✨ Import text-editor code into the repository

frontend/text-editor/editor/commands/deleteContentBackward.js

@@ -0,0 +1,53 @@
+/**
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * Copyright (c) KALEIDOS INC
+ */
+
+/**
+ * delete the content directly before the caret position and this intention is
+ * not covered by another `inputType` or delete the selection with the
+ * selection collapsing to its start after the deletion.
+ *
+ * @param {InputEvent} event
+ * @param {TextEditor} editor
+ * @param {SelectionController} selectionController
+ */
+export function deleteContentBackward(event, editor, selectionController) {
+  event.preventDefault();
+  // If the editor is empty this is a no op.
+  if (editor.isEmpty) return;
+
+  // If not is collapsed AKA is a selection, then
+  // we removeSelected.
+  if (!selectionController.isCollapsed) {
+    return selectionController.removeSelected({ direction: 'backward' });
+  }
+
+  // If we're in a text node and the offset is
+  // greater than 0 (not at the start of the inline)
+  // we simple remove a character from the text.
+  if (selectionController.isTextFocus && selectionController.focusOffset > 0) {
+    return selectionController.removeBackwardText();
+
+  // If we're in a text node but we're at the end of the
+  // paragraph, we should merge the current paragraph
+  // with the following paragraph.
+  } else if (
+    selectionController.isTextFocus &&
+    selectionController.focusAtStart
+  ) {
+    return selectionController.mergeBackwardParagraph();
+
+  // If we're at an inline or a line break paragraph
+  // and there's more than one paragraph, then we should
+  // remove the next paragraph.
+  } else if (
+    selectionController.isInlineFocus ||
+    selectionController.isLineBreakFocus
+  ) {
+    return selectionController.removeBackwardParagraph();
+  }
+}