chore: enable mypy v2 pre-commit hook; fix all lint/type errors it surfaces by sidmitra · Pull Request #31 · Airbase/eventbusk

Siddharth Mitra (sidmitra) · 2026-05-13T20:44:06Z

Summary

Uncomments and upgrades the mirrors-mypy pre-commit hook from the previously disabled v0.902 stub to v2.1.0, then fixes every error surfaced by running it and the full pre-commit suite.

mypy v2 — config

8 options new in mypy v2 added to [tool.mypy] (all at their defaults). Removed show_none_errors which was deleted in v2.

Per-module ignore_missing_imports overrides added for confluent_kafka and cotyledon — neither package ships type stubs or py.typed in the mypy environment.

mypy v2 — source fixes

File	Error	Fix
`brokers/base.py`	Stale `# type: ignore` on `poll()` abstract method	Removed
`brokers/__init__.py`	`BaseProducer` not in `__all__` (`implicit_reexport=false`)	Added
`brokers/dummy.py`	Missing `return None` in `poll()` (`warn_no_return`)	Added explicit `return None`
`brokers/kafka.py`	`_consumer` typed as `CConsumer` but initialised to `None`	Annotated as `CConsumer \| None`
`brokers/kafka.py`	`commit(message=)` gets `str \| bytes \| Message \| None`, expects `Message`	`cast("CMessage", message)` after `None` check
`bus.py`	`EventJsonEncoder.default()` unannotated	Added `(self, o: Any) -> Any`
`bus.py`	`self.producer` typed as bare `None`	Annotated as `BaseProducer \| None`
`cli.py`	`super().__init__(worker_id)` passes `int`, expects `WorkerId`	`WorkerId(worker_id)` via `from cotyledon.types import WorkerId`
`cli.py`	`class Worker(cotyledon.Service)` subclasses `Any`-typed base	`# type: ignore[misc]` on class definition

pylint v4 — fixes

File	Code	Fix
`brokers/base.py`	R0917	Made `flush`/`on_delivery`/`fail_silently` keyword-only
`brokers/dummy.py`	R1711	Moved `disable-next=useless-return` to `def` line
`brokers/kafka.py`	E0712	`# pylint: disable=catching-non-exception` on `except KafkaError`
`bus.py`	R0912	`# pylint: disable=too-many-branches` on `receive()`

ruff S101 — assert replacements

assert is banned outside tests by ruff rule S101. Replaced three bare asserts in brokers/kafka.py with explicit exceptions:

Location	Replacement
`Consumer.poll` / `Consumer.ack` — consumer-not-open guard	`raise RuntimeError("Consumer is not open. Use as a context manager.")`
`Producer.produce` — value type narrowing	`raise TypeError(f"Expected str or bytes, got {type(value).__name__}")`

Message as CMessage was also moved from the runtime import to the TYPE_CHECKING block, since it is only referenced in string-form cast() calls (fixing pylint W0611 unused-import).

snyk-io · 2026-05-13T20:44:15Z

⚠️ Snyk checks are incomplete.

Status	Scan Engine	Total (0)
⚠️	Open Source Security	See details
⚠️	Licenses	See details
✅	Code Security	0 issues

💻 Catch issues earlier using the plugins for VS Code, JetBrains IDEs, Visual Studio, and Eclipse.

Uncomment and upgrade the mirrors-mypy pre-commit hook from the previously commented-out v0.902 stub to v2.1.0.

pyproject.toml: - Remove show_none_errors (dropped in mypy v2) eventbusk/brokers/base.py: - Remove stale # type: ignore on poll() and produce() abstract methods eventbusk/brokers/dummy.py: - Add missing 'return None' in Consumer.poll() eventbusk/bus.py: - Add 'from typing import Any' and annotate EventJsonEncoder.default() - Annotate self.producer as BaseProducer | None (Producer is a factory function, not a class; use the base type for the annotation) - Import BaseProducer from .brokers - Remove stale # type: ignore on event_type(**event_data) eventbusk/brokers/__init__.py: - Export BaseProducer in __all__ so bus.py import resolves cleanly

New options made explicit (all at their defaults): allow_redefinition_old = false extra_checks = false follow_untyped_imports = false no_strict_bytes = false report_deprecated_as_note = false show_error_code_links = false show_error_end = false strict_equality_for_none = false Also fix double-space typo in local_partial_types key.

pyproject.toml: - Remove suggestion-mode (dropped in pylint v4) eventbusk/brokers/__init__.py: - Add pylint: disable=invalid-name on Consumer/Producer factory aliases (PascalCase names are intentional public API, not classes) eventbusk/brokers/base.py + dummy.py + kafka.py: - Make flush/on_delivery/fail_silently keyword-only args in produce() to satisfy R0917 too-many-positional-arguments; all callers already used keyword syntax so no call-site changes needed eventbusk/brokers/dummy.py: - Move pylint: disable=useless-return to def line (R1711 is reported there); keep explicit return None to satisfy mypy warn_no_return eventbusk/brokers/kafka.py: - Add pylint: disable=catching-non-exception on except KafkaError - Add pylint: disable=bad-exception-cause on raise ProducerError from exc (KafkaError is a C-extension type; pylint can't verify its hierarchy) eventbusk/bus.py: - Annotate HooksT with TypeAlias and add inline invalid-name disable (union alias HooksT not recognised as TypeAlias by pylint naming check) - Add pylint: disable=too-many-branches on wrapper() (16 branches, limit 15) - Add public before_receive_hooks / after_receive_hooks properties tests/test_brokers.py: - Add pylint: disable=raising-non-exception on raise KafkaError(...) tests/test_bus.py: - Use public before_receive_hooks / after_receive_hooks properties - Simplify empty-list checks to 'not bus.before/after_receive_hooks' - Add pylint: disable=no-value-for-parameter on foo_processor() calls (decorator transforms signature; pylint doesn't see the wrapper)

Move inline disable comments to pylint: disable-next= on preceding line to keep lines within the 88-character flake8 limit.

Copilot

Pull request overview

This PR enables the mypy v2 pre-commit hook (upgrading from the previously commented-out stub) and updates code/config to satisfy the stricter type-checking and linting results across the project.

Changes:

Enable and pin mirrors-mypy v2.1.0 in pre-commit and update mypy/pylint configuration accordingly.
Tighten typing in the event bus and broker interfaces (e.g., producer type, JSON encoder typing, broker API signatures).
Adjust broker modules/exports to satisfy typing and lint rules.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
`pyproject.toml`	Updates mypy configuration for v2 (removes deprecated options, adds explicit new defaults).
`eventbusk/bus.py`	Adds type annotations/properties and tweaks event reconstruction / producer typing.
`eventbusk/brokers/base.py`	Updates abstract broker interfaces (removes stale ignores; adjusts produce signature).
`eventbusk/brokers/__init__.py`	Exports `BaseProducer` via `__all__` for typed imports.
`eventbusk/brokers/dummy.py`	Adds explicit `return None` in `poll()` to satisfy mypy/pylint.
`eventbusk/brokers/kafka.py`	Adds targeted pylint suppression on exception chaining line.
`.pre-commit-config.yaml`	Enables mypy hook and pins to v2.1.0.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

                            # TODO: Fix following
                            # Too many arguments for "Event"  [call-arg]
-                            event = event_type(**event_data)  # type: ignore
-                            event.event_id = event_id
+                            event = event_type(**event_data)
+                            setattr(event, "event_id", event_id)


Both packages now ship py.typed and full stubs, making the blanket # type: ignore comments on their imports unused. Removing them exposed real type errors that are fixed here: brokers/base.py: - Drop # type: ignore on 'from confluent_kafka import cimpl' brokers/kafka.py: - Drop # type: ignore on confluent_kafka import block - Import Message as CMessage and cast from typing (needed for fixes below) - _consumer: CConsumer | None = None (was missing | None) - __exit__: guard close() with 'if self._consumer is not None' - poll/ack: assert self._consumer is not None (documents context-manager invariant) - ack: cast(CMessage, message) so commit(message=) gets the right type - produce: assert isinstance(value, (str, bytes)) to narrow away cimpl.Message; CProducer.produce() only accepts str | bytes - Drop stale # pylint: disable=bad-exception-cause; pylint 4.0.5 with --extension-pkg-whitelist resolves KafkaException's hierarchy correctly cli.py: - Drop # type: ignore on 'import cotyledon' and class Worker definition - Import WorkerId from cotyledon.types; pass WorkerId(worker_id) to super().__init__() - self.name assignment: # type: ignore[misc] (intentional instance-level shadow of cotyledon.Service's ClassVar[str])

- Replace assert guards in Consumer.poll/ack with RuntimeError and in Producer.produce with TypeError (ruff S101; assert is banned outside tests) - Move `Message as CMessage` to TYPE_CHECKING block — it is only referenced in string-form cast() calls so pylint flagged it as unused - Add mypy per-module overrides (ignore_missing_imports) for confluent_kafka and cotyledon — neither ships stubs in the mypy env, contradicting the earlier PR assumption - Move `# type: ignore[misc]` from self.name assignment to the class definition line in cli.py, where mypy actually fires (subclassing Any) - Wrap long logger.exception() call in bus.py (ruff E501 / ruff-format)

Siddharth Mitra (sidmitra) · 2026-05-15T00:27:33Z

            # Trigger any available delivery report callbacks from previous produce
            self._producer.poll(0)
+            if not isinstance(value, (str, bytes)):
+                raise TypeError(f"Expected str or bytes, got {type(value).__name__}")


I think the type hint is wrong here. It should be str/bytes. since we do json.dumps

Message is not true.

Siddharth Mitra (sidmitra) force-pushed the SM-mypy-v2 branch 2 times, most recently from 646a4e5 to f8dd194 Compare May 13, 2026 20:56

Siddharth Mitra (sidmitra) changed the title ~~chore: enable mypy pre-commit hook at v2.1.0~~ chore: enable mypy v2 pre-commit hook, fix all resulting lint errors May 13, 2026

Siddharth Mitra (sidmitra) requested review from Gautham Goli (GauthamGoli) and Allu Venkata Harshavardhan Reddy (avhvr) May 13, 2026 21:08

Siddharth Mitra (sidmitra) self-assigned this May 13, 2026

Allu Venkata Harshavardhan Reddy (avhvr) approved these changes May 14, 2026

View reviewed changes

Siddharth Mitra (sidmitra) force-pushed the SM-python-313 branch from cdcf0c9 to 69216b6 Compare May 14, 2026 16:35

Siddharth Mitra (sidmitra) force-pushed the SM-mypy-v2 branch from c7ee085 to cb7e548 Compare May 14, 2026 16:35

Base automatically changed from SM-python-313 to main May 14, 2026 16:36

Siddharth Mitra (sidmitra) force-pushed the SM-mypy-v2 branch from cb7e548 to d9a1977 Compare May 14, 2026 16:37

Siddharth Mitra (sidmitra) added 5 commits May 14, 2026 18:43

chore: enable mypy pre-commit hook at v2.1.0

5453dbb

Uncomment and upgrade the mirrors-mypy pre-commit hook from the previously commented-out v0.902 stub to v2.1.0.

fix: wrap long pylint disable comments under 88 chars

5ce1a8f

Move inline disable comments to pylint: disable-next= on preceding line to keep lines within the 88-character flake8 limit.

Copilot AI review requested due to automatic review settings May 14, 2026 22:50

Siddharth Mitra (sidmitra) force-pushed the SM-mypy-v2 branch from d9a1977 to 5ce1a8f Compare May 14, 2026 22:50

Copilot started reviewing on behalf of Siddharth Mitra (sidmitra) May 14, 2026 22:51 View session

Copilot AI reviewed May 14, 2026

View reviewed changes

Siddharth Mitra (sidmitra) added 5 commits May 14, 2026 18:56

Add mypy as dev dependency.

540fa94

Update readme

6d98984

Add mypy, lint fixes

68cd4d8

Update readme

c187088

Siddharth Mitra (sidmitra) changed the title ~~chore: enable mypy v2 pre-commit hook, fix all resulting lint errors~~ chore: enable mypy v2 pre-commit hook; fix all type errors it surfaces May 14, 2026

Siddharth Mitra (sidmitra) added 2 commits May 14, 2026 19:50

refactor: use public before/after_receive_hooks properties in tests

86bd1d4

Fix var name

3b7349d

Siddharth Mitra (sidmitra) added 2 commits May 14, 2026 20:09

Add cast

5691cee

Siddharth Mitra (sidmitra) changed the title ~~chore: enable mypy v2 pre-commit hook; fix all type errors it surfaces~~ chore: enable mypy v2 pre-commit hook; fix all lint/type errors it surfaces May 15, 2026

Siddharth Mitra (sidmitra) commented May 15, 2026

View reviewed changes

Fix producer type

be97f5b

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

chore: enable mypy v2 pre-commit hook; fix all lint/type errors it surfaces#31

chore: enable mypy v2 pre-commit hook; fix all lint/type errors it surfaces#31
Siddharth Mitra (sidmitra) wants to merge 15 commits into
mainfrom
SM-mypy-v2

Siddharth Mitra (sidmitra) commented May 13, 2026 •

edited

Loading

Uh oh!

snyk-io Bot commented May 13, 2026 •

edited

Loading

Uh oh!

Copilot AI left a comment

Uh oh!

Uh oh!

Uh oh!

Siddharth Mitra (sidmitra) May 15, 2026

Uh oh!

Reviewers

Assignees

Labels

Milestone

Development

Uh oh!

3 participants

Conversation

Siddharth Mitra (sidmitra) commented May 13, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary

mypy v2 — config

mypy v2 — source fixes

pylint v4 — fixes

ruff S101 — assert replacements

Uh oh!

snyk-io Bot commented May 13, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

⚠️ Snyk checks are incomplete.

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Uh oh!

Uh oh!

Siddharth Mitra (sidmitra) May 15, 2026

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Milestone

Development

Uh oh!

3 participants

Siddharth Mitra (sidmitra) commented May 13, 2026 •

edited

Loading

snyk-io Bot commented May 13, 2026 •

edited

Loading