Hygiene: Move build/ext.popups/ to src/

This way, src contains sources, and dist contains distribution files.

Also, add some documentation about the folders in the README and an adr.

Change-Id: Ie0b9f6475b8423b90e927633d883bde3cd5d5e4d

.gitattributes

@@ -1,2 +1 @@
-resources/ext.popups/index.js -diff -whitespace
-resources/ext.popups/index.js.map -diff -whitespace
+resources/dist/** -diff -whitespace

Gruntfile.js

@@ -23,7 +23,7 @@ module.exports = function ( grunt ) {
 				]
 			},
 			all: [
-				'build/**',
+				'src/**',
 				'resources/ext.popups/*.js',
 				'resources/ext.popups/**/*.js',
 				'!resources/dist/index.js',

README.md

@@ -6,7 +6,13 @@ what it does.
 ## Development
 
 Popups uses an asset bundler so when developing for the extension you'll need
-to run a script to assemble the frontend assets. So, after an `npm install`:
+to run a script to assemble the frontend assets.
+
+You can find the frontend source files in `src/`, the compiled sources in
+`resources/dist/`, and other frontend assets managed by resource loader in
+`resources/*`.
+
+After an `npm install`:
 
 * `npm start` Will run the bundler in watch mode, re-assembling the files on
   file change.

doc/adr/0005-frontend-sources-directory-structure.md

@@ -0,0 +1,43 @@
+# 1. Frontend sources directory structure
+
+Date: 14/02/2017
+
+## Status
+
+Accepted
+
+## Context
+
+With the addition of a frontend bundler, there are now assets that are the
+source, and assets that are for distribution.
+
+Before, all assets were distribution ones stored in `resources/`, just
+a configurable convention used by the Reading Web team for using MediaWiki's
+ResourceLoader.
+
+In order to facilitate the CI checks and understanding where sources are and
+where compiled sources are, we need to chose two distinct paths for storing
+sources and distribution files.
+
+## Decision
+
+After some discussion, because of ease of understanding to the wider
+development community and the good mapping between the name and what they
+contain, we chose to:
+
+* Put unbundled frontend sources in `src/`.
+* Put bundled distribution files in `dist/` under `resources/` in
+  `resources/dist/`.
+* Files directly distributed by ResourceLoader remain under `resources/*` to
+  follow Reading Web Team's conventions around assets used by ResourceLoader.
+
+## Consequences
+
+* Frontend sources will be under `src/`.
+* After `npm start` or `npm run build` the bundled sources will be under
+  `resources/dist`.
+* Jenkins will check in continuous integration that the sources under `src/`
+  are actually compiled when commited under `resources/dist`.
+* If the `src` path where to become inconvenient because we wanted to add other
+  types of sources in it, we'll move the frontend assets to `src/js` or
+  something more specific.

webpack.config.js

@@ -13,7 +13,7 @@ module.exports = {
 		filename: '/[name].js'
 	},
 	entry: {
-		index: './build/ext.popups/index.js'
+		index: './src/index.js'
 	},
 	devtool: 'source-map'
 };