[Henry Su (hsusul)]

Closes #11538.

Summary of Changes

At runtime, typing._AnnotatedAlias.__getattr__ delegates attribute access to __origin__ (the underlying annotated type).

In getTypeOfMemberAccessWithBaseType:

• Preserved baseType.props?.typeForm as baseTypeForm before stripping special forms.
• When member lookup on an Annotated special form produces an error or no member, falls back to evaluating member access against the underlying typeForm.
• Added sample test annotated10.py and test suite entry in typeEvaluator7.test.ts verifying member access on an Annotated alias value.

[Bill Schnurr (bschnurr)]

🔒 Automated review in progress — Bill Schnurr (@bschnurr) is auto-reviewing this PR.

[Bill Schnurr (bschnurr)]

Verification: The relevant tests could not be fully run in the isolated environment; this review is not fully verified.

Result: could-not-verify

Summary: No tests executed because the verification container could not start: no trusted sandbox image is configured for `microsoft/pyright`. The PR adds the targeted `Annotated10` Jest case covering member access through an `Annotated` alias. Verification is therefore blocked by the environment.

Test runs: 2 not run

• ⚠️ Not run | Dependency and test discovery | git status --short && git diff --name-status upstream/main...HEAD && git diff --stat upstream/main...HEAD && if [ -d packages/pyright-internal/node_modules ]; then echo DEPS_PRESENT; else echo DEPS_MISSING; fi && node -e "const p=require('./packages/pyright-internal/package.json'); console.log(JSON.stringify(p.scripts))"
• ⚠️ Not run | Annotated10 | node ./node_modules/jest/bin/jest.js typeEvaluator7.test -t Annotated10 --runInBand

⚠️ Dependency and test discovery diagnostic output

Container verification could not start: no trusted sandbox image is configured for microsoft/pyright.

⚠️ Annotated10 diagnostic output

Not attempted after the verification container failed to start.

[Bill Schnurr (bschnurr)]

Approved via Review Center.

[Heejae Chang (heejaechang)]

Approved via Review Center.

[Heejae Chang (heejaechang)]

🔴 Pyright CLI QA — 348b77a5 — verdict: red

Automated CLI checks compared this change with its base revision.
10 focused check(s) completed.

Needs review: reportAttributeAccessIssue no longer reported

The base reports reportAttributeAccessIssue for this example; the PR does not. Is this change intended?

Reproduction and observed results

Create these files in an empty directory:

main.py

from typing import Annotated, ClassVar, LiteralString, TypeGuard

class C:
    value: ClassVar[int] = 1

# These origins are typing objects, not the classes their annotations describe.
Text = Annotated[LiteralString, "metadata"]
Guard = Annotated[TypeGuard[C], "metadata"]
ClassValue = Annotated[ClassVar[C], "metadata"]

# Each read must be rejected: each raises AttributeError at runtime.
reveal_type(Text.upper)
reveal_type(Guard.bit_length)
reveal_type(ClassValue.value)

pyrightconfig.json

{
  "include": [
    "main.py"
  ],
  "typeCheckingMode": "basic",
  "pythonVersion": "3.13"
}

runtime_check.py

"""Check that typing-special-form origins do not provide class attributes."""
from typing import Annotated, ClassVar, LiteralString, TypeGuard

class C:
    value: ClassVar[int] = 1

for origin, member in (
    (LiteralString, 'upper'),
    (TypeGuard[C], 'bit_length'),
    (ClassVar[C], 'value'),
):
    alias = Annotated[origin, 'metadata']
    try:
        getattr(alias, member)
    except AttributeError:
        print(f'{origin}: {member} raises AttributeError as expected')
    else:
        raise AssertionError(f'{origin} unexpectedly exposes {member}')

From that directory, run each built Pyright revision:

node <pyright-cli-entrypoint> --outputjson -p .

Base 7464296a7cec3ff1db73222f2598bfb51e6d7b23

{
  "exit_code": 1,
  "diagnostics": [
    {
      "file": "main.py",
      "severity": "error",
      "rule": "reportAttributeAccessIssue",
      "message": "Cannot access attribute \"bit_length\" for class \"Annotated\"\n  Attribute \"bit_length\" is unknown",
      "range": {
        "start": [
          12,
          18
        ],
        "end": [
          12,
          28
        ]
      }
    },
    {
      "file": "main.py",
      "severity": "error",
      "rule": "reportAttributeAccessIssue",
      "message": "Cannot access attribute \"upper\" for class \"Annotated\"\n  Attribute \"upper\" is unknown",
      "range": {
        "start": [
          11,
          17
        ],
        "end": [
          11,
          22
        ]
      }
    },
    {
      "file": "main.py",
      "severity": "error",
      "rule": "reportAttributeAccessIssue",
      "message": "Cannot access attribute \"value\" for class \"Annotated\"\n  Attribute \"value\" is unknown",
      "range": {
        "start": [
          13,
          23
        ],
        "end": [
          13,
          28
        ]
      }
    },
    {
      "file": "main.py",
      "severity": "information",
      "rule": null,
      "message": "Type of \"ClassValue.value\" is \"Unknown\"",
      "range": {
        "start": [
          13,
          12
        ],
        "end": [
          13,
          28
        ]
      }
    },
    {
      "file": "main.py",
      "severity": "information",
      "rule": null,
      "message": "Type of \"Guard.bit_length\" is \"Unknown\"",
      "range": {
        "start": [
          12,
          12
        ],
        "end": [
          12,
          28
        ]
      }
    },
    {
      "file": "main.py",
      "severity": "information",
      "rule": null,
      "message": "Type of \"Text.upper\" is \"Unknown\"",
      "range": {
        "start": [
          11,
          12
        ],
        "end": [
          11,
          22
        ]
      }
    }
  ]
}

PR 348b77a5c0f54d199341d5ac80980f99b9d53e68

{
  "exit_code": 0,
  "diagnostics": [
    {
      "file": "main.py",
      "severity": "information",
      "rule": null,
      "message": "Type of \"ClassValue.value\" is \"int\"",
      "range": {
        "start": [
          13,
          12
        ],
        "end": [
          13,
          28
        ]
      }
    },
    {
      "file": "main.py",
      "severity": "information",
      "rule": null,
      "message": "Type of \"Guard.bit_length\" is \"(self: TypeGuard[C]) -> int\"",
      "range": {
        "start": [
          12,
          12
        ],
        "end": [
          12,
          28
        ]
      }
    },
    {
      "file": "main.py",
      "severity": "information",
      "rule": null,
      "message": "Type of \"Text.upper\" is \"Overload[(self: LiteralString) -> LiteralString, (self: LiteralString) -> str]\"",
      "range": {
        "start": [
          11,
          12
        ],
        "end": [
          11,
          22
        ]
      }
    }
  ]
}

Diagnostic ranges use zero-based line and character positions.

[Henry Su (hsusul)]

Not intended. All five QA examples were regressions, fixed in f7c9b2f. The fallback now runs only for reads of non-dunder names on an implicit alias whose Annotated origin is a plain class. These cases are no longer delegated:

• forward-reference, Literal, TypeAliasType, and PEP 695 origins
• PEP 695 aliases of Annotated
• dunder names
• del
• variables that only hold an alias (the IntAlias if flag else TextAlias case)

Assignment reports a single error again. annotated11.py covers each QA example and fails without the fix. annotated10.py still passes. typeEvaluator and checker suites: 1292 passed.