Create a build environment for Chrome Extension

For developers:

```
$ git clone https://github.com/rails/web-console.git
$ cd web-console/extensions
$ bundle install
$ npm run crx
=> Chrome will be launched with the extension.
```

Some gulp tasks are provided:

* gulp crx
  - Build chrome extension.
* gulp crx/zip
  - Generate a .zip file for Chrome Web Store
* gulp crx/pkg
  - Generate a .crx file.

.gitignore

@@ -9,3 +9,5 @@ test/dummy/tmp/
 test/dummy/.sass-cache
 Gemfile.lock
 node_modules/
+dist/
+tmp/

extensions/README.markdown

@@ -0,0 +1,12 @@
+# Web Console Browser Extensions
+
+## Development
+
+### Quickstart
+
+```shell
+$ git clone https://github.com/rails/web-console.git
+$ cd web-console/brx
+$ bundle install
+$ npm run crx
+```

extensions/gulpfile.coffee

@@ -0,0 +1,13 @@
+global.gulp = require("gulp")
+
+path = require("path")
+
+global.templatePath = (target = "")->
+  path.resolve path.join(__dirname, "../lib/web_console/templates", target)
+
+global.distpath = (target = "")->
+  path.resolve path.join(__dirname, "./dist", target)
+
+# load tasks
+glob = require("glob").sync
+glob(path.join __dirname, "gulpfiles/*.coffee").forEach require

extensions/gulpfiles/crx.coffee

@@ -0,0 +1,66 @@
+# Tasks to build chrome extension.
+do (buildTask = "crx")->
+  taskName = (task)-> "#{buildTask}/#{task}"
+  output = (path = "")-> distpath "crx/#{path}"
+
+  # Build a chrome extension. Compiled sources is generated
+  # into a directory called "dist/crx/".
+  gulp.task buildTask, [taskName("src")]
+
+  # Launch a browser with the extension.
+  gulp.task taskName("run"), [buildTask], ->
+    run = require("gulp-run")
+    run("sh scripts/run_chrome.sh --load-extension=\"#{output ""}\"").exec()
+
+  # Generate a .zip file for Chrome Web Store.
+  gulp.task taskName("zip"), [buildTask], ->
+    zip = require("gulp-zip")
+    manifest = require(distpath "crx/manifest.json")
+    filename = "#{manifest.name}-#{manifest.version}.zip"
+    gulp.src [output("**/*"), "!#{output "key.pem"}"]
+      .pipe zip(filename)
+      .pipe gulp.dest(distpath "")
+
+  # Generate a .crx file.
+  gulp.task taskName("pkg"), [buildTask], ->
+    run = require("gulp-run")
+    manifest = require(distpath "crx/manifest.json")
+    filename = "#{manifest.name}-#{manifest.version}.crx"
+    run("\"$(npm bin)/crx\" pack #{output ""} -o #{distpath filename}").exec()
+
+  do (srcTask = "#{buildTask}/src")->
+    taskName = (task)-> "#{srcTask}/#{task}"
+
+    gulp.task srcTask, [
+      "js"
+      "html"
+      "img"
+      "lib/templates"
+      "manifest.json"
+    ].map taskName
+
+    gulp.task taskName("js"), ->
+      gulp.src ["chrome/js/**/*.js"]
+        .pipe gulp.dest(output "js/")
+
+    gulp.task taskName("img"), ->
+      gulp.src ["img/**/*.png"]
+        .pipe gulp.dest(output "img/")
+
+    gulp.task taskName("manifest.json"), ->
+      gulp.src ["chrome/manifest.json"]
+        .pipe gulp.dest(output "")
+
+    gulp.task taskName("lib/templates"), ["tmp/templates"], ->
+      gulp.src ["tmp/templates/**/*.js"]
+        .pipe gulp.dest(output "lib/")
+
+    gulp.task taskName("html"), ->
+      gulp.src ["chrome/html/**/*.html"]
+        .pipe gulp.dest(output "html/")
+
+    gulp.task taskName("watch"), ->
+      gulp.watch [templatePath "**/*.erb"], [taskName "lib"]
+      gulp.watch ["chrome/js/**/*.js"], [taskName "js"]
+      gulp.watch ["chrome/manifest.json"], [taskName "manifest.json"]
+      gulp.watch ["chrome/html/**/*.html"], [taskName "html"]

extensions/gulpfiles/lib/erb_helper.rb

@@ -0,0 +1,19 @@
+require "web_console/fake_middleware"
+
+def root(path = "")
+  Pathname(File.expand_path "../../../../", __FILE__).join(path).to_s
+end
+
+def fake_view
+  @_view ||= WebConsole::FakeMiddleware.new(
+    view_path: root("lib/web_console/templates"),
+  ).view
+end
+
+def method_missing(name, *args, &block)
+  if name.to_s.start_with?("render") && fake_view.respond_to?(name)
+    fake_view.send name, *args, &block
+  else
+    super
+  end
+end

extensions/gulpfiles/templates.coffee

@@ -0,0 +1,16 @@
+do (output = "tmp/templates")->
+  taskName = (task)->
+    "#{output}/#{task}"
+
+  gulp.task output, [
+    "erb"
+  ].map taskName
+
+  # Pre-compile *.js.erb.
+  gulp.task taskName("erb"), ->
+    run = require("gulp-run")
+    rename = require("gulp-rename")
+    gulp.src [templatePath "**/*.js.erb"]
+      .pipe run("bundle exec erb -r ./gulpfiles/lib/erb_helper", verbosity: 0)
+      .pipe rename(extname: "")
+      .pipe gulp.dest(output)

extensions/package.json

@@ -0,0 +1,17 @@
+{
+  "name": "brx-web-console",
+  "version": "0.0.0",
+  "devDependencies": {
+    "coffee-script": "^1.9.3",
+    "crx": "^3.0.2",
+    "glob": "^5.0.13",
+    "gulp": "^3.9.0",
+    "gulp-rename": "^1.2.2",
+    "gulp-run": "^1.6.8",
+    "gulp-zip": "^3.0.2"
+  },
+  "scripts": {
+    "crx": "npm install && node \"$(npm bin)/gulp\" crx/run"
+  },
+  "license": "MIT"
+}

extensions/scripts/run_chrome.sh

@@ -0,0 +1,25 @@
+#!/bin/sh
+
+is_command() {
+  type "$1" > /dev/null 2>&1
+}
+
+find_chrome_binary() {
+  for name in "chromium" "google-chrome" "chromium-browser"; do
+    if is_command "$name"; then
+      echo $name
+      return
+    fi
+  done
+}
+
+CHROME_BINARY=${CHROME_BINARY:-`find_chrome_binary`}
+
+if is_command $CHROME_BINARY; then
+  echo $CHROME_BINARY "$@"
+  $($CHROME_BINARY "$@")
+else
+  echo "Chrome is not found ($CHROME_BINARY)."
+  echo "Try 'CHROME_BINARY=path/to/chrome'."
+  exit 1
+fi