mojo-ts: Add necessary things for minimum TS/JS bindings generation

Adds:

1. "enable_typescript_bindings" gn arg, which must be set to true
   to test Typescript bindings.
2. "use_typescript_sources" gn variable that can be set to opt-in a
   target into generating Typescript bindings.
3. Test interfaces folder where interfaces will be added as features
   are implemented.
4. A mojom gn target that includes the tests interfaces. This target is
   included as part of mojo_unittests
5. Basic template and generator implementation.
6. Script to compile generated Typescript bindings into JS bindings.

Bug: 1002798
Change-Id: Id8424d707ad4b2ec9a773b291fd4a41332623274
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1817860Reviewed-by: Dan Beam <dbeam@chromium.org>
Reviewed-by: Ken Rockot <rockot@google.com>
Commit-Queue: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#699993}

mojo/BUILD.gn

@@ -41,6 +41,7 @@ test("mojo_unittests") {
     "//mojo/public/cpp/bindings/tests",
     "//mojo/public/cpp/platform/tests",
     "//mojo/public/cpp/system/tests",
+    "//mojo/public/js/ts/bindings/tests",
   ]
 }
 

mojo/public/js/ts/README.md

+# Mojo Typescript/JavaScript Bindings
+
+Generated Mojo Typescript bindings are compiled to plain JavaScript bindings for
+plain JavaScript clients and to Closure-annotated JavaScript for Closure
+clients.
+
+**These bindings are work in progress and are not ready for general use.**
+
+## Getting started
+
+To use the Typescript bindings to generate JS bindings, set
+`use_typescript_sources` to true in your mojom target:
+
+```
+mojom("interfaces") {
+  sources = [
+    "echo.mojom",
+  ]
+  use_typescript_sources = true
+}
+```
+
+and add `enable_typescript_bindings = true` to your `args.gn`.
+
+## Tests
+There are two sets of tests: compilation and runtime.
+
+* Compilation tests are done by including the
+`//mojo/public/js/ts/bindings/tests` gn target, which triggers the Typescript
+bindings generation and their compilation. This target is included as part of
+`mojo_unittests`.
+
+* Runtime tests are done as part of Blink's Web Tests. They are in
+`//third_party/blink/web_tests/mojo/bindings-lite-*.html`.

mojo/public/js/ts/bindings/tests/BUILD.gn

+# Copyright 2019 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("//mojo/public/tools/bindings/mojom.gni")
+
+# Partial copy of //mojo/public/interfaces/bindings/tests:test_interfaces. Used
+# to incrementally develop Typescript bindings.
+mojom("test_interfaces") {
+  testonly = true
+  sources = [
+    "module.test-mojom",
+  ]
+  use_typescript_sources = true
+}
+
+source_set("tests") {
+  testonly = true
+  deps = [
+    ":test_interfaces_js",
+  ]
+}

mojo/public/js/ts/bindings/tests/module.test-mojom

+// Copyright 2019 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.
+
+// Empty Mojo module. Used to incrementally develop Typescript Bindings.
+module mojo.tstest;

mojo/public/tools/bindings/BUILD.gn

@@ -79,6 +79,8 @@ action("precompile_templates") {
     "$mojom_generator_root/generators/js_templates/struct_definition.tmpl",
     "$mojom_generator_root/generators/js_templates/union_definition.tmpl",
     "$mojom_generator_root/generators/js_templates/validation_macros.tmpl",
+    "$mojom_generator_root/generators/ts_templates/module_definition.tmpl",
+    "$mojom_generator_root/generators/ts_templates/mojom.tmpl",
   ]
   script = mojom_generator_script
 
@@ -87,6 +89,7 @@ action("precompile_templates") {
     "$target_gen_dir/cpp_templates.zip",
     "$target_gen_dir/java_templates.zip",
     "$target_gen_dir/js_templates.zip",
+    "$target_gen_dir/ts_templates.zip",
   ]
   args = [
     "--use_bundled_pylibs",

mojo/public/tools/bindings/compile_typescript.py

+# Copyright 2019 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 os
+import sys
+import argparse
+
+_HERE_PATH = os.path.dirname(__file__)
+_SRC_PATH = os.path.normpath(os.path.join(_HERE_PATH, '..', '..', '..', '..'))
+
+sys.path.append(os.path.join(_SRC_PATH, 'third_party', 'node'))
+import node
+import node_modules
+
+def main(argv):
+  parser = argparse.ArgumentParser()
+  parser.add_argument('--filelist', required=True)
+  args = parser.parse_args(argv)
+
+  files = []
+  with open(args.filelist) as filelist_file:
+    for line in filelist_file:
+      for f in line.split():
+        files.append(os.path.join(os.getcwd(), f))
+
+  file_paths = ' '.join(files)
+
+  result = node.RunNode(
+      [node_modules.PathToTypescript()] +
+      [
+          "--target 'es6'",
+          "--module 'es6'",
+          "--lib 'es6'",
+          "--strict",
+          file_paths
+      ])
+  if len(result) != 0:
+    raise RuntimeError('Failed to compile Typescript: \n%s' % result)
+
+if __name__ == '__main__':
+  main(sys.argv[1:])

mojo/public/tools/bindings/generators/mojom_ts_generator.py

+# Copyright 2019 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.
+
+"""Generates Typescript source files from a mojom.Module."""
+
+import mojom.generate.generator as generator
+from mojom.generate.template_expander import UseJinja
+
+class TypescriptStylizer(generator.Stylizer):
+  def StylizeModule(self, mojom_namespace):
+    return '.'.join(generator.ToCamel(word, lower_initial=True)
+                        for word in mojom_namespace.split('.'))
+
+class Generator(generator.Generator):
+  def _GetParameters(self, use_es_modules=False):
+    return {
+      "module": self.module,
+      "use_es_modules": use_es_modules,
+   }
+
+  @staticmethod
+  def GetTemplatePrefix():
+    return "ts_templates"
+
+  def GetFilters(self):
+    ts_filters = {}
+    return ts_filters
+
+  @UseJinja("mojom.tmpl")
+  def _GenerateBindings(self):
+    return self._GetParameters()
+
+  @UseJinja("mojom.tmpl")
+  def _GenerateESModulesBindings(self):
+    return self._GetParameters(use_es_modules=True)
+
+  def GenerateFiles(self, args):
+    if self.variant:
+      raise Exception("Variants not supported in JavaScript bindings.")
+
+    self.module.Stylize(TypescriptStylizer())
+
+    self.Write(self._GenerateBindings(), "%s-lite.ts" % self.module.path)
+    self.Write(self._GenerateESModulesBindings(),
+               "%s-lite.m.ts" % self.module.path)

mojo/public/tools/bindings/generators/ts_templates/module_definition.tmpl

+{%- if not use_es_modules %}
+namespace {{module.namespace}} {
+{% endif %}
+{%- if not use_es_modules %}
+} // namespace {{module.namespace}}
+{% endif %}

mojo/public/tools/bindings/generators/ts_templates/mojom.tmpl

+// Copyright 2019 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.
+
+{% include "module_definition.tmpl" %}

mojo/public/tools/bindings/mojom.gni

@@ -43,6 +43,9 @@ declare_args() {
   # Enable adding annotations to generated C++ headers that are used for
   # cross-references in CodeSearch.
   enable_kythe_annotations = false
+
+  # Enables generating Typescript bindings and compiling them to JS bindings.
+  enable_typescript_bindings = false
 }
 
 # NOTE: We would like to avoid scrambling message IDs where it doesn't add
@@ -64,6 +67,7 @@ enable_scrambled_message_ids =
      ((enable_nacl || is_nacl || is_nacl_nonsfi) && target_os != "chromeos"))
 
 mojom_generator_root = "//mojo/public/tools/bindings"
+compile_typescript_script = "$mojom_generator_root/compile_typescript.py"
 mojom_generator_script = "$mojom_generator_root/mojom_bindings_generator.py"
 mojom_generator_sources = [
   "$mojom_generator_root/generators/mojom_cpp_generator.py",
@@ -286,6 +290,9 @@ if (enable_mojom_typemapping) {
 #       Use old names i.e. FooProxy, Foo, getProxy(), etc. instead of the new
 #       names i.e. FooRemote, FooReceiver, getRemote(), etc.
 #
+#   use_typescript_sources (optional)
+#       Uses the Typescript generator to generate JavaScript bindings.
+#
 # The following parameters are used to support the component build. They are
 # needed so that bindings which are linked with a component can use the same
 # export settings for classes. The first three are for the chromium variant, and
@@ -1221,7 +1228,16 @@ template("mojom") {
     }
   }
 
-  if (generate_fuzzing || !defined(invoker.cpp_only) || !invoker.cpp_only) {
+  use_typescript_for_target =
+      enable_typescript_bindings && defined(invoker.use_typescript_sources) &&
+      invoker.use_typescript_sources
+
+  if (!use_typescript_for_target && defined(invoker.use_typescript_sources)) {
+    not_needed(invoker, [ "use_typescript_sources" ])
+  }
+
+  if ((generate_fuzzing || !defined(invoker.cpp_only) || !invoker.cpp_only) &&
+      !use_typescript_for_target) {
     if (defined(invoker.sources)) {
       generator_js_target_name = "${target_name}_js__generator"
       generator_js_lite_outputs =
@@ -1355,6 +1371,79 @@ template("mojom") {
       }
     }
   }
+  if ((generate_fuzzing || !defined(invoker.cpp_only) || !invoker.cpp_only) &&
+      use_typescript_for_target) {
+    generator_ts_target_name = "${target_name}_ts__generator"
+
+    source_filelist = []
+    ts_filelist = []
+    ts_outputs = []
+    js_outputs = []
+    foreach(source, invoker.sources) {
+      source_filelist += [ rebase_path("$source", root_build_dir) ]
+      ts_outputs += [
+        "$target_gen_dir/$source-lite.ts",
+        "$target_gen_dir/$source-lite.m.ts",
+      ]
+      ts_filelist += [
+        rebase_path("$target_gen_dir/$source-lite.ts", root_build_dir),
+        rebase_path("$target_gen_dir/$source-lite.m.ts", root_build_dir),
+      ]
+
+      js_outputs += [
+        "$target_gen_dir/$source-lite.js",
+        "$target_gen_dir/$source-lite.m.js",
+      ]
+    }
+
+    generator_ts_target_name = "${target_name}_ts__generator"
+    action(generator_ts_target_name) {
+      script = mojom_generator_script
+      inputs = mojom_generator_sources + jinja2_sources
+      sources = invoker.sources
+      deps = [
+               ":$parsed_target_name",
+               "//mojo/public/tools/bindings:precompile_templates",
+             ] + verify_deps_target_names
+      outputs = ts_outputs
+      args = common_generator_args
+      response_file_contents = source_filelist
+
+      args += [
+        "--filelist={{response_file_name}}",
+        "-g",
+        "typescript",
+      ]
+
+      # TODO(crbug.com/1007587): Support scramble_message_ids.
+      # TODO(crbug.com/1007591): Support generate_fuzzing.
+    }
+
+    generator_js_target_name = "${target_name}_js__generator"
+    action(generator_js_target_name) {
+      script = compile_typescript_script
+      sources = ts_outputs
+      outputs = js_outputs
+      public_deps = [
+        ":$generator_ts_target_name",
+      ]
+      response_file_contents = ts_filelist
+      args = [ "--filelist={{response_file_name}}" ]
+    }
+
+    js_target_name = target_name + "_js"
+    group(js_target_name) {
+      public_deps = []
+      if (defined(invoker.sources)) {
+        public_deps += [ ":$generator_js_target_name" ]
+      }
+
+      foreach(d, all_deps) {
+        full_name = get_label_info(d, "label_no_toolchain")
+        public_deps += [ "${full_name}_js" ]
+      }
+    }
+  }
 }
 
 # A helper for the mojom() template above when component libraries are desired

mojo/public/tools/bindings/mojom_bindings_generator.py

@@ -61,6 +61,7 @@ _BUILTIN_GENERATORS = {
   "c++": "mojom_cpp_generator",
   "javascript": "mojom_js_generator",
   "java": "mojom_java_generator",
+  "typescript": "mojom_ts_generator",
 }
 
 

third_party/node/node_modules.py

@@ -36,3 +36,8 @@ def PathToSvgo():
 
 def PathToUglify():
   return _path_in_node_modules('uglify-es', 'bin', 'uglifyjs')
+
+# Typescript is not approved for general use in Chromium. Email chromium-dev
+# if you want to use it.
+def PathToTypescript():
+  return _path_in_node_modules('typescript', 'bin', 'tsc')