From 3e7e81516b1b5e0a45b7dc84a0f38df2303a34df Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20Hamburger=20Gr=C3=B8ngaard?=
 <christian.groengaard@sanity.io>
Date: Thu, 31 Oct 2024 09:49:54 +0100
Subject: [PATCH] fix(editor): handle edge case with deleting empty text blocks
 next to block objects

---
 .../src/editor/behavior/behavior.core.ts      | 97 ++++++++++++++++++-
 1 file changed, 95 insertions(+), 2 deletions(-)

diff --git a/packages/editor/src/editor/behavior/behavior.core.ts b/packages/editor/src/editor/behavior/behavior.core.ts
index 9a4de733..4829c752 100644
--- a/packages/editor/src/editor/behavior/behavior.core.ts
+++ b/packages/editor/src/editor/behavior/behavior.core.ts
@@ -1,5 +1,13 @@
+import {isPortableTextTextBlock} from '@sanity/types'
 import {defineBehavior} from './behavior.types'
-import {getFocusBlockObject} from './behavior.utils'
+import {
+  getFocusBlockObject,
+  getFocusTextBlock,
+  getNextBlock,
+  getPreviousBlock,
+  isEmptyTextBlock,
+  selectionIsCollapsed,
+} from './behavior.utils'
 
 const softReturn = defineBehavior({
   on: 'insert soft break',
@@ -16,4 +24,89 @@ const breakingVoidBlock = defineBehavior({
   actions: [() => [{type: 'insert text block', decorators: []}]],
 })
 
-export const coreBehaviors = [softReturn, breakingVoidBlock]
+const deletingEmptyTextBlockAfterBlockObject = defineBehavior({
+  on: 'delete backward',
+  guard: ({context}) => {
+    const focusTextBlock = getFocusTextBlock(context)
+    const selectionCollapsed = selectionIsCollapsed(context)
+    const previousBlock = getPreviousBlock(context)
+
+    if (!focusTextBlock || !selectionCollapsed || !previousBlock) {
+      return false
+    }
+
+    if (
+      isEmptyTextBlock(focusTextBlock.node) &&
+      !isPortableTextTextBlock(previousBlock.node)
+    ) {
+      return {focusTextBlock, previousBlock}
+    }
+
+    return false
+  },
+  actions: [
+    (_, {focusTextBlock, previousBlock}) => [
+      {
+        type: 'delete',
+        selection: {
+          anchor: {path: focusTextBlock.path, offset: 0},
+          focus: {path: focusTextBlock.path, offset: 0},
+        },
+      },
+      {
+        type: 'select',
+        selection: {
+          anchor: {path: previousBlock.path, offset: 0},
+          focus: {path: previousBlock.path, offset: 0},
+        },
+      },
+    ],
+  ],
+})
+
+const deletingEmptyTextBlockBeforeBlockObject = defineBehavior({
+  on: 'delete forward',
+  guard: ({context}) => {
+    const focusTextBlock = getFocusTextBlock(context)
+    const selectionCollapsed = selectionIsCollapsed(context)
+    const nextBlock = getNextBlock(context)
+
+    if (!focusTextBlock || !selectionCollapsed || !nextBlock) {
+      return false
+    }
+
+    if (
+      isEmptyTextBlock(focusTextBlock.node) &&
+      !isPortableTextTextBlock(nextBlock.node)
+    ) {
+      return {focusTextBlock, nextBlock}
+    }
+
+    return false
+  },
+  actions: [
+    (_, {focusTextBlock, nextBlock}) => [
+      {
+        type: 'delete',
+        selection: {
+          anchor: {path: focusTextBlock.path, offset: 0},
+          focus: {path: focusTextBlock.path, offset: 0},
+        },
+      },
+      {
+        type: 'select',
+        selection: {
+          anchor: {path: nextBlock.path, offset: 0},
+          focus: {path: nextBlock.path, offset: 0},
+        },
+      },
+    ],
+  ],
+})
+
+export const coreBehaviors = [
+  softReturn,
+  breakingVoidBlock,
+  deletingEmptyTextBlockAfterBlockObject,
+  deletingEmptyTextBlockBeforeBlockObject,
+]