fix(discord): auto-convert markdown tables to bullet groups

Discord does not render GFM pipe tables — raw pipe characters display
as garbage text. format_message now rewrites tables into bold-heading +
bullet groups using the shared helpers.

Fixes #21168

Co-authored-by: Yashiel Sookdeo <yashiel@skyner.co.za>

plugins/platforms/discord/adapter.py

@@ -3411,13 +3411,15 @@ class DiscordAdapter(BasePlatformAdapter):
             print(f"[{self.name}] Updated DISCORD_ALLOWED_USERS with {resolved_count} resolved ID(s)")
 
     def format_message(self, content: str) -> str:
-        """
-        Format message for Discord.
+        """Format message for Discord.
 
-        Discord uses its own markdown variant.
+        Converts GFM markdown tables to bullet-list groups since Discord
+        does not render pipe tables natively.
         """
-        # Discord markdown is fairly standard, no special escaping needed
-        return content
+        if not content:
+            return content
+        from gateway.platforms.helpers import convert_table_to_bullets
+        return convert_table_to_bullets(content)
 
     async def _run_simple_slash(
         self,

tests/gateway/test_discord_format.py

@@ -0,0 +1,58 @@
+"""Discord format_message: tables converted to bullet groups."""
+
+import types
+import sys
+
+
+def _make_discord_adapter():
+    """Construct a DiscordAdapter with discord.py stubbed out."""
+    fake_discord = types.ModuleType("discord")
+    fake_discord.Intents = type("Intents", (), {"default": classmethod(lambda cls: cls())})
+    fake_discord.Message = object
+    fake_ext = types.ModuleType("discord.ext")
+    fake_commands = types.ModuleType("discord.ext.commands")
+    fake_ext.commands = fake_commands
+    fake_discord.ext = fake_ext
+    sys.modules.setdefault("discord", fake_discord)
+    sys.modules.setdefault("discord.ext", fake_ext)
+    sys.modules.setdefault("discord.ext.commands", fake_commands)
+
+    from plugins.platforms.discord.adapter import DiscordAdapter
+    adapter = object.__new__(DiscordAdapter)
+    return adapter
+
+
+class TestDiscordFormatMessage:
+
+    def test_table_converted_to_bullets(self):
+        adapter = _make_discord_adapter()
+        text = (
+            "Results:\n\n"
+            "| Name | Score |\n"
+            "|------|-------|\n"
+            "| Alice | 95   |\n"
+            "| Bob   | 80   |\n"
+            "\nDone."
+        )
+        out = adapter.format_message(text)
+        assert "**Alice**" in out
+        assert "• Score: 95" in out
+        assert "**Bob**" in out
+        assert "• Score: 80" in out
+        assert out.startswith("Results:")
+        assert out.rstrip().endswith("Done.")
+        assert "|---" not in out
+
+    def test_plain_text_unchanged(self):
+        adapter = _make_discord_adapter()
+        text = "Hello world, no tables here."
+        assert adapter.format_message(text) == text
+
+    def test_code_block_table_unchanged(self):
+        adapter = _make_discord_adapter()
+        text = "```\n| a | b |\n|---|---|\n| 1 | 2 |\n```"
+        assert adapter.format_message(text) == text
+
+    def test_empty_string(self):
+        adapter = _make_discord_adapter()
+        assert adapter.format_message("") == ""