[BUGFIX] Ensure Editor#hasActiveMarkup detects complex markups

When checking for a markup with attributes (e.g., an A markup with
'href' attribute), `hasActiveMarkup` used to coerce the 'a' string
argument to a markup and then fail to consider an existing (different)
"A" markup (with different attributes) as a match for 'a'.

src/js/editor/editor.js

@@ -487,8 +487,15 @@ class Editor {
    * @return {boolean}
    */
   hasActiveMarkup(markup) {
-    markup = this.builder._coerceMarkup(markup);
-    return contains(this.activeMarkups, markup);
+    let matchesFn;
+    if (typeof markup === 'string') {
+      markup = markup.toLowerCase();
+      matchesFn = (_markup) => _markup.tagName === markup;
+    } else {
+      matchesFn = (_markup) => _markup === markup;
+    }
+
+    return !!detect(this.activeMarkups, matchesFn);
   }
 
   get markupsInSelection() {

src/js/models/post-node-builder.js

@@ -162,16 +162,6 @@ class PostNodeBuilder {
 
     return markup;
   }
-
-  /**
-   * @param {Markup|String} markupOrString
-   * @return {Markup}
-   * @private
-   */
-  _coerceMarkup(markupOrString, attributes={}) {
-    let tagName = typeof markupOrString === 'string' ? markupOrString : markupOrString.tagName;
-    return this.createMarkup(tagName, attributes);
-  }
 }
 
 export default PostNodeBuilder;

tests/unit/editor/editor-test.js

@@ -338,3 +338,28 @@ test('#activeMarkups returns the markups at cursor when range is collapsed', (as
   editor.selectRange(Range.create(head, 'abcdefg'.length));
   assert.equal(editor.activeMarkups.length, 0, 'no active markups after end of bold text');
 });
+
+test('#hasActiveMarkup returns true for complex markups', (assert) => {
+  editor = Helpers.mobiledoc.renderInto(editorElement, ({post, markupSection, marker, markup}) => {
+    return post([markupSection('p', [
+      marker('abc'),
+      marker('def', [markup('a', {href: 'http://bustle.com'})]),
+      marker('ghi')
+    ])]);
+  });
+
+  let head = editor.post.sections.head;
+  editor.selectRange(Range.create(head, 'abc'.length));
+  assert.equal(editor.activeMarkups.length, 0, 'no active markups at left of bold text');
+
+  editor.selectRange(Range.create(head, 'abcd'.length));
+  assert.equal(editor.activeMarkups.length, 1, 'active markups in linked text');
+  assert.ok(editor.hasActiveMarkup('a'), 'has A active markup');
+
+  editor.selectRange(Range.create(head, 'abcdef'.length));
+  assert.equal(editor.activeMarkups.length, 1, 'active markups at end of linked text');
+  assert.ok(editor.hasActiveMarkup('a'), 'has A active markup');
+
+  editor.selectRange(Range.create(head, 'abcdefg'.length));
+  assert.equal(editor.activeMarkups.length, 0, 'no active markups after end of linked text');
+});