }
+    });
+}
+
+main() {
+  //String tests.
+  test(['-Da=a', '-Db=bb', '-Dc=ccc'],
+       'from_environment_string_script.dart',
+       {'a' : 'a', 'b' : 'bb', 'c': 'ccc'})
+  .then((_) {
+  test(['-Da=a'],
+       'from_environment_string_script.dart',
+       {'a' : 'a', 'b' : '', 'c': 'default'});
+  })
+  .then((_) {
+  test(['-Da=1', '-Db=12', '-Dc=123'],
+       'from_environment_int_script.dart',
+       {'a' : 1, 'b' : 12, 'c': 123});
+  })
+  // Integer tests.
+  .then((_) {
+  test(['-Da=1', '-Db=12', '-Dc=123'],
+       'from_environment_int_script.dart',
+       {'a' : 1, 'b' : 12, 'c': 123});
+  })
+  // Boolean tests.
+  .then((_) {
+  test(['-Da=true', '-Db=false', '-Dc=yes'],
+       'from_environment_bool_script.dart',
+       {'a' : true, 'b' : false, 'c': true});
+  })
+  .then((_) {
+  test(['-Da=0', '-Db=false', '-Dc'],
+       'from_environment_bool_script.dart',
+       {'a' : true, 'b' : false, 'c': true});
+  })
+  .then((_) {
+  test(['-Da=a'],
+       'from_environment_bool_script.dart',
+       {'a' : true, 'b' : false, 'c': true});
+  })
+  // Failing tests
+  .then((_) {
+  test(['-Da'],
+       'from_environment_string_script.dart',
+       null,
+       fail: true);
+  })
+  .then((_) {
+  test(['-Da'],
+       'from_environment_int_script.dart',
+       null,
+       fail: true);
+  })
+  .then((_) {
+  test(['-Db=12', '-Dc=13'],
+       'from_environment_bool_script.dart',
+       null,
+       fail: true);
+  });
+}