Add support for 'dart.library.X' environment variables in dart2js.

tests/compiler/dart2js/library_env_test.dart

+// Copyright (c) 2015, 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.
+
+/// Check that 'dart:' libraries have their corresponding dart.library.X
+/// environment variable set.
+
+import "dart:io";
+
+import "dart:async";
+
+import "memory_source_file_helper.dart";
+
+import "package:async_helper/async_helper.dart";
+
+import 'package:expect/expect.dart' show
+    Expect;
+
+import 'package:compiler/src/elements/elements.dart' show
+    LibraryElement;
+
+import 'package:compiler/src/null_compiler_output.dart' show
+    NullCompilerOutput;
+
+import 'package:compiler/compiler_new.dart' show
+    CompilerInput,
+    CompilerDiagnostics;
+
+import 'package:sdk_library_metadata/libraries.dart' show
+    DART2JS_PLATFORM,
+    LibraryInfo;
+
+const LibraryInfo mock1LibraryInfo = const LibraryInfo(
+    "mock1.dart",
+    category: "Client",
+    documented: false,
+    platforms: DART2JS_PLATFORM);
+
+const LibraryInfo mock2LibraryInfo = const LibraryInfo(
+    "mock2.dart",
+    category: "Server",
+    documented: false,
+    platforms: DART2JS_PLATFORM);
+
+const LibraryInfo mock3LibraryInfo = const LibraryInfo(
+    "mock3.dart",
+    category: "Shared",
+    documented: false,
+    platforms: DART2JS_PLATFORM);
+
+class DummyCompilerInput implements CompilerInput {
+  const DummyCompilerInput();
+
+  readFromUri(uri) {
+    throw "should not be needed";
+  }
+}
+
+class DummyCompilerDiagnostics implements CompilerDiagnostics {
+  const DummyCompilerDiagnostics();
+
+  report(code, uri, begin, end, text, kind) {
+    throw "should not be needed";
+  }
+}
+
+class CustomCompiler extends Compiler {
+  CustomCompiler(
+      options,
+      environment)
+      : super(
+          const DummyCompilerInput(),
+          const NullCompilerOutput(),
+          const DummyCompilerDiagnostics(),
+          Uri.base.resolve("sdk/"),
+          null,
+          options,
+          environment);
+
+  LibraryInfo lookupLibraryInfo(String name) {
+    if (name == "mock.client") return mock1LibraryInfo;
+    if (name == "mock.server") return mock2LibraryInfo;
+    if (name == "mock.shared") return mock3LibraryInfo;
+    return super.lookupLibraryInfo(name);
+  }
+}
+
+main() {
+  Compiler compiler = new CustomCompiler(
+      [],
+      {});
+
+  // Core libraries are always present.
+  Expect.equals("true", compiler.fromEnvironment("dart.library.collection"));
+  // Non-existing entries in the environment return 'null'.
+  Expect.isNull(compiler.fromEnvironment("not in env"));
+  // Check for client libraries (default if there are no flags to the compiler).
+  Expect.equals("true", compiler.fromEnvironment("dart.library.mock.client"));
+  Expect.equals("true", compiler.fromEnvironment("dart.library.html"));
+  // Check for shared libraries..
+  Expect.equals("true", compiler.fromEnvironment("dart.library.mock.shared"));
+  // Check server libraries are not present.
+  Expect.equals(null, compiler.fromEnvironment("dart.library.mock.server"));
+  Expect.equals(null, compiler.fromEnvironment("dart.library.io"));
+
+  compiler = new CustomCompiler(
+      ['--categories=Server'],
+      {});
+
+  // Core libraries are always present.
+  Expect.equals("true", compiler.fromEnvironment("dart.library.collection"));
+  // Non-existing entries in the environment return 'null'.
+  Expect.isNull(compiler.fromEnvironment("not in env"));
+  // Check client libraries are not present.
+  Expect.equals(null, compiler.fromEnvironment("dart.library.mock.client"));
+  Expect.equals(null, compiler.fromEnvironment("dart.library.html"));
+  // Check for shared libraries..
+  Expect.equals("true", compiler.fromEnvironment("dart.library.mock.shared"));
+  // Check for server libraries.
+  Expect.equals("true", compiler.fromEnvironment("dart.library.mock.server"));
+  Expect.equals("true", compiler.fromEnvironment("dart.library.io"));
+
+  // Check that user-defined env-variables win.
+  compiler = new CustomCompiler(
+      [],
+      {'dart.library.collection': "false",
+       'dart.library.mock.client': "foo"});
+  Expect.equals("false", compiler.fromEnvironment("dart.library.collection"));
+  Expect.equals("foo", compiler.fromEnvironment("dart.library.mock.client"));
+}