[BUGFIX] Do not handle key events when the editor has no cursor

It is possible for the editor's element to be focused but not have a
cursor (selection). In this case, key events will fire on the editor's
element but the editor will not be able to determine a logical
`Position` (since there is no selection). When this happens, we abort
handling the key event.

fixes #344

Author: bantic

src/js/editor/editor.js

@@ -258,7 +258,7 @@ class Editor {
   }
 
   handleNewline(event) {
-    if (!this.cursor.hasCursor()) { return; }
+    if (!this.hasCursor()) { return; }
 
     event.preventDefault();
 
@@ -503,9 +503,20 @@ class Editor {
     this._views = [];
   }
 
+  /**
+   * Whether the editor has a cursor (or a selected range).
+   * It is possible for the editor to be focused but not have a selection.
+   * In this case, key events will fire but the editor will not be able to
+   * determine a cursor position.
+   * @return {bool}
+   */
+  hasCursor() {
+    return this.cursor.hasCursor();
+  }
+
   destroy() {
     this._isDestroyed = true;
-    if (this.cursor.hasCursor()) {
+    if (this.hasCursor()) {
       this.cursor.clearSelection();
       this.element.blur(); // FIXME This doesn't blur the element on IE11
     }

src/js/editor/event-manager.js

@@ -83,14 +83,16 @@ export default class EventManager {
   }
 
   keypress(event) {
+    let { editor } = this;
+    if (!editor.hasCursor()) { return; }
+
     let key = Key.fromEvent(event);
     if (!key.isPrintable()) {
       return;
+    } else {
+      event.preventDefault();
     }
 
-    event.preventDefault();
-
-    let { editor } = this;
     if (editor.handleExpansion(event)) {
       return;
     } else {
@@ -100,17 +102,15 @@ export default class EventManager {
 
   keydown(event) {
     let { editor } = this;
-    if (!editor.isEditable) {
-      return;
-    }
+    if (!editor.hasCursor()) { return; }
+    if (!editor.isEditable) { return; }
+
     let key = Key.fromEvent(event);
     if (key.isShiftKey()) {
       this.isShift = true;
     }
 
-    if (editor.handleKeyCommand(event)) {
-      return;
-    }
+    if (editor.handleKeyCommand(event)) { return; }
 
     if (editor.post.isBlank) {
       editor._insertEmptyMarkupSectionAtCursor();
@@ -145,6 +145,8 @@ export default class EventManager {
   }
 
   keyup(event) {
+    let { editor } = this;
+    if (!editor.hasCursor()) { return; }
     let key = Key.fromEvent(event);
     if (key.isShiftKey()) {
       this.isShift = false;

tests/acceptance/basic-editor-test.js

@@ -265,3 +265,22 @@ test('adding/removing bold text between two bold markers works', (assert) => {
   assert.hasElement('#editor b:contains(def)', 'removes B from middle, leaves def');
   assert.hasNoElement('#editor b:contains(123)', 'removes B from middle');
 });
+
+test('keypress events when the editor does not have selection are ignored', (assert) => {
+  let expected;
+  editor = Helpers.mobiledoc.renderInto(editorElement, ({post, markupSection, marker}) => {
+    expected = post([markupSection('p', [marker('abc')])]);
+    return post([
+      markupSection('p', [marker('abc')])
+    ]);
+  });
+
+  Helpers.dom.clearSelection();
+
+  assert.ok(document.activeElement === editorElement, 'precond - editor is focused');
+  assert.equal(window.getSelection().rangeCount, 0, 'nothing selected');
+
+  Helpers.dom.insertText(editor, 'v');
+
+  assert.postIsSimilar(editor.post, expected, 'post is not changed');
+});

tests/helpers/dom.js

@@ -247,6 +247,11 @@ function triggerKeyCommand(editor, string, modifiers=[]) {
   _triggerEditorEvent(editor, keyEvent);
 }
 
+function triggerKeyEvent(editor, type, options) {
+  let event = createMockEvent(type, editor.element, options);
+  _triggerEditorEvent(editor, event);
+}
+
 function triggerRightArrowKey(editor, modifier) {
   if (!(editor instanceof Editor)) {
     throw new Error('Must pass editor to triggerRightArrowKey');