fix(slack): keep fenced markdown tables intact in _to_mrkdwn

nanobot/channels/slack/runtime.py

@@ -701,7 +701,16 @@ class SlackChannel(BaseChannel):
         """Convert Markdown to Slack mrkdwn, including tables."""
         if not text:
             return ""
+        code_blocks: list[str] = []
+
+        def _save_fence(m: re.Match) -> str:
+            code_blocks.append(m.group(0))
+            return f"\x00CB{len(code_blocks) - 1}\x00"
+
+        text = cls._CODE_FENCE_RE.sub(_save_fence, text)
         text = cls._TABLE_RE.sub(cls._convert_table, text)
+        for i, block in enumerate(code_blocks):
+            text = text.replace(f"\x00CB{i}\x00", block)
         return cls._fixup_mrkdwn(slackify_markdown(text)).rstrip("\n")
 
     @classmethod

nanobot/channels/slack/tests/test_slack_channel.py

@@ -714,3 +714,19 @@ def test_group_require_mention_accepts_camel_case_alias() -> None:
     )
     assert config.group_require_mention is True
     assert config.group_allow_from == ["C_OK"]
+
+
+def test_to_mrkdwn_keeps_fenced_markdown_tables_intact() -> None:
+    text = "Intro\n\n```\n| a | b |\n| - | - |\n| 1 | 2 |\n```\n\nOutro"
+    out = SlackChannel._to_mrkdwn(text)
+
+    assert "```\n| a | b |\n| - | - |\n| 1 | 2 |\n```" in out
+    assert "**a**: 1" not in out
+    assert "*a*: 1" not in out
+
+
+def test_to_mrkdwn_still_converts_unfenced_markdown_tables() -> None:
+    out = SlackChannel._to_mrkdwn("| a | b |\n| - | - |\n| 1 | 2 |")
+
+    assert "| a | b |" not in out
+    assert "a" in out and "1" in out and "b" in out and "2" in out