fix: improve editor block controls

src/utils/codeBlockLanguage.test.ts

@@ -0,0 +1,44 @@
+import { describe, expect, it } from 'vitest'
+import { inferCodeBlockLanguage, inferCodeBlockLanguages } from './codeBlockLanguage'
+
+describe('code block language inference', () => {
+  it('detects TypeScript interface snippets', () => {
+    expect(inferCodeBlockLanguage([
+      'interface VaultEntry {',
+      '  path: string;',
+      '  title: string;',
+      '  status: string | null;',
+      '}',
+    ].join('\n'))).toBe('typescript')
+  })
+
+  it('detects JSON before JavaScript-like punctuation', () => {
+    expect(inferCodeBlockLanguage('{ "id": "Demo", "count": 1 }')).toBe('json')
+  })
+
+  it('preserves explicit user-selected code block languages', () => {
+    const blocks = inferCodeBlockLanguages([{
+      type: 'codeBlock',
+      props: { language: 'python' },
+      content: [{ type: 'text', text: 'interface Demo { value: string }' }],
+      children: [],
+    }])
+
+    expect(blocks[0]).toMatchObject({
+      props: { language: 'python' },
+    })
+  })
+
+  it('updates unlabeled code blocks from plain text to the inferred language', () => {
+    const blocks = inferCodeBlockLanguages([{
+      type: 'codeBlock',
+      props: { language: 'text' },
+      content: [{ type: 'text', text: 'const total: number = 1' }],
+      children: [],
+    }])
+
+    expect(blocks[0]).toMatchObject({
+      props: { language: 'typescript' },
+    })
+  })
+})