fix(blocks): newline handling in MixTextAdapter and paste middleware (#…

…8821)

Fix #8816

Also related to #8575

Revert and adjust newline insertion logic to improve text handling in the MixTextAdapter and clipboard paste functionality.

packages/blocks/src/_common/adapters/mix-text.ts

@@ -83,24 +83,24 @@ export class MixTextAdapter extends BaseAdapter<MixText> {
       const text = (o.node.props.text ?? { delta: [] }) as {
         delta: DeltaInsert[];
       };
+      if (buffer.length > 0) {
+        buffer += '\n';
+      }
       switch (o.node.flavour) {
         case 'affine:code': {
           buffer += text.delta.map(delta => delta.insert).join('');
-          buffer += '\n';
           break;
         }
         case 'affine:paragraph': {
           buffer += text.delta.map(delta => delta.insert).join('');
-          buffer += '\n';
           break;
         }
         case 'affine:list': {
           buffer += text.delta.map(delta => delta.insert).join('');
-          buffer += '\n';
           break;
         }
         case 'affine:divider': {
-          buffer += '---\n';
+          buffer += '---';
           break;
         }
       }

packages/blocks/src/root-block/clipboard/middlewares/paste.ts

@@ -114,12 +114,9 @@ class PasteTr {
     this.snapshot.content.forEach((blockSnapshot, i) => {
       if (blockSnapshot.props.text) {
         const text = this._textFromSnapshot(blockSnapshot);
-        if (i != 0 && i !== this.snapshot.content.length - 1) {
+        if (i > 0) {
           deltas.push({ insert: '\n' });
         }
-        if (i != 0 && i === this.snapshot.content.length - 1) {
-          this.lastIndex -= 1;
-        }
         deltas.push(...text.delta);
       }
     });

tests/snapshots/clipboard/clipboard.spec.ts/clipboard-copy-nested-items-clipboard.md

@@ -1,2 +1,2 @@
 bc
-d
+d

tests/snapshots/clipboard/clipboard.spec.ts/clipboard-copy-nested-items-clipboard2.md

@@ -1,2 +1,2 @@
 hi
-j
+j

tests/snapshots/clipboard/list.spec.ts/copy-a-nested-list-by-clicking-button-the-clipboard-data-should-be-complete-clipboard.md

@@ -1,3 +1,3 @@
 aaa
 bbb
-ccc
+ccc