Add mention parsing and command extraction logic

Author: joshuadavidthomas

src/django_github_app/commands.py

@@ -1,6 +1,8 @@
 from __future__ import annotations
 
+import re
 from enum import Enum
+from typing import Any
 from typing import NamedTuple
 
 
@@ -39,3 +41,51 @@ def all_events(cls) -> list[EventAction]:
             )
         )
 
+
+class MentionMatch(NamedTuple):
+    mention: str
+    command: str | None
+
+
+CODE_BLOCK_PATTERN = re.compile(r"```[\s\S]*?```", re.MULTILINE)
+INLINE_CODE_PATTERN = re.compile(r"`[^`]+`")
+QUOTE_PATTERN = re.compile(r"^\s*>.*$", re.MULTILINE)
+
+
+def parse_mentions(text: str, username: str) -> list[MentionMatch]:
+    if not text:
+        return []
+
+    text = CODE_BLOCK_PATTERN.sub(lambda m: " " * len(m.group(0)), text)
+    text = INLINE_CODE_PATTERN.sub(lambda m: " " * len(m.group(0)), text)
+    text = QUOTE_PATTERN.sub(lambda m: " " * len(m.group(0)), text)
+
+    username_pattern = re.compile(
+        rf"(?:^|(?<=\s))(@{re.escape(username)})(?:\s+([\w\-?]+))?(?=\s|$|[^\w\-])",
+        re.MULTILINE | re.IGNORECASE,
+    )
+
+    mentions: list[MentionMatch] = []
+    for match in username_pattern.finditer(text):
+        mention = match.group(1)  # @username
+        command = match.group(2)  # optional command
+        mentions.append(
+            MentionMatch(mention=mention, command=command.lower() if command else None)
+        )
+
+    return mentions
+
+
+def check_event_for_mention(
+    event: dict[str, Any], command: str | None, username: str
+) -> bool:
+    comment = event.get("comment", {}).get("body", "")
+    mentions = parse_mentions(comment, username)
+
+    if not mentions:
+        return False
+
+    if not command:
+        return True
+
+    return any(mention.command == command.lower() for mention in mentions)

src/django_github_app/routing.py

@@ -15,6 +15,7 @@
 
 from ._typing import override
 from .commands import CommandScope
+from .commands import check_event_for_mention
 
 AsyncCallback = Callable[..., Awaitable[None]]
 SyncCallback = Callable[..., None]
@@ -76,8 +77,12 @@ def decorator(func: CB) -> CB:
             async def async_wrapper(
                 event: sansio.Event, *args: Any, **wrapper_kwargs: Any
             ) -> None:
-                # TODO: Parse comment body for mentions
-                # TODO: If command specified, check if it matches
+                # TODO: Get actual bot username from installation/app data
+                username = "bot"  # Placeholder
+
+                if not check_event_for_mention(event.data, command, username):
+                    return
+
                 # TODO: Check permissions
                 # For now, just call through
                 await func(event, *args, **wrapper_kwargs)  # type: ignore[func-returns-value]
@@ -86,8 +91,12 @@ async def async_wrapper(
             def sync_wrapper(
                 event: sansio.Event, *args: Any, **wrapper_kwargs: Any
             ) -> None:
-                # TODO: Parse comment body for mentions
-                # TODO: If command specified, check if it matches
+                # TODO: Get actual bot username from installation/app data
+                username = "bot"  # Placeholder
+
+                if not check_event_for_mention(event.data, command, username):
+                    return
+
                 # TODO: Check permissions
                 # For now, just call through
                 func(event, *args, **wrapper_kwargs)
@@ -104,7 +113,9 @@ def sync_wrapper(
 
             events = scope.get_events() if scope else CommandScope.all_events()
             for event_action in events:
-                self.add(wrapper, event_action.event, action=event_action.action, **kwargs)
+                self.add(
+                    wrapper, event_action.event, action=event_action.action, **kwargs
+                )
 
             return func
 

tests/test_commands.py

@@ -0,0 +1,196 @@
+from __future__ import annotations
+
+from django_github_app.commands import check_event_for_mention
+from django_github_app.commands import parse_mentions
+
+
+class TestParseMentions:
+    def test_simple_mention_with_command(self):
+        text = "@mybot help"
+        mentions = parse_mentions(text, "mybot")
+
+        assert len(mentions) == 1
+        assert mentions[0].mention == "@mybot"
+        assert mentions[0].command == "help"
+
+    def test_mention_without_command(self):
+        text = "@mybot"
+        mentions = parse_mentions(text, "mybot")
+
+        assert len(mentions) == 1
+        assert mentions[0].mention == "@mybot"
+        assert mentions[0].command is None
+
+    def test_case_insensitive_matching(self):
+        text = "@MyBot help"
+        mentions = parse_mentions(text, "mybot")
+
+        assert len(mentions) == 1
+        assert mentions[0].mention == "@MyBot"
+        assert mentions[0].command == "help"
+
+    def test_command_case_normalization(self):
+        text = "@mybot HELP"
+        mentions = parse_mentions(text, "mybot")
+
+        assert len(mentions) == 1
+        assert mentions[0].command == "help"
+
+    def test_multiple_mentions(self):
+        text = "@mybot help and then @mybot deploy"
+        mentions = parse_mentions(text, "mybot")
+
+        assert len(mentions) == 2
+        assert mentions[0].command == "help"
+        assert mentions[1].command == "deploy"
+
+    def test_ignore_other_mentions(self):
+        text = "@otheruser help @mybot deploy @someone else"
+        mentions = parse_mentions(text, "mybot")
+
+        assert len(mentions) == 1
+        assert mentions[0].command == "deploy"
+
+    def test_mention_in_code_block(self):
+        text = """
+        Here's some text
+        ```
+        @mybot help
+        ```
+        @mybot deploy
+        """
+        mentions = parse_mentions(text, "mybot")
+
+        assert len(mentions) == 1
+        assert mentions[0].command == "deploy"
+
+    def test_mention_in_inline_code(self):
+        text = "Use `@mybot help` for help, or just @mybot deploy"
+        mentions = parse_mentions(text, "mybot")
+
+        assert len(mentions) == 1
+        assert mentions[0].command == "deploy"
+
+    def test_mention_in_quote(self):
+        text = """
+        > @mybot help
+        @mybot deploy
+        """
+        mentions = parse_mentions(text, "mybot")
+
+        assert len(mentions) == 1
+        assert mentions[0].command == "deploy"
+
+    def test_empty_text(self):
+        mentions = parse_mentions("", "mybot")
+
+        assert mentions == []
+
+    def test_none_text(self):
+        mentions = parse_mentions(None, "mybot")
+
+        assert mentions == []
+
+    def test_mention_at_start_of_line(self):
+        text = "@mybot help"
+        mentions = parse_mentions(text, "mybot")
+
+        assert len(mentions) == 1
+        assert mentions[0].command == "help"
+
+    def test_mention_in_middle_of_text(self):
+        text = "Hey @mybot help me"
+        mentions = parse_mentions(text, "mybot")
+
+        assert len(mentions) == 1
+        assert mentions[0].command == "help"
+
+    def test_mention_with_punctuation_after(self):
+        text = "@mybot help!"
+        mentions = parse_mentions(text, "mybot")
+
+        assert len(mentions) == 1
+        assert mentions[0].command == "help"
+
+    def test_hyphenated_username(self):
+        text = "@my-bot help"
+        mentions = parse_mentions(text, "my-bot")
+
+        assert len(mentions) == 1
+        assert mentions[0].mention == "@my-bot"
+        assert mentions[0].command == "help"
+
+    def test_underscore_username(self):
+        text = "@my_bot help"
+        mentions = parse_mentions(text, "my_bot")
+
+        assert len(mentions) == 1
+        assert mentions[0].mention == "@my_bot"
+        assert mentions[0].command == "help"
+
+    def test_no_space_after_mention(self):
+        text = "@mybot, please help"
+        mentions = parse_mentions(text, "mybot")
+
+        assert len(mentions) == 1
+        assert mentions[0].command is None
+
+    def test_multiple_spaces_before_command(self):
+        text = "@mybot    help"
+        mentions = parse_mentions(text, "mybot")
+
+        assert len(mentions) == 1
+        assert mentions[0].command == "help"
+
+    def test_hyphenated_command(self):
+        text = "@mybot async-test"
+        mentions = parse_mentions(text, "mybot")
+
+        assert len(mentions) == 1
+        assert mentions[0].command == "async-test"
+
+    def test_special_character_command(self):
+        text = "@mybot ?"
+        mentions = parse_mentions(text, "mybot")
+
+        assert len(mentions) == 1
+        assert mentions[0].command == "?"
+
+
+class TestCheckMentionMatches:
+    def test_match_with_command(self):
+        event = {"comment": {"body": "@bot help"}}
+
+        assert check_event_for_mention(event, "help", "bot") is True
+        assert check_event_for_mention(event, "deploy", "bot") is False
+
+    def test_match_without_command(self):
+        event = {"comment": {"body": "@bot help"}}
+
+        assert check_event_for_mention(event, None, "bot") is True
+
+        event = {"comment": {"body": "no mention here"}}
+
+        assert check_event_for_mention(event, None, "bot") is False
+
+    def test_no_comment_body(self):
+        event = {}
+
+        assert check_event_for_mention(event, "help", "bot") is False
+
+        event = {"comment": {}}
+
+        assert check_event_for_mention(event, "help", "bot") is False
+
+    def test_case_insensitive_command_match(self):
+        event = {"comment": {"body": "@bot HELP"}}
+
+        assert check_event_for_mention(event, "help", "bot") is True
+        assert check_event_for_mention(event, "HELP", "bot") is True
+
+    def test_multiple_mentions(self):
+        event = {"comment": {"body": "@bot help @bot deploy"}}
+
+        assert check_event_for_mention(event, "help", "bot") is True
+        assert check_event_for_mention(event, "deploy", "bot") is True
+        assert check_event_for_mention(event, "test", "bot") is False

tests/test_routing.py

@@ -216,7 +216,8 @@ def help_command(event, *args, **kwargs):
 
         assert handler_called
 
-    def test_multiple_decorators_on_same_function(self, test_router):
+    @pytest.mark.parametrize("comment", ["@bot help", "@bot h", "@bot ?"])
+    def test_multiple_decorators_on_same_function(self, comment, test_router):
         call_count = 0
 
         @test_router.mention(command="help")
@@ -227,26 +228,14 @@ def help_command(event, *args, **kwargs):
             call_count += 1
             return f"help called {call_count} times"
 
-        event1 = sansio.Event(
-            {"action": "created", "comment": {"body": "@bot help"}},
+        event = sansio.Event(
+            {"action": "created", "comment": {"body": comment}},
             event="issue_comment",
             delivery_id="123",
         )
-        test_router.dispatch(event1, None)
-
-        assert call_count == 3
-
-        call_count = 0
-        event2 = sansio.Event(
-            {"action": "created", "comment": {"body": "@bot h"}},
-            event="issue_comment",
-            delivery_id="124",
-        )
-        test_router.dispatch(event2, None)
-
-        assert call_count == 3
+        test_router.dispatch(event, None)
 
-        # This behavior will change once we implement command parsing
+        assert call_count == 1
 
     def test_async_mention_handler(self, test_router):
         handler_called = False