fix: escape accidental Telegram blockquote markers in MarkdownV2 output (#524)

Co-authored-by: Letta Code <noreply@letta.com>

src/channels/telegram-format.test.ts

@@ -40,4 +40,47 @@ describe('markdownToTelegramV2', () => {
     const result = await markdownToTelegramV2('Just some plain text');
     expect(result).toContain('Just some plain text');
   });
+
+  it('preserves intentional markdown blockquotes', async () => {
+    const result = await markdownToTelegramV2('> got annexed by the relationship problem.');
+    expect(result).toContain('> got annexed by the relationship problem');
+  });
+
+  it('does not alter greater-than signs in the middle of a line', async () => {
+    const result = await markdownToTelegramV2('2 > 1');
+    expect(result).toContain('2 \\> 1');
+  });
+
+  it('preserves greater-than signs inside fenced code blocks', async () => {
+    const result = await markdownToTelegramV2('```\n> code\n```');
+    expect(result).toContain('```\n> code\n```');
+  });
+
+  it('preserves mixed multiline content with blockquotes and plain text', async () => {
+    const result = await markdownToTelegramV2('> quote\nnormal line\n2 > 1');
+    expect(result).toContain('> quote');
+    expect(result).toContain('normal line');
+    expect(result).toContain('2 \\> 1');
+  });
+
+  it('preserves indented blockquotes', async () => {
+    const result = await markdownToTelegramV2('  > indented quote');
+    expect(result).toContain('> indented quote');
+    expect(result).not.toContain('\\> indented quote');
+  });
+
+  it('preserves nested blockquotes', async () => {
+    const result = await markdownToTelegramV2('>> nested');
+    expect(result).toContain('> > nested');
+  });
+
+  it('preserves greater-than signs in fenced code blocks with language and multiple lines', async () => {
+    const result = await markdownToTelegramV2('```ts\n> one\n> two\nconst x = 1 > 0\n```');
+    expect(result).toContain('```\n> one\n> two\nconst x = 1 > 0\n```');
+  });
+
+  it('preserves greater-than signs in inline code spans', async () => {
+    const result = await markdownToTelegramV2('Use `a > b` inline');
+    expect(result).toContain('`a > b`');
+  });
 });

src/channels/telegram-format.ts

@@ -16,7 +16,7 @@ export async function markdownToTelegramV2(markdown: string): Promise<string> {
   try {
     // Dynamic import to handle ESM module
     const telegramifyMarkdown = (await import('telegramify-markdown')).default;
-    // Use 'keep' strategy to preserve blockquotes (>) and other unsupported elements
+    // Use 'keep' strategy for broad markdown support, including blockquotes.
     return telegramifyMarkdown(markdown, 'keep');
   } catch (e) {
     log.error('Markdown conversion failed, using escape fallback:', e);