Create unit tests for analyzer2dart/driver.

pkg/analyzer2dart/test/driver_test.dart

+// Copyright (c) 2014, 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 'package:analyzer/src/generated/element.dart';
+import 'package:analyzer/src/generated/source.dart';
+import 'package:unittest/unittest.dart';
+import 'package:analyzer/src/generated/ast.dart';
+
+import '../lib/src/closed_world.dart';
+import '../lib/src/driver.dart';
+
+main() {
+  test('setFakeRoot', () {
+    Driver driver = new Driver();
+    var contents = 'main() {}';
+    Source source = driver.setFakeRoot(contents);
+    expect(driver.context.getContents(source).data, equals(contents));
+  });
+
+  test('resolveEntryPoint', () {
+    Driver driver = new Driver();
+    String contents = 'main() {}';
+    FunctionElement element =
+        driver.resolveEntryPoint(driver.setFakeRoot(contents));
+    expect(element.name, equals('main'));
+  });
+
+  test('computeWorld', () {
+    Driver driver = new Driver();
+    String contents = '''
+main() {
+  foo();
+}
+
+foo() {
+}
+
+bar() {
+}
+''';
+    FunctionElement entryPoint = driver.resolveEntryPoint(driver.setFakeRoot(contents));

[Johnni Winther, 2014/08/28 11:25:28]

Long line.

+    ClosedWorld world =
+        driver.computeWorld(entryPoint);

[Johnni Winther, 2014/08/28 11:25:28]

This could fit in one line.

+    expect(world.elements, hasLength(2));
+    CompilationUnitElement compilationUnit = entryPoint.getAncestor((e) => e is CompilationUnitElement);

[Johnni Winther, 2014/08/28 11:25:29]

Ditto.

+    Map<String, FunctionElement> functions = {};
+    for (FunctionElement functionElement in compilationUnit.functions) {
+      functions[functionElement.name] = functionElement;
+    }
+    FunctionElement mainElement = functions['main'];
+    expect(world.elements.keys, contains(mainElement));
+    FunctionDeclaration mainAst = world.elements[mainElement];
+    expect(mainAst.element, equals(mainElement));
+    FunctionElement fooElement = functions['foo'];
+    expect(world.elements.keys, contains(fooElement));
+    FunctionDeclaration fooAst = world.elements[fooElement];
+    expect(fooAst.element, equals(fooElement));
+    FunctionElement barElement = functions['bar'];
+    expect(world.elements.keys, isNot(contains(functions[barElement])));
+  });
+}