Show size and a draft indicator in snippet-library rows

src/core/snippet.test.ts

@@ -2,10 +2,12 @@ import { describe, expect, test } from 'vitest';
 import {
   CURRENT_SNIPPET_VERSION,
   createSnippet,
+  formatSnippetSize,
   generateSnippetName,
   hasUnpublishedChanges,
   SAMPLE_SPEC,
   sampleSpecText,
+  snippetSizeBytes,
 } from './snippet';
 
 describe('createSnippet', () => {
@@ -72,3 +74,36 @@ describe('hasUnpublishedChanges', () => {
     expect(hasUnpublishedChanges({ ...s, draftSpec: s.spec + ' ' })).toBe(true);
   });
 });
+
+describe('snippetSizeBytes', () => {
+  test('measures the draft as UTF-8 byte length, not character count', () => {
+    const s = createSnippet({ spec: 'abc' });
+    expect(snippetSizeBytes(s)).toBe(3);
+    // A 3-character string of multibyte glyphs is more than 3 bytes.
+    expect(snippetSizeBytes({ ...s, draftSpec: '€€€' })).toBe(9);
+  });
+
+  test('reflects the working draft, not the published spec', () => {
+    const s = createSnippet({ spec: 'ab' });
+    expect(snippetSizeBytes({ ...s, draftSpec: 'abcdef' })).toBe(6);
+  });
+});
+
+describe('formatSnippetSize', () => {
+  test('omits the size under ~1 KB (spec §02 clutter rule)', () => {
+    expect(formatSnippetSize(0)).toBeNull();
+    expect(formatSnippetSize(512)).toBeNull();
+    expect(formatSnippetSize(1023)).toBeNull();
+  });
+
+  test('shows whole KB at and above the threshold', () => {
+    expect(formatSnippetSize(1024)).toBe('1 KB');
+    expect(formatSnippetSize(2048)).toBe('2 KB');
+    expect(formatSnippetSize(1536)).toBe('2 KB'); // rounds to nearest KB
+  });
+
+  test('rolls over to MB for large payloads', () => {
+    expect(formatSnippetSize(1024 * 1024)).toBe('1 MB');
+    expect(formatSnippetSize(3 * 1024 * 1024)).toBe('3 MB');
+  });
+});