From 48b472163f9f496e33c96518216585d243dff86a Mon Sep 17 00:00:00 2001
From: Daniel Lautzenheiser <lautzd@gmail.com>
Date: Thu, 14 Sep 2023 10:14:42 -0400
Subject: [PATCH] fix: delete code block on backspace when code block is empty
 (#877)

---
 .../nodes/code-block/CodeBlockElement.tsx           | 13 +++++++++++--
 .../components/nodes/code-block/CodeBlockFrame.tsx  | 13 ++++++++++++-
 .../plugins/code-block/createCodeBlockPlugin.ts     |  4 ++--
 3 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/packages/core/src/widgets/markdown/plate/components/nodes/code-block/CodeBlockElement.tsx b/packages/core/src/widgets/markdown/plate/components/nodes/code-block/CodeBlockElement.tsx
index 71740240..8f1d6a9b 100644
--- a/packages/core/src/widgets/markdown/plate/components/nodes/code-block/CodeBlockElement.tsx
+++ b/packages/core/src/widgets/markdown/plate/components/nodes/code-block/CodeBlockElement.tsx
@@ -1,4 +1,4 @@
-import { findNodePath, setNodes } from '@udecode/plate';
+import { findNodePath, focusEditor, removeNodes, setNodes } from '@udecode/plate';
 import React, { useCallback, useEffect, useMemo, useRef, useState } from 'react';
 import Frame from 'react-frame-component';
 
@@ -32,15 +32,24 @@ const CodeBlockElement: FC<PlateRenderElementProps<MdValue, MdCodeBlockElement>>
     [editor, element],
   );
 
+  const handleDelete = useCallback(() => {
+    const path = findNodePath(editor, element);
+    path && removeNodes(editor, { at: path });
+    focusEditor(editor);
+  }, [editor, element]);
+
   const receiveMessage = useCallback(
     (event: MessageEvent) => {
       switch (event.data.message) {
         case `code_block_${id}_onChange`:
           handleChange(event.data.value);
           break;
+        case `code_block_${id}_delete`:
+          handleDelete();
+          break;
       }
     },
-    [handleChange, id],
+    [handleChange, handleDelete, id],
   );
 
   useWindowEvent('message', receiveMessage);
diff --git a/packages/core/src/widgets/markdown/plate/components/nodes/code-block/CodeBlockFrame.tsx b/packages/core/src/widgets/markdown/plate/components/nodes/code-block/CodeBlockFrame.tsx
index 47c828ac..7ab4d21f 100644
--- a/packages/core/src/widgets/markdown/plate/components/nodes/code-block/CodeBlockFrame.tsx
+++ b/packages/core/src/widgets/markdown/plate/components/nodes/code-block/CodeBlockFrame.tsx
@@ -7,8 +7,9 @@ import React, { useCallback, useMemo } from 'react';
 import { useFrame } from 'react-frame-component';
 
 import languages from '@staticcms/code/data/languages';
+import { isEmpty } from '@staticcms/core/lib/util/string.util';
 
-import type { FC } from 'react';
+import type { FC, KeyboardEvent } from 'react';
 
 export interface CodeBlockFrameProps {
   id: string;
@@ -61,6 +62,15 @@ const CodeBlockFrame: FC<CodeBlockFrameProps> = ({ id, lang, code, theme }) => {
     window?.parent.postMessage({ message: `code_block_${id}_onBlur` });
   }, [id, window?.parent]);
 
+  const handleKeyDown = useCallback(
+    (event: KeyboardEvent) => {
+      if (event.key === 'Backspace' && isEmpty(code)) {
+        window?.parent.postMessage({ message: `code_block_${id}_delete` });
+      }
+    },
+    [code, id, window?.parent],
+  );
+
   return (
     <CodeMirror
       value={code}
@@ -68,6 +78,7 @@ const CodeBlockFrame: FC<CodeBlockFrameProps> = ({ id, lang, code, theme }) => {
       onFocus={handleFocus}
       onBlur={handleBlur}
       onChange={handleChange}
+      onKeyDown={handleKeyDown}
       extensions={extensions}
       theme={theme}
     />
diff --git a/packages/core/src/widgets/markdown/plate/plugins/code-block/createCodeBlockPlugin.ts b/packages/core/src/widgets/markdown/plate/plugins/code-block/createCodeBlockPlugin.ts
index b7a41aaf..fcb3a55f 100644
--- a/packages/core/src/widgets/markdown/plate/plugins/code-block/createCodeBlockPlugin.ts
+++ b/packages/core/src/widgets/markdown/plate/plugins/code-block/createCodeBlockPlugin.ts
@@ -3,12 +3,12 @@ import { ELEMENT_CODE_BLOCK, createPluginFactory } from '@udecode/plate';
 import deserializeHtmlCodeBlock from './deserializeHtmlCodeBlock';
 
 import type { MdValue } from '@staticcms/markdown';
-import type { HotkeyPlugin, PlateEditor } from '@udecode/plate';
+import type { CodeBlockPlugin, PlateEditor } from '@udecode/plate';
 
 /**
  * Enables support for pre-formatted code blocks.
  */
-const createCodeBlockPlugin = createPluginFactory<HotkeyPlugin, MdValue, PlateEditor<MdValue>>({
+const createCodeBlockPlugin = createPluginFactory<CodeBlockPlugin, MdValue, PlateEditor<MdValue>>({
   key: ELEMENT_CODE_BLOCK,
   isElement: true,
   deserializeHtml: deserializeHtmlCodeBlock,