Webpack (#33)

See https://github.com/flarum/core/pull/1367

* Replace gulp with webpack and npm scripts for JS compilation
* Set up Travis CI to commit compiled JS
* Restructure `js` directory; only one instance of npm, forum/admin are "submodules"
* Restructure `less` directory

extensions/mentions/js/src/forum/utils/reply.js

@@ -0,0 +1,34 @@
+import DiscussionControls from 'flarum/utils/DiscussionControls';
+
+function insertMention(post, component, quote) {
+  const user = post.user();
+  const mention = '@' + (user ? user.username() : post.number()) + '#' + post.id() + ' ';
+
+  // If the composer is empty, then assume we're starting a new reply.
+  // In which case we don't want the user to have to confirm if they
+  // close the composer straight away.
+  if (!component.content()) {
+    component.props.originalContent = mention;
+  }
+
+  const cursorPosition = component.editor.getSelectionRange()[0];
+  const preceding = component.editor.value().slice(0, cursorPosition);
+  const precedingNewlines = preceding.length == 0 ? 0 : 3 - preceding.match(/(\n{0,2})$/)[0].length;
+
+  component.editor.insertAtCursor(
+    Array(precedingNewlines).join('\n') + // Insert up to two newlines, depending on preceding whitespace
+    (quote
+      ? '> ' + mention + quote.trim().replace(/\n/g, '\n> ') + '\n\n'
+      : mention)
+  );
+}
+
+export default function reply(post, quote) {
+  const component = app.composer.component;
+  if (component && component.props.post && component.props.post.discussion() === post.discussion()) {
+    insertMention(post, component, quote);
+  } else {
+    DiscussionControls.replyAction.call(post.discussion())
+      .then(newComponent => insertMention(post, newComponent, quote));
+  }
+}