Record uncaught errors and add command to display them

6 files changed, 79 insertions, 12 deletions

diff --git a/slack/commands.py b/slack/commands.py
index 60fd5d9..5e6e40c 100644
--- a/slack/commands.py
+++ b/slack/commands.py
@@ -8,8 +8,9 @@ from typing import Callable, Dict, List, Optional, Tuple
 
 import weechat
 
+from slack.error import UncaughtError
 from slack.log import print_error
-from slack.python_compatibility import removeprefix, removesuffix
+from slack.python_compatibility import format_exception, removeprefix, removesuffix
 from slack.shared import shared
 from slack.slack_conversation import (
     SlackConversation,
@@ -261,7 +262,14 @@ def command_slack_workspace_del(
     )
 
 
-@weechat_command("tasks|buffer")
+def print_uncaught_error(error: UncaughtError, detailed: bool = False):
+    weechat.prnt("", f"  {error.id} ({error.time}): {error.exception}")
+    if detailed:
+        for line in format_exception(error.exception):
+            weechat.prnt("", f"  {line}")
+
+
+@weechat_command("tasks|buffer|errors|error", split_all_args=True)
 def command_slack_debug(
     buffer: str, args: List[str], options: Dict[str, Optional[str]]
 ):
@@ -274,6 +282,36 @@ def command_slack_debug(
         conversation = get_conversation_from_buffer_pointer(buffer)
         if conversation:
             weechat.prnt("", f"Conversation id: {conversation.id}")
+    elif args[0] == "errors":
+        num_arg = int(args[1]) if len(args) > 1 and args[1].isdecimal() else 5
+        num = min(num_arg, len(shared.uncaught_errors))
+        weechat.prnt("", f"Last {num} errors:")
+        for error in shared.uncaught_errors[-num:]:
+            print_uncaught_error(error)
+    elif args[0] == "error":
+        if len(args) > 1:
+            if args[1].isdecimal() and args[1] != "0":
+                num = int(args[1])
+                if num > len(shared.uncaught_errors):
+                    print_error(
+                        f"Only {len(shared.uncaught_errors)} error(s) have occurred"
+                    )
+                    return
+                error = shared.uncaught_errors[-num]
+            else:
+                errors = [e for e in shared.uncaught_errors if e.id == args[1]]
+                if not errors:
+                    print_error(f"Error {args[1]} not found")
+                    return
+                error = errors[0]
+            weechat.prnt("", f"Error {error.id}:")
+        elif not shared.uncaught_errors:
+            weechat.prnt("", "No errors have occurred")
+            return
+        else:
+            error = shared.uncaught_errors[-1]
+            weechat.prnt("", "Last error:")
+        print_uncaught_error(error, True)
 
 
 def completion_slack_workspaces_cb(
diff --git a/slack/error.py b/slack/error.py
index a92626d..8817759 100644
--- a/slack/error.py
+++ b/slack/error.py
@@ -1,6 +1,11 @@
 from __future__ import annotations
 
+from dataclasses import dataclass, field
+from datetime import datetime
 from typing import TYPE_CHECKING, Dict, Mapping, Sequence, Union
+from uuid import uuid4
+
+from slack.shared import shared
 
 if TYPE_CHECKING:
     from slack_api.slack_common import SlackErrorResponse
@@ -55,18 +60,32 @@ class SlackError(Exception):
         self.error = error
 
 
-def format_exception(e: BaseException):
+@dataclass
+class UncaughtError:
+    id: str = field(init=False)
+    exception: BaseException
+
+    def __post_init__(self):
+        self.id = str(uuid4())
+        self.time = datetime.now()
+
+
+def store_and_format_exception(e: BaseException):
+    uncaught_error = UncaughtError(e)
+    shared.uncaught_errors.append(uncaught_error)
+    stack_msg = f"(run /slack debug error {uncaught_error.id} for stack trace)"
+
     if isinstance(e, HttpError):
         return (
             f"Error calling URL {e.url}: return code: {e.return_code}, "
-            f"http status code: {e.http_status_code}, error: {e.error}"
+            f"http status code: {e.http_status_code}, error: {e.error} {stack_msg}"
         )
     elif isinstance(e, SlackApiError):
         return (
             f"Error from Slack API method {e.method} with params {e.params} for workspace "
-            f"{e.workspace.name}: {e.response}"
+            f"{e.workspace.name}: {e.response} {stack_msg}"
         )
     elif isinstance(e, SlackError):
-        return f"Error occurred in workspace {e.workspace.name}: {e.error}"
+        return f"Error occurred in workspace {e.workspace.name}: {e.error} {stack_msg}"
     else:
-        return f"Unknown error occurred: {e.__class__.__name__}: {e}"
+        return f"Unknown error occurred: {e.__class__.__name__}: {e} {stack_msg}"
diff --git a/slack/log.py b/slack/log.py
index b132c0e..4b8bbe1 100644
--- a/slack/log.py
+++ b/slack/log.py
@@ -5,7 +5,7 @@ from typing import Set
 
 import weechat
 
-from slack.error import format_exception
+from slack.error import store_and_format_exception
 from slack.shared import shared
 
 printed_exceptions: Set[BaseException] = set()
@@ -27,7 +27,7 @@ def print_error(message: str):
 
 def print_exception_once(e: BaseException):
     if e not in printed_exceptions:
-        print_error(format_exception(e))
+        print_error(store_and_format_exception(e))
         printed_exceptions.add(e)
 
 
diff --git a/slack/python_compatibility.py b/slack/python_compatibility.py
index 1590894..e96b8af 100644
--- a/slack/python_compatibility.py
+++ b/slack/python_compatibility.py
@@ -1,3 +1,7 @@
+import traceback
+from typing import List
+
+
 # Copied from https://peps.python.org/pep-0616/ for support for Python < 3.9
 def removeprefix(self: str, prefix: str) -> str:
     if self.startswith(prefix):
@@ -12,3 +16,7 @@ def removesuffix(self: str, suffix: str) -> str:
         return self[: -len(suffix)]
     else:
         return self[:]
+
+
+def format_exception(exc: BaseException) -> List[str]:
+    return traceback.format_exception(type(exc), exc, exc.__traceback__)
diff --git a/slack/shared.py b/slack/shared.py
index 31ff748..8dbac1a 100644
--- a/slack/shared.py
+++ b/slack/shared.py
@@ -5,6 +5,7 @@ from typing import TYPE_CHECKING, Callable, Dict, List, Union
 
 if TYPE_CHECKING:
     from slack.config import SlackConfig
+    from slack.error import UncaughtError
     from slack.slack_workspace import SlackWorkspace
     from slack.task import Future, Task
 
@@ -22,6 +23,7 @@ class Shared:
         self.active_futures: Dict[str, Future[object]] = {}
         self.workspaces: Dict[str, SlackWorkspace] = {}
         self.config: SlackConfig
+        self.uncaught_errors: List[UncaughtError] = []
 
 
 shared = Shared()
diff --git a/slack/task.py b/slack/task.py
index b812387..3fafa2e 100644
--- a/slack/task.py
+++ b/slack/task.py
@@ -20,7 +20,7 @@ from uuid import uuid4
 
 import weechat
 
-from slack.error import format_exception
+from slack.error import store_and_format_exception
 from slack.log import print_error
 from slack.shared import shared
 from slack.util import get_callback_name
@@ -212,7 +212,7 @@ def task_runner(task: Task[Any]):
             if not task.exception_read():
                 print_error(
                     f"{task} was never awaited and failed with: "
-                    f"{format_exception(exception)}"
+                    f"{store_and_format_exception(exception)}"
                 )
         failed_tasks.clear()
 
@@ -226,7 +226,7 @@ def create_task(coroutine: Coroutine[Future[Any], Any, T]) -> Task[T]:
 def _async_task_done(task: Task[object]):
     exception = task.exception()
     if exception:
-        print_error(f"{task} failed with: {format_exception(exception)}")
+        print_error(f"{task} failed with: {store_and_format_exception(exception)}")
 
 
 def run_async(coroutine: Coroutine[Future[Any], Any, Any]) -> None: