Add js_interface_generator for generating extensions interfaces

tools/json_schema_compiler/js_interface_generator_test.py

Index: tools/json_schema_compiler/js_interface_generator_test.py
diff --git a/tools/json_schema_compiler/js_interface_generator_test.py b/tools/json_schema_compiler/js_interface_generator_test.py
new file mode 100755
index 0000000000000000000000000000000000000000..c6813d71a13aaf64fc0f6a60270ce59c8959bf0e
--- /dev/null
+++ b/tools/json_schema_compiler/js_interface_generator_test.py
@@ -0,0 +1,122 @@
+#!/usr/bin/env python
+# Copyright 2015 The Chromium 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 idl_schema
+import json_parse
+from js_interface_generator import JsInterfaceGenerator
+from datetime import datetime
+import model
+import sys
+import unittest
+
+# The contents of a fake idl file.
+fake_idl = """
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// A totally fake API.
+namespace fakeApi {
+  enum Greek {
+    ALPHA,
+    BETA,
+    GAMMA,
+    DELTA
+  };
+
+  dictionary Bar {
+    long num;
+  };
+
+  dictionary Baz {
+    DOMString str;
+    long num;
+    boolean b;
+    Greek letter;
+    Greek? optionalLetter;
+    long[] arr;
+    Bar[]? optionalObjArr;
+    Greek[] enumArr;
+    any[] anythingGoes;
+    Bar obj;
+    long? maybe;
+    (DOMString or Greek or long[]) choice;
+    object plainObj;
+  };
+
+  callback VoidCallback = void();
+
+  callback BazGreekCallback = void(Baz baz, Greek greek);
+
+  interface Functions {
+    // Does something exciting! And what's more, this is a multiline function
+    // comment! It goes onto multiple lines!
+    // |baz| : The baz to use.
+    static void doSomething(Baz baz, VoidCallback callback);
+
+    // |callback| : The callback which will most assuredly in all cases be
+    // called; that is, of course, iff such a callback was provided and is
+    // not at all null.
+    static void bazGreek(optional BazGreekCallback callback);
+
+    [deprecated="Use a new method."] static DOMString returnString();
+  };
+
+  interface Events {
+    // Fired when we realize it's a trap!
+    static void onTrapDetected(Baz baz);
+  };
+};
+"""
+
+# The output we expect from our fake idl file.
+expected_output = JsInterfaceGenerator.GetHeader(sys.argv[0], 'fakeApi') + """
+
+/** @interface */
+function FakeApi() {}
+
+FakeApi.prototype = {
+  /**
+   * Does something exciting! And what's more, this is a multiline function

[Devlin, 2015/12/02 17:58:28]

Will these closure docs conflict with the externs?

[stevenjb, 2015/12/02 18:07:40]

Any @param/@return needs to match, that's pretty much the point. I don't think
the rest matters?

+   * comment! It goes onto multiple lines!
+   * @param {!chrome.fakeApi.Baz} baz The baz to use.
+   * @param {function():void} callback
+   */
+  doSomething: assertNotReached,
+
+  /**
+   * @param {function(!chrome.fakeApi.Baz, !chrome.fakeApi.Greek):void=} callback
+   *     The callback which will most assuredly in all cases be called; that is,
+   *     of course, iff such a callback was provided and is not at all null.
+   */
+  bazGreek: assertNotReached,
+
+  /**
+   * Fired when we realize it's a trap!
+   * @type {!ChromeEvent}
+   */
+  onTrapDetected: new ChromeEvent(),
+
+};"""
+
+class JsExternGeneratorTest(unittest.TestCase):
+  def _GetNamespace(self, fake_content, filename):
+    """Returns a namespace object for the given content"""
+    api_def = idl_schema.Process(fake_content, filename)
+    m = model.Model()
+    return m.AddNamespace(api_def[0], filename)
+
+  def setUp(self):
+    self.maxDiff = None # Lets us see the full diff when inequal.
+
+  def testBasic(self):
+    namespace = self._GetNamespace(fake_idl, 'fake_api.idl')
+    self.assertMultiLineEqual(
+        expected_output,
+        JsInterfaceGenerator().Generate(namespace).Render())
+
+
+if __name__ == '__main__':
+  unittest.main()