Add more typing to debugpy and switch to 'standard' type checking mode by rchiodo · Pull Request #1637 · microsoft/debugpy

Rich Chiodo (rchiodo) · 2024-07-24T21:34:39Z

This PR adds type annotations across debugpy and switches Pyright to standard type-checking mode (typeCheckingMode = "standard"), with # type: ignore comments disabled repository-wide (enableTypeIgnoreComments = false). It was originally used to exercise Pylance, but the stricter typing is a worthwhile improvement on its own.

The vast majority of the diff is pure type annotations. However, a handful of non-annotation changes were needed (or surfaced by the stricter checking) and are called out below so reviewers do not have to infer them from the diff.

Non-annotation (behavioral) changes

adapter/clients.py – launch/attach handling now preserves request_options; out-of-order configurationDone requests fail explicitly; and an evaluate request that cannot be propagated to the debug server now receives a failure response instead of hanging.
adapter/launchers.py – for a debug launch, spawn_debuggee now asserts servers.listener is not None before reading the address/token, restoring fail-fast behavior (and narrowing the Optional) instead of silently skipping connection info.
common/messaging.py
- Message.__call__ no longer uses assert for control flow: it explicitly raises when the payload is an Exception, so behavior is identical under python -O.
- Request.respond(None) now models a successful empty response as an empty MessageDict (instead of None), matching how incoming empty responses are already parsed, so Response.body is always a MessageDict or an Exception.
- OutgoingRequest disables the inherited _parse/_handle via explicit class-level attributes.
common/singleton.py – ThreadSafeSingleton.assert_locked is no longer a @staticmethod and uses a side-effect-free lock._is_owned() check instead of acquire(blocking=False)/release(), avoiding an RLock recursion-count leak (and an unbalanced release() under python -O).
common/json.py – _converter narrows accepted numeric types from numbers.Number to int/float only (DAP number payloads are int/float; Decimal/complex/Fraction never appear).
common/util.py – Observable.observers keeps an immutable () class default (typed Sequence) and the += call sites were switched to reassignment, avoiding mutation of a shared class attribute.
server/api.py – an empty adapter-endpoints read now raises the intended EOFError instead of falling through to json.loads and surfacing JSONDecodeError.

Focused regression tests were added for the behavioral changes (see tests/debugpy/common/test_messaging.py, tests/debugpy/common/test_singleton.py, tests/debugpy/common/test_json.py, and tests/debugpy/server/test_api.py).

Suppression policy

Because enableTypeIgnoreComments = false, # type: ignore has no effect and must not be used. Where a diagnostic must be suppressed (correct code the checker cannot verify, e.g. access to a private-but-stable runtime API), a narrow # pyright: ignore[reportSpecificRule] is used instead. This convention is now documented in CONTRIBUTING.md.

…bugpy into rchiodo/type_standard

…odo/type_standard # Conflicts: # CONTRIBUTING.md # src/debugpy/adapter/clients.py # src/debugpy/adapter/launchers.py # src/debugpy/adapter/servers.py # src/debugpy/common/sockets.py # src/debugpy/server/api.py # src/debugpy/server/cli.py # tests/requirements.txt

Heejae Chang (heejaechang) · 2026-07-16T19:01:35Z

🔒 Automated review in progress — Heejae Chang (@heejaechang) is auto-reviewing this PR.

Heejae Chang (heejaechang)

Approved via Review Center.

pytest-retry re-runs flaky tests' setup/call phases directly without firing pytest_runtest_makereport, so pytest 9's tmp_path finalizer never repopulates its tmppath_result_key stash entry after the first attempt's teardown deletes it, raising KeyError at teardown (seen on py314 when test_attach_pid_client was retried). Re-seed the stash key in a pytest_runtest_setup hook, which pytest-retry runs on each retry. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Stella Huang (StellaHuang95) · 2026-08-06T19:01:11Z

🔒 Automated review in progress — Stella Huang (@StellaHuang95) is auto-reviewing this PR.

Stella Huang (StellaHuang95)

Approved via Review Center.

Address review feedback: cover the owned-vs-unlocked invariant that assert_locked now enforces (_is_owned() check). Verifies attribute access succeeds when the current thread owns the lock and fails fast (AssertionError) on read/write when unlocked. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Stella Huang (StellaHuang95)

Approved via Review Center.

# Conflicts: # src/debugpy/common/log.py

Stella Huang (StellaHuang95)

Approved via Review Center.

- messaging.py: replace setattr-based _parse/_handle override on OutgoingRequest with explicit class-level typed optional attributes so the override stays statically visible to Pyright. - test_messaging.py: pin the respond(None) contract (Response.body is an empty MessageDict, never None), matching incoming empty responses. - test_json.py: add focused regression coverage pinning _converter to int/float and rejecting Decimal/complex/Fraction. - CONTRIBUTING.md: document the standard Pyright mode and the repository-wide prohibition on '# type: ignore' (use targeted '# pyright: ignore[...]'). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Stella Huang (StellaHuang95)

Approved via Review Center.

Restores tests/debugpy/server/test_api.py (referenced by the PR description) with focused coverage for the empty-read -> EOFError path in debugpy.server.api.listen(): an empty read (b'') from the adapter endpoints socket must surface an EOFError rather than falling through to json.loads. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Mark the class-local decorator helper static so Pyright no longer treats its wrapped callable as an instance-method self parameter. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Stella Huang (StellaHuang95)

Approved via Review Center.

Rich Chiodo (rchiodo) added 8 commits July 5, 2024 18:15

Make typing even more restrictive and start fixing some more errors

3d7808e

More typing

e528e2d

Finish typing debupy python code

622e3c6

Rest of the API typed

50e8d1d

Put back wait_for_client variable

063bb6a

Update test requirements

5dd7fe9

Fix converter

3ee1940

Merge remote-tracking branch 'upstream/main' into rchiodo/type_standard

891d5df

Rich Chiodo (rchiodo) requested a review from a team as a code owner July 24, 2024 21:34

Fix linter

931d83c

Erik De Bonte (debonte) reviewed Jul 24, 2024

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Comment thread src/debugpy/adapter/clients.py Outdated

Comment thread src/debugpy/adapter/clients.py Outdated

Comment thread src/debugpy/common/messaging.py Outdated

Comment thread src/debugpy/common/messaging.py Outdated

Rich Chiodo (rchiodo) added 3 commits July 24, 2024 22:01

Fix messaging error

7a1350a

Review feedback and fixup more types

8ce6670

fix request_options

4d609d2

Erik De Bonte (debonte) previously approved these changes Jul 24, 2024

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Rich Chiodo (rchiodo) added 11 commits July 24, 2024 17:34

Fix debug output and put wait back the way it was

fddf0de

Skip importing sessions unless type checking

c02affd

Hide types to prevent runtime issue

bfd9b88

Fix linter

046fe6f

Remove inappropriate static method

0196522

Merge branch 'rchiodo/type_standard' of https://github.com/rchiodo/de…

fac2692

…bugpy into rchiodo/type_standard

Fix linux failures

6e3bde7

Fix type errors

8b8467a

Cannot reference socket even in types

2ce0c69

Merge branch 'rchiodo/type_standard' of https://github.com/rchiodo/de…

e5f1889

…bugpy into rchiodo/type_standard

Fix linter again

9c7c06b

Rich Chiodo (rchiodo) dismissed Erik De Bonte (debonte)’s stale review via 9c7c06b March 31, 2025 23:27

Rich Chiodo (rchiodo) requested a review from a team as a code owner July 16, 2026 19:00

Heejae Chang (heejaechang) approved these changes Jul 21, 2026

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Stella Huang (StellaHuang95) reviewed Aug 6, 2026

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Comment thread src/debugpy/common/singleton.py

Stella Huang (StellaHuang95) approved these changes Aug 6, 2026

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Stella Huang (StellaHuang95) added the review-auto:approved Automated review: no blocking findings (approval posted). label Aug 6, 2026

Stella Huang (StellaHuang95) approved these changes Aug 6, 2026

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Merge remote-tracking branch 'upstream/main' into rchiodo/type_standard

b572d52

# Conflicts: # src/debugpy/common/log.py