Registered key commands can override built-in functionality

src/js/editor/editor.js

@@ -584,6 +584,10 @@ class Editor {
       this._insertEmptyMarkupSectionAtCursor();
     }
 
+    if (this.handleKeyCommand(event)) {
+      return;
+    }
+
     const key = Key.fromEvent(event);
 
     if (key.isDelete()) {
@@ -600,7 +604,6 @@ class Editor {
     }
 
     this.handleExpansion(event);
-    this.handleKeyCommand(event);
   }
 
   /**
@@ -614,6 +617,7 @@ class Editor {
    *
    * @method handleKeyCommand
    * @param {Event} event The keyboard event triggered by the user
+   * @return {Boolean} true when a command was successfully run
    * @private
    */
   handleKeyCommand(event) {
@@ -622,9 +626,10 @@ class Editor {
       let keyCommand = keyCommands[i];
       if (keyCommand.run(this) !== false) {
         event.preventDefault();
-        return;
+        return true;
       }
     }
+    return false;
   }
 
   handlePaste(event) {

tests/acceptance/editor-key-commands-test.js

@@ -150,3 +150,56 @@ test('returning false from key command causes next match to run', (assert) => {
   assert.ok(!!firstCommandRan, 'first registered method is called');
 });
 
+test('key commands can override built-in functionality', (assert) => {
+  const mobiledoc = Helpers.mobiledoc.build(
+    ({post, markupSection, marker}) => post([
+      markupSection('p', [marker('something')])
+    ]));
+
+  editor = new Editor({mobiledoc});
+
+  let passedEditor;
+  editor.registerKeyCommand({
+    str: 'enter',
+    run(editor) { passedEditor = editor; }
+  });
+
+  editor.render(editorElement);
+  assert.equal($('#editor p').length, 1, 'has 1 paragraph to start');
+
+  Helpers.dom.moveCursorTo(editorElement.childNodes[0].childNodes[0], 5);
+  Helpers.dom.triggerEnter(editor);
+
+  assert.ok(!!passedEditor && passedEditor === editor, 'run method is called');
+
+  assert.equal($('#editor p').length, 1, 'still has just one paragraph');
+});
+
+test('returning false from key command still runs built-in functionality', (assert) => {
+  const mobiledoc = Helpers.mobiledoc.build(
+    ({post, markupSection, marker}) => post([
+      markupSection('p', [marker('something')])
+    ]));
+
+  editor = new Editor({mobiledoc});
+
+  let passedEditor;
+  editor.registerKeyCommand({
+    str: 'enter',
+    run(editor) {
+      passedEditor = editor;
+      return false;
+    }
+  });
+
+  editor.render(editorElement);
+  assert.equal($('#editor p').length, 1, 'has 1 paragraph to start');
+
+  Helpers.dom.moveCursorTo(editorElement.childNodes[0].childNodes[0], 5);
+  Helpers.dom.triggerEnter(editor);
+
+  assert.ok(!!passedEditor && passedEditor === editor, 'run method is called');
+
+  assert.equal($('#editor p').length, 2, 'has added a new paragraph');
+});
+