fix Variable type is not narrowed after "if" containing both call to "Never-returning" function and "raise" #5186

[asukaminato0721]

Summary

Fixes #5186

Flow merging now preserves the Never call’s termination information, so the example narrows x to str.

• I am a human, and I fully understand the code I am submitting.

Test Plan

add test

[meta-codesync]

This pull request has been imported. If you are a Meta employee, you can view this in D124568673. (Because this pull request was imported automatically, there will not be any future comments.)

[github-actions]

Diff from mypy_primer, showing the effect of this PR on open source code:

============================================================
SUMMARY
============================================================
Total: +64 new errors, -62 fixed errors
By preset: +6/-34 (default), +30/-35 (strict)

Projects with changes (32):
  pip: +6 -1
  cloud-init: +1 -10
  egglog-python: +0 -1
  rotki: +4 -0
  bokeh: +0 -1
  pytest: +0 -1
  jax: +4 -2
  twine: +0 -1
  aiortc: +2 -0
  scikit-learn: +2 -5
  freqtrade: +0 -1
  pwndbg: +11 -2
  setuptools: +1 -1
  apprise: +2 -0
  mongo-python-driver: +4 -3
  schemathesis: +4 -4
  beartype: +1 -1
  stone: +10 -2
  pandera: +0 -1
  hydpy: +0 -1
  pandas: +0 -1
  dd-trace-py: +1 -0
  mypy: +0 -1
  meson: +3 -6
  ecosystem-analyzer: +1 -0
  core: +3 -8
  paasta: +0 -1
  jinja: +0 -1
  sphinx: +2 -1
  xarray: +0 -2
  spack: +0 -1
  scrapy: +2 -2
============================================================

FULL DIFF DETAILS
------------------------------------------------------------

pip (https://github.com/pypa/pip)
- ERROR src/pip/_internal/resolution/resolvelib/resolver.py:302:16-22: Implicit conversion of `set[str]` to `bool` is not allowed [implicit-bool]
+ ERROR src/pip/_internal/resolution/resolvelib/resolver.py:302:16-22: Implicit conversion of `set[Unknown]` to `bool` is not allowed [implicit-bool]
+ ERROR src/pip/_internal/resolution/resolvelib/resolver.py:307:13-17: The type of `leaf` is unknown; it is inferred as an implicit `Any` [unknown-variable-type]
+ ERROR src/pip/_internal/resolution/resolvelib/resolver.py:308:16-20: The type of this argument is unknown [unknown-argument-type]
+ ERROR src/pip/_internal/resolution/resolvelib/resolver.py:310:21-25: The type of this argument is unknown [unknown-argument-type]
+ ERROR src/pip/_internal/resolution/resolvelib/resolver.py:312:13-17: The type of `leaf` is unknown; it is inferred as an implicit `Any` [unknown-variable-type]
+ ERROR src/pip/_internal/resolution/resolvelib/resolver.py:313:26-30: The type of this argument is unknown [unknown-argument-type]

cloud-init (https://github.com/canonical/cloud-init)
- ERROR cloudinit/config/cc_apt_configure.py:399:13-17: The type of `line` is unknown; it is inferred as an implicit `Any` [unknown-variable-type]
- ERROR cloudinit/config/cc_apt_configure.py:399:28-38: The type of attribute `splitlines` is unknown; it is inferred as an implicit `Any` [unknown-attribute-access]
- ERROR cloudinit/config/cc_apt_configure.py:400:21-31: The type of attribute `startswith` is unknown; it is inferred as an implicit `Any` [unknown-attribute-access]
- ERROR cloudinit/config/cc_apt_configure.py:407:20-32: The type of `cols` is unknown; it is inferred as an implicit `Any` [unknown-variable-type]
- ERROR cloudinit/config/cc_apt_configure.py:407:25-30: The type of attribute `split` is unknown; it is inferred as an implicit `Any` [unknown-attribute-access]
- ERROR cloudinit/config/cc_apt_configure.py:408:20-24: The type of this argument is unknown [unknown-argument-type]
- ERROR cloudinit/config/cc_apt_configure.py:410:28-38: The type of attribute `startswith` is unknown; it is inferred as an implicit `Any` [unknown-attribute-access]
- ERROR cloudinit/config/cc_apt_configure.py:411:25-28: The type of `col` is unknown; it is inferred as an implicit `Any` [unknown-variable-type]
- ERROR cloudinit/config/cc_apt_configure.py:413:32-40: The type of attribute `endswith` is unknown; it is inferred as an implicit `Any` [unknown-attribute-access]
- ERROR cloudinit/config/cc_apt_configure.py:417:28-71: The type of `line` is unknown; it is inferred as an implicit `Any` [unknown-variable-type]
+ ERROR cloudinit/config/cc_disk_setup.py:378:20-22: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]

egglog-python (https://github.com/egraphs-good/egglog-python)
- ERROR python/egglog/egraph.py:2817:24-35: Argument `BaseExpr | Fact` is not assignable to parameter `expr` with type `BaseExpr` in function `expr_action` [bad-argument-type]

rotki (https://github.com/rotki/rotki)
+ ERROR rotkehlchen/chain/evm/decoding/balancer/v3/decoder.py:174:24-26: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]
+ ERROR rotkehlchen/exchanges/bitstamp.py:304:29-31: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]
+ ERROR rotkehlchen/exchanges/bitstamp.py:324:13-16: The type of `idx` is unknown; it is inferred as an implicit `Any` [unknown-variable-type]
+ ERROR rotkehlchen/exchanges/bitstamp.py:325:40-43: The type of this argument is unknown [unknown-argument-type]

bokeh (https://github.com/bokeh/bokeh)
- ERROR src/bokeh/command/bootstrap.py:120:8-11: `ret` may be uninitialized [unbound-name]

pytest (https://github.com/pytest-dev/pytest)
- ERROR src/_pytest/doctest.py:585:33-39: `module` may be uninitialized [unbound-name]

jax (https://github.com/google/jax)
+ ERROR jax/_src/array.py:1251:10-12: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]
- ERROR jax/_src/lax/control_flow/loops.py:657:44-50: The type of this argument is unknown [unknown-argument-type]
- ERROR jax/_src/pallas/triton/lowering.py:2625:49-50: The type of this argument is unknown [unknown-argument-type]
+ ERROR jax/_src/pjit.py:1912:3-36: Unused `# pyrefly: ignore` comment for code(s): unbound-name [unused-ignore]
+ ERROR jax/experimental/mosaic/gpu/profiler.py:280:14-16: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]
+ ERROR jax/experimental/mosaic/gpu/profiler.py:340:43-53: The return type of this lambda is unknown; it is inferred as an implicit `Any` [unknown-return-type]

twine (https://github.com/pypa/twine)
- ERROR twine/repository.py:161:16-20: `resp` may be uninitialized [unbound-name]

aiortc (https://github.com/aiortc/aiortc)
+ ERROR src/aiortc/rtcpeerconnection.py:86:14-16: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]
+ ERROR src/aiortc/rtp.py:534:18-20: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]

scikit-learn (https://github.com/scikit-learn/scikit-learn)
- ERROR sklearn/utils/_pprint.py:267:24-29: String literal used as condition. It's equivalent to `False` [redundant-condition]
- ERROR sklearn/utils/_pprint.py:267:24-29: Implicit conversion of `Literal['']` to `bool` is not allowed [implicit-bool]
+ ERROR sklearn/utils/_pprint.py:267:24-29: Implicit conversion of `Literal['', ', '] | Unknown` to `bool` is not allowed [implicit-bool]
- ERROR sklearn/utils/_pprint.py:318:24-29: String literal used as condition. It's equivalent to `False` [redundant-condition]
- ERROR sklearn/utils/_pprint.py:318:24-29: Implicit conversion of `Literal['']` to `bool` is not allowed [implicit-bool]
+ ERROR sklearn/utils/_pprint.py:318:24-29: Implicit conversion of `Literal['', ', '] | Unknown` to `bool` is not allowed [implicit-bool]
- ERROR sklearn/utils/multiclass.py:422:17-33: `first_row_or_val` may be uninitialized [unbound-name]

freqtrade (https://github.com/freqtrade/freqtrade)
- ERROR freqtrade/exchange/exchange.py:3926:31-40: `max_stake` may be uninitialized [unbound-name]

pwndbg (https://github.com/pwndbg/pwndbg)
- ERROR pwndbg/aglib/kernel/kallsyms.py:129:45-48: `pos` may be uninitialized [unbound-name]
+ ERROR pwndbg/aglib/kernel/kallsyms.py:114:22-24: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]
+ ERROR pwndbg/aglib/kernel/kallsyms.py:115:28-30: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]
+ ERROR pwndbg/aglib/kernel/kallsyms.py:139:20-33: The type of `position` is unknown; it is inferred as an implicit `Any` [unknown-variable-type]
+ ERROR pwndbg/aglib/kernel/kallsyms.py:149:39-47: The type of this argument is unknown [unknown-argument-type]
+ ERROR pwndbg/aglib/kernel/kallsyms.py:149:76-84: The type of this argument is unknown [unknown-argument-type]
+ ERROR pwndbg/aglib/kernel/kallsyms.py:159:16-24: Returning implicit Any from function declared to return "int" [no-any-return-implicit]
+ ERROR pwndbg/aglib/kernel/kmod.py:219:14-16: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]
+ ERROR pwndbg/aglib/kernel/ktask.py:694:60-79: `+` is not supported between `int` and `None` [unsupported-operation]
+ ERROR pwndbg/aglib/kernel/ktask.py:695:58-76: `+` is not supported between `int` and `None` [unsupported-operation]
+ ERROR pwndbg/aglib/kernel/ktask.py:721:12-33: Returned type `tuple[str, int | None]` is not assignable to declared return type `tuple[str, int]` [bad-return]
- ERROR pwndbg/aglib/kernel/ktask.py:940:11-17: Implicit conversion of `Value` to `bool` is not allowed [implicit-bool]
+ ERROR pwndbg/aglib/kernel/ktask.py:940:11-17: Implicit conversion of `Value | None` to `bool` is not allowed [implicit-bool]

setuptools (https://github.com/pypa/setuptools)
- ERROR setuptools/_distutils/dist.py:530:15-19: Implicit conversion of `Sequence[str] | tuple[Sequence[str], OptionDummy | Unknown]` to `bool` is not allowed [implicit-bool]
+ ERROR setuptools/_distutils/dist.py:530:15-19: Implicit conversion of `Sequence[str] | tuple[Sequence[str], OptionDummy | Unknown] | Unknown` to `bool` is not allowed [implicit-bool]

apprise (https://github.com/caronc/apprise)
+ ERROR apprise/conversion/commonmark.py:1678:20-22: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]
+ ERROR apprise/conversion/commonmark.py:1688:17-45: The type of `bound` is unknown; it is inferred as an implicit `Any` [unknown-variable-type]

mongo-python-driver (https://github.com/mongodb/mongo-python-driver)
- ERROR pymongo/asynchronous/_kms_connect.py:87:19-39: Expected a callable, got `None` [not-callable]
- ERROR pymongo/synchronous/_kms_connect.py:87:19-39: Expected a callable, got `None` [not-callable]
+ ERROR tools/ensure_future_annotations_import.py:23:11-13: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]
- ERROR tools/ensure_future_annotations_import.py:37:4-11: Implicit conversion of `list[Path]` to `bool` is not allowed [implicit-bool]
+ ERROR tools/ensure_future_annotations_import.py:37:4-11: Implicit conversion of `list[Unknown]` to `bool` is not allowed [implicit-bool]
+ ERROR tools/ensure_future_annotations_import.py:39:9-13: The type of `item` is unknown; it is inferred as an implicit `Any` [unknown-variable-type]
+ ERROR tools/ensure_future_annotations_import.py:40:15-19: The type of this argument is unknown [unknown-argument-type]

schemathesis (https://github.com/schemathesis/schemathesis)
- ERROR src/schemathesis/specs/openapi/coverage/_schema.py:2555:32-40: Implicit conversion of `None` to `bool` is not allowed [implicit-bool]
+ ERROR src/schemathesis/specs/openapi/coverage/_schema.py:2555:32-40: Implicit conversion of `Any | None` to `bool` is not allowed [implicit-bool]
- ERROR src/schemathesis/specs/openapi/coverage/_schema.py:2569:36-44: Implicit conversion of `None` to `bool` is not allowed [implicit-bool]
+ ERROR src/schemathesis/specs/openapi/coverage/_schema.py:2569:36-44: Implicit conversion of `Any | None` to `bool` is not allowed [implicit-bool]
- ERROR src/schemathesis/specs/openapi/coverage/_schema.py:2585:36-44: Implicit conversion of `None` to `bool` is not allowed [implicit-bool]
+ ERROR src/schemathesis/specs/openapi/coverage/_schema.py:2585:36-44: Implicit conversion of `Any | None` to `bool` is not allowed [implicit-bool]
- ERROR src/schemathesis/specs/openapi/coverage/_schema.py:2606:32-40: Implicit conversion of `None` to `bool` is not allowed [implicit-bool]
+ ERROR src/schemathesis/specs/openapi/coverage/_schema.py:2606:32-40: Implicit conversion of `Any | None` to `bool` is not allowed [implicit-bool]

beartype (https://github.com/beartype/beartype)
- ERROR beartype/_check/make/checkmakecls.py:262:20-32: `func_checker` may be uninitialized [unbound-name]
+ ERROR beartype/door/_cls/pep/doorpep484604.py:114:27-29: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]

stone (https://github.com/dropbox/stone)
+ ERROR stone/_vendor/ply/yacc.py:2344:20-22: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]
+ ERROR stone/_vendor/ply/yacc.py:2345:23-25: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]
+ ERROR stone/_vendor/ply/yacc.py:2354:21-23: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]
+ ERROR stone/_vendor/ply/yacc.py:2355:24-26: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]
- ERROR stone/_vendor/ply/yacc.py:2405:38-40: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]
+ ERROR stone/_vendor/ply/yacc.py:2403:17-18: The type of `i` is unknown; it is inferred as an implicit `Any` [unknown-variable-type]
+ ERROR stone/_vendor/ply/yacc.py:2404:20-21: The type of this argument is unknown [unknown-argument-type]
+ ERROR stone/_vendor/ply/yacc.py:2405:33-34: The type of this argument is unknown [unknown-argument-type]
+ ERROR stone/_vendor/ply/yacc.py:2406:29-30: The type of this argument is unknown [unknown-argument-type]
+ ERROR stone/_vendor/ply/yacc.py:2406:32-38: The type of attribute `append` is unknown; it is inferred as an implicit `Any` [unknown-attribute-access]
- ERROR stone/compiler.py:125:28-48: Implicit conversion of `Unknown | None` to `bool` is not allowed [implicit-bool]
+ ERROR stone/compiler.py:125:28-48: Implicit conversion of `None` to `bool` is not allowed [implicit-bool]

pandera (https://github.com/pandera-dev/pandera)
- ERROR tests/pyspark/test_pyspark_container.py:657:32-39: `read_df` may be uninitialized [unbound-name]

hydpy (https://github.com/hydpy-dev/hydpy)
- ERROR hydpy/core/filetools.py:608:16-26: Returned type `str | None` is not assignable to declared return type `str` [bad-return]

pandas (https://github.com/pandas-dev/pandas)
- ERROR pandas/io/json/_json.py:1713:44-50: `record` may be uninitialized [unbound-name]

dd-trace-py (https://github.com/DataDog/dd-trace-py)
+ ERROR ddtrace/aiguard/integrations/strands.py:136:13-15: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]

mypy (https://github.com/python/mypy)
- ERROR mypy/semanal.py:8221:17-8229:18: This code is unreachable [unreachable]

meson (https://github.com/mesonbuild/meson)
+ ERROR mesonbuild/dependencies/pkgconfig.py:466:25-27: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]
+ ERROR mesonbuild/dependencies/pkgconfig.py:468:21-23: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]
- ERROR mesonbuild/dependencies/pkgconfig.py:555:12-25: Implicit conversion of `list[str]` to `bool` is not allowed [implicit-bool]
+ ERROR mesonbuild/dependencies/pkgconfig.py:555:12-25: Implicit conversion of `list[Unknown]` to `bool` is not allowed [implicit-bool]
- ERROR mesonbuild/modules/cmake.py:288:72-73: `p` may be uninitialized [unbound-name]
- ERROR mesonbuild/modules/cmake.py:288:94-100: `stdout` may be uninitialized [unbound-name]
- ERROR mesonbuild/modules/cmake.py:288:110-116: `stderr` may be uninitialized [unbound-name]
- ERROR mesonbuild/modules/codegen.py:355:39-42: `bin` may be uninitialized [unbound-name]
- ERROR mesonbuild/modules/codegen.py:417:40-43: `bin` may be uninitialized [unbound-name]

ecosystem-analyzer (https://github.com/astral-sh/ecosystem-analyzer)
+ ERROR src/ecosystem_analyzer/diagnostic.py:107:26-28: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]

core (https://github.com/home-assistant/core)
+ ERROR homeassistant/components/aws_s3/__init__.py:69:16-22: `client` may be uninitialized [unbound-name]
+ ERROR homeassistant/components/cloudflare_r2/__init__.py:72:26-32: `client` may be uninitialized [unbound-name]
+ ERROR homeassistant/components/google_assistant/data_redaction.py:29:14-16: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]
- ERROR homeassistant/components/google_assistant/data_redaction.py:36:31-54: Argument `str` is not assignable to parameter `object` with type `Never` in function `list.append` [bad-argument-type]
- ERROR homeassistant/components/google_assistant/data_redaction.py:39:27-30: Argument `str` is not assignable to parameter `object` with type `Never` in function `list.append` [bad-argument-type]
- ERROR homeassistant/components/google_assistant/data_redaction.py:40:12-18: Returned type `list[Never]` is not assignable to declared return type `list[str]` [bad-return]
- ERROR homeassistant/components/notion/coordinator.py:162:29-36: `bridges` may be uninitialized [unbound-name]
- ERROR homeassistant/components/notion/coordinator.py:163:31-40: `listeners` may be uninitialized [unbound-name]
- ERROR homeassistant/components/notion/coordinator.py:164:29-36: `sensors` may be uninitialized [unbound-name]
- ERROR homeassistant/components/notion/coordinator.py:165:38-54: `user_preferences` may be uninitialized [unbound-name]
- ERROR homeassistant/util/loop.py:105:19-36: `integration_frame` may be uninitialized [unbound-name]

paasta (https://github.com/yelp/paasta)
- ERROR paasta_tools/cli/utils.py:442:33-39: `output` may be uninitialized [unbound-name]

jinja (https://github.com/pallets/jinja)
- ERROR src/jinja2/filters.py:730:34-38: `unit` may be uninitialized [unbound-name]

sphinx (https://github.com/sphinx-doc/sphinx)
+ ERROR sphinx/ext/coverage.py:308:21-23: Cannot infer type of empty container; it will be treated as containing `Any` [implicit-any-empty-container]
- ERROR sphinx/util/docstrings.py:28:16-48: Implicit conversion of `Literal[True] | None` to `bool` is not allowed [implicit-bool]
+ ERROR sphinx/util/docstrings.py:28:16-48: Implicit conversion of `bool | None` to `bool` is not allowed [implicit-bool]

xarray (https://github.com/pydata/xarray)
- ERROR xarray/plot/dataarray_plot.py:333:12-20: `plotfunc` may be uninitialized [unbound-name]
- ERROR xarray/structure/combine.py:261:13-25: The type of this argument is unknown [unknown-argument-type]

spack (https://github.com/spack/spack)
- ERROR lib/spack/spack/config.py:1089:23-31: `existing` may be uninitialized [unbound-name]

scrapy (https://github.com/scrapy/scrapy)
- ERROR docs/utils/linkfix.py:53:24-33: Implicit conversion of `None` to `bool` is not allowed [implicit-bool]
+ ERROR docs/utils/linkfix.py:53:24-33: Implicit conversion of `str | Any | None` to `bool` is not allowed [implicit-bool]
- ERROR docs/utils/linkfix.py:54:52-61: Argument `None` is not assignable to parameter `data` with type `str` in function `pathlib.Path.write_text` [bad-argument-type]
+ ERROR docs/utils/linkfix.py:54:52-61: Argument `Unknown | None` is not assignable to parameter `data` with type `str` in function `pathlib.Path.write_text` [bad-argument-type]