UX: Prioritize categories autocomplete with new rules.

app/assets/javascripts/discourse/components/d-editor.js.es6

@@ -258,21 +258,7 @@ export default Ember.Component.extend({
         return category.get('slug');
       },
       dataSource(term) {
-        const limit = 5;
-        const regexp = new RegExp(term, 'i');
-        var count = 0;
-        var data = [];
-
-        Category.listByActivity().some(category => {
-          if (category.get('name').match(regexp)) {
-            count++;
-            data.push(category);
-          }
-
-          return count === limit;
-        });
-
-        return data;
+        return Category.search(term);
       },
       triggerRule(textarea, opts) {
         const result = Discourse.Utilities.caretRowCol(textarea);

app/assets/javascripts/discourse/models/category.js.es6

@@ -285,6 +285,51 @@ Category.reopenClass({
 
   reloadById(id) {
     return Discourse.ajax(`/c/${id}/show.json`);
+  },
+
+  search(term, opts) {
+    var limit = 5;
+
+    if (opts) {
+      if (opts.limit === 0) {
+        return [];
+      } else if (opts.limit) {
+        limit = opts.limit;
+      }
+    }
+
+    const emptyTerm = (term === "");
+    const categories = Category.listByActivity();
+    const length = categories.length;
+    var i;
+    var count = 0;
+    var data = [];
+
+    const done = () => {
+      return data.length === limit;
+    }
+
+    for (i = 0; i < length && !done(); i++) {
+      const category = categories[i];
+      if ((emptyTerm) ||
+          (!emptyTerm && category.get('name').indexOf(term) === 0)) {
+        data.push(category);
+      }
+    }
+
+    if (!done()) {
+      for (i = 0; i < length && !done(); i++) {
+        const category = categories[i];
+
+        if ((!emptyTerm && category.get('name').indexOf(term) > 0)) {
+          if (data.indexOf(category) === -1) data.push(category);
+        }
+      }
+    }
+
+    return _.sortBy(data, (category) => {
+      return category.get('read_restricted');
+    });
   }
 });
 

test/javascripts/models/category-test.js.es6

@@ -1,4 +1,5 @@
 import createStore from 'helpers/create-store';
+import Category from 'discourse/models/category';
 
 module("model:category");
 
@@ -50,6 +51,8 @@ test('findBySlug', function() {
   deepEqual(Discourse.Category.findBySlug('뉴스피드', '熱帶風暴畫眉'), newsFeed, 'we can find a category with CJK slug whose parent slug is also CJK');
   deepEqual(Discourse.Category.findBySlug('时间', 'darth'), time, 'we can find a category with CJK slug whose parent slug is english');
   deepEqual(Discourse.Category.findBySlug('bah', '熱帶風暴畫眉'), bah, 'we can find a category with english slug whose parent slug is CJK');
+
+  sandbox.restore();
 });
 
 test('findSingleBySlug', function() {
@@ -122,3 +125,47 @@ test('postCountStats', function() {
   result = category5.get('postCountStats');
   equal(result.length, 0, "should show nothing");
 });
+
+test('search', () => {
+  const result = (term, opts) => {
+    return Category.search(term, opts).map((category) => category.get('id'));
+  }
+
+  const store = createStore(),
+        category1 = store.createRecord('category', { id: 1, name: 'middle term' }),
+        category2 = store.createRecord('category', { id: 2, name: 'middle term' });
+
+  sandbox.stub(Category, "listByActivity").returns([category1, category2]);
+
+  deepEqual(result('term', { limit: 0 }), [], "returns an empty array when limit is 0");
+  deepEqual(result(''), [category1.get('id'), category2.get('id')], "orders by activity if no term is matched");
+  deepEqual(result('term'), [category1.get('id'), category2.get('id')], "orders by activity");
+
+  category2.set('name', 'term start');
+  deepEqual(result('term'), [category2.get('id'), category1.get('id')], "orders matching begin with and then contains");
+
+  sandbox.restore();
+
+  const category3 = store.createRecord('category', { id: 3, name: 'term start', parent_category_id: category1.get('id') }),
+        category4 = store.createRecord('category', { id: 4, name: 'some term', read_restricted: true });
+
+  sandbox.stub(Category, "listByActivity").returns([category4, category1, category3, category2]);
+
+  deepEqual(result(''),
+            [category1.get('id'), category3.get('id'), category2.get('id'), category4.get('id')],
+            "prioritize non read_restricted categories when term is blank");
+
+  deepEqual(result('', { limit: 3 }),
+            [category1.get('id'), category3.get('id'), category4.get('id')],
+            "prioritize non read_restricted categories when term is blank with limit");
+
+  deepEqual(result('term'),
+            [category3.get('id'), category2.get('id'), category1.get('id'), category4.get('id')],
+            "prioritize non read_restricted");
+
+  deepEqual(result('term', { limit: 3 }),
+            [category3.get('id'), category2.get('id'), category4.get('id')],
+            "prioritize non read_restricted with limit");
+
+  sandbox.restore();
+});