Implement skeleton codes for a new version of WebIDL compiler (#208)

This is a new initial implementation of WebIDL compiler. It has the
following differences compared to the existing one.
  - It is built by `gulp` instead of `gyp`
  - No longer build `generator` and `webidl` separately

ISSUE=#207

.appveyor.yml

@@ -7,6 +7,7 @@ branches:
     - master
 
 build_script:
+  - bacardi clean && bacardi build_webidl
   - bacardi clean && bacardi build
 
 test_script:

.travis.yml

@@ -27,5 +27,6 @@ before_install:
   - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then sudo apt-get install g++ git make python wget; fi
 
 script:
+  - ./bacardi clean && ./bacardi build_webidl
   - ./bacardi clean && ./bacardi build && ./bacardi lint && ./bacardi test
   - ./bacardi clean && ./bacardi build_electron

bootstrap/bacardi.sh

@@ -49,4 +49,5 @@ for command in $(ls $(bootstrap_command_path)); do
   fi
 done
 
+export NODE_PATH=$(bacardi_path)
 gulp $@

docs/webidl_compiler.md

@@ -0,0 +1,37 @@
+# WebIDL compiler
+This document explains how `./bacardi build_webidl` works internally.
+
+- [Triggering WebIDL compiler](#triggering-webidl-compiler)
+
+## Triggering WebIDL compiler
+
+![Triggering WebIDL compiler process](/docs/images/triggering_webidl_compiler.png)
+To request building WebIDL, you can just use `./bacardi build_webidl` command.
+
+1. `bacardi build_webidl` command will run `gulp build_webidl` internally.
+2. In our project, the `gulp` command will run on `ts-node` runtime.
+So, `ts-node` will request to build all related TypeScript modules internally.
+3. Then, `ts-node` will generate JS codes using TypeScript compiler.
+4. In this step, queries all `*.idl` files in this project.
+5. Pass the found WebIDL file list and request to compile WebIDL files.
+
+### bootstrap
+The bootstrap is set of scripts that provide required packages via auto-install
+in multi-platform environment. With this module, we can handle everything to
+build and run our project without any additional works.
+
+### gulp
+The [gulp](https://github.com/gulpjs/gulp) provides the streaming build system.
+In our project, `./bacardi <command>` will trigger `gulp <task>` internally.
+
+### ts-node
+The [ts-node](https://github.com/TypeStrong/ts-node) is a runtime for TypeScript
+for Node.js. It makes our TypeScript codes run on Node.js without explicit
+TypeScript compile. So, this makes `gulpfile.ts` work. Also, When processing
+gulp tasks such as the `build_webidl` as shown in the figure above, the WebIDL
+compiler codes(TypeScript codes) is executed by performing TypeScript compiling
+internally.
+
+### WebIDL compiler
+The WebIDL compiler(or often we called bindings generator) transcompiles WebIDL
+to Native codes such as C++ codes.

generator/index.ts

@@ -0,0 +1,27 @@
+/**
+ * Copyright (c) 2017 The Bacardi Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as assert from 'assert';
+
+export async function run(idlFiles: string[]): Promise<number> {
+  assert(idlFiles.indexOf('test/test_interface.idl') >= 0);
+  assert(idlFiles.indexOf('examples/calculator.idl') >= 0);
+  assert(idlFiles.indexOf('examples/electron/native/electron_native.idl') >= 0);
+
+  // Not implemented yet.
+
+  return 0;
+}

gulpfile.ts

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+import * as generator from 'generator';
+import * as globs from 'globs';
 import * as gulp from 'gulp';
 import * as shell from 'gulp-shell';
 import gulpTslint from 'gulp-tslint';
@@ -29,6 +31,15 @@ gulp.task('default', () => {
   return;
 });
 
+/**
+ * Build WebIDL
+ */
+gulp.task('build_webidl', (callback) => {
+  globs(['examples/**/*.idl', 'test/**/*.idl'], async(error, files) => {
+    callback(await generator.run(files));
+  });
+});
+
 /**
  * This task will be used in binding.gyp to build native files.
  */
@@ -100,7 +111,10 @@ gulp.task('lint_native', shell.task([
 gulp.task('lint_ts', () => {
   const program: ts.Program = tslint.Linter.createProgram('tsconfig.json');
 
-  return gulp.src('gulpfile.ts')
+  return gulp.src([
+        'gulpfile.ts',
+        'generator/index.ts'
+      ])
       .pipe(gulpTslint({
           formatter: 'codeFrame',
           program: program
@@ -113,7 +127,10 @@ gulp.task('lint_ts', () => {
 gulp.task('lint_ts:fix', () => {
   const program: ts.Program = tslint.Linter.createProgram('tsconfig.json');
 
-  return gulp.src('gulpfile.ts')
+  return gulp.src([
+        'gulpfile.ts',
+        'generator/index.ts'
+      ])
       .pipe(gulpTslint({
           formatter: 'codeFrame',
           program: program,

package.json

@@ -8,6 +8,7 @@
     "change-case": "^3.0.1",
     "electron": "^1.7.8",
     "electron-rebuild": "^1.6.0",
+    "globs": "^0.1.3",
     "gulp": "^3.9.1",
     "gulp-shell": "^0.6.3",
     "gulp-tslint": "^8.1.2",