Add noImplicitReexport Config Option by GregMFriedman · Pull Request #11290 · microsoft/pyright

GregMFriedman · 2026-02-20T16:34:34Z

Summary

Adds a noImplicitReexport boolean config option (default: true) that mirrors mypy's no_implicit_reexport flag. When set to false, plain from X import Y imports in py.typed packages are treated as valid re-exports for public names (no leading underscore), suppressing false-positive reportPrivateImportUsage errors. Names with a leading underscore remain private regardless of this setting.

Closes #11288

Motivation

Projects that use both mypy and Pyright encounter false positives when a py.typed library re-exports symbols via plain imports without __all__ or the redundant-alias form. mypy's default (no_implicit_reexport = false) accepts these as valid re-exports; Pyright previously had no equivalent escape hatch.

Changes

diagnosticRules.ts: add noImplicitReexport enum value
configOptions.ts: add to DiagnosticRuleSet, getBooleanDiagnosticRules(), and all four preset defaults
pyrightconfig.schema.json: add definition and property references
typeEvaluator.ts: guard both reportPrivateImportUsage raise sites to skip public names when noImplicitReexport=false
docs/configuration.md: document the new option and add comparison table row
import.pytyped.noImplicitReexport.fourslash.ts: fourslash test verifying public names pass and _-prefixed names still error
privateImportUsage.test.ts: unit tests for both noImplicitReexport=false and =true behavior

Introduces a new boolean diagnostic rule `noImplicitReexport` (default: true) that mirrors mypy's `no_implicit_reexport` flag. No behavior change yet — this commit adds the enum value, DiagnosticRuleSet field, preset defaults, and JSON schema definition/references.

GregMFriedman · 2026-02-20T16:49:09Z

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packages/pyright-internal/src/analyzer/typeEvaluator.ts

rchiodo · 2026-02-20T17:14:29Z

packages/vscode-pyright/schemas/pyrightconfig.schema.json

      "title": "Treat typing-specific aliases to standard types as deprecated",
      "default": false
    },
+    "noImplicitReexport": {


I think you need a setting for this in the vscode-pyright package.json. Like the example here:

pyright/packages/vscode-pyright/package.json

Line 194 in c971180

"reportGeneralTypeIssues": {

added in 1e6d878

Shouldn't the title be the same for both?

yes, sorry--fixed now (and i've simplified the failing tests b/c I couldn't figure out why the strings weren't matching, they looked exactly the same)

Adds two unit tests to the noImplicitReexport describe block: - A test.failing() asserting that public names should not produce reportPrivateImportUsage errors when noImplicitReexport=false - A passing test confirming the default (noImplicitReexport=true) still errors on both public and private implicit imports The test.failing() will be un-failed in the next commit when the behavior is implemented in typeEvaluator.ts.

When noImplicitReexport=false, reportPrivateImportUsage is suppressed for public names (no leading underscore) that are implicitly re-exported via plain `from X import Y` in py.typed packages, mirroring mypy's no_implicit_reexport=false behavior. Names with a leading underscore continue to be reported regardless of this setting. Changes: - typeEvaluator.ts: guard both reportPrivateImportUsage raise sites - privateImportUsage.test.ts: promote test.failing() -> test() - docs/configuration.md: document noImplicitReexport with table row - import.pytyped.noImplicitReexport.fourslash.ts: fourslash test covering public names (no error) and underscore-prefixed names (still errors) Closes microsoft#11288

rchiodo · 2026-02-20T18:26:05Z

packages/vscode-pyright/package.json

+                "python.analysis.noImplicitReexport": {
+                    "type": "boolean",
+                    "default": true,
+                    "description": "Require explicit re-export of imported symbols in py.typed packages (mirrors mypy's no_implicit_reexport)",


Sorry I still find this confusing. Might this be better?

"When true, imported symbols in py.typed packages require explicit re-export (via all or 'as' alias). Set to false to allow plain imports as re-exports for public names."

done, i agree that is better

github-actions · 2026-02-20T18:31:12Z

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

sympy (https://github.com/sympy/sympy)
-   .../projects/sympy/sympy/solvers/ode/lie_group.py:618:61 - error: Operator "-" not supported for type "Basic | Unknown" (reportOperatorIssue)
-   .../projects/sympy/sympy/solvers/ode/nonhomogeneous.py:467:28 - error: Argument of type "Unknown | None" cannot be assigned to parameter "expr" of type "Expr" in function "make_args"
+   .../projects/sympy/sympy/solvers/ode/nonhomogeneous.py:467:28 - error: Argument of type "Expr | Unknown | None" cannot be assigned to parameter "expr" of type "Expr" in function "make_args"
-     Type "Unknown | None" is not assignable to type "Expr"
+     Type "Expr | Unknown | None" is not assignable to type "Expr"
+     Attribute "pop" is unknown (reportAttributeAccessIssue)
+   .../projects/sympy/sympy/solvers/ode/ode.py:609:22 - error: Cannot access attribute "pop" for class "tuple[()]"
+     Attribute "pop" is unknown (reportAttributeAccessIssue)
+   .../projects/sympy/sympy/solvers/ode/ode.py:609:22 - error: Cannot access attribute "pop" for class "tuple[str, ...]"
+   .../projects/sympy/sympy/solvers/ode/ode.py:1515:38 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:1516:38 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:1526:9 - error: No overloads for "update" match the provided arguments (reportCallIssue)
+   .../projects/sympy/sympy/solvers/ode/ode.py:1526:12 - error: "update" is not a known attribute of "None" (reportOptionalMemberAccess)
+   .../projects/sympy/sympy/solvers/ode/ode.py:1526:19 - error: Argument of type "Unknown | dict[Unknown, Unknown] | None" cannot be assigned to parameter "m" of type "Iterable[tuple[str, Unknown]]" in function "update"
+     Type "Unknown | dict[Unknown, Unknown] | None" is not assignable to type "Iterable[tuple[str, Unknown]]"
+       "None" is incompatible with protocol "Iterable[tuple[str, Unknown]]"
+         "__iter__" is not present (reportArgumentType)
+   .../projects/sympy/sympy/solvers/ode/ode.py:1533:43 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:1533:64 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:1539:9 - error: No overloads for "update" match the provided arguments (reportCallIssue)
+   .../projects/sympy/sympy/solvers/ode/ode.py:1539:12 - error: "update" is not a known attribute of "None" (reportOptionalMemberAccess)
+   .../projects/sympy/sympy/solvers/ode/ode.py:1539:19 - error: Argument of type "Unknown | dict[Unknown, Unknown] | None" cannot be assigned to parameter "m" of type "Iterable[tuple[str, Unknown]]" in function "update"
+     Type "Unknown | dict[Unknown, Unknown] | None" is not assignable to type "Iterable[tuple[str, Unknown]]"
+       "None" is incompatible with protocol "Iterable[tuple[str, Unknown]]"
+         "__iter__" is not present (reportArgumentType)
+   .../projects/sympy/sympy/solvers/ode/ode.py:1546:43 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:1546:74 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:1552:9 - error: No overloads for "update" match the provided arguments (reportCallIssue)
+   .../projects/sympy/sympy/solvers/ode/ode.py:1552:12 - error: "update" is not a known attribute of "None" (reportOptionalMemberAccess)
+   .../projects/sympy/sympy/solvers/ode/ode.py:1552:19 - error: Argument of type "Unknown | dict[Unknown, Unknown] | None" cannot be assigned to parameter "m" of type "Iterable[tuple[str, Unknown]]" in function "update"
+     Type "Unknown | dict[Unknown, Unknown] | None" is not assignable to type "Iterable[tuple[str, Unknown]]"
+       "None" is incompatible with protocol "Iterable[tuple[str, Unknown]]"
+         "__iter__" is not present (reportArgumentType)
+   .../projects/sympy/sympy/solvers/ode/ode.py:1559:49 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:1559:70 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
-   .../projects/sympy/sympy/solvers/ode/ode.py:1689:36 - error: Cannot access attribute "lhs" for class "Expr"
-     Attribute "lhs" is unknown (reportAttributeAccessIssue)
-   .../projects/sympy/sympy/solvers/ode/ode.py:1689:55 - error: Cannot access attribute "rhs" for class "Expr"
-     Attribute "rhs" is unknown (reportAttributeAccessIssue)
-   .../projects/sympy/sympy/solvers/ode/ode.py:1690:36 - error: Cannot access attribute "lhs" for class "Expr"
-     Attribute "lhs" is unknown (reportAttributeAccessIssue)
-   .../projects/sympy/sympy/solvers/ode/ode.py:1691:17 - error: No overloads for "__setitem__" match the provided arguments (reportCallIssue)
-   .../projects/sympy/sympy/solvers/ode/ode.py:1691:17 - error: Argument of type "Equality | BooleanFalse | BooleanTrue | Unknown | Expr" cannot be assigned to parameter "value" of type "Equality | BooleanFalse | BooleanTrue" in function "__setitem__"
-     Type "Equality | BooleanFalse | BooleanTrue | Unknown | Expr" is not assignable to type "Equality | BooleanFalse | BooleanTrue"
-       Type "Expr" is not assignable to type "Equality | BooleanFalse | BooleanTrue"
-         "Expr" is not assignable to "Equality"
-         "Expr" is not assignable to "BooleanFalse"
-         "Expr" is not assignable to "BooleanTrue" (reportArgumentType)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3378:7 - error: "update" is not a known attribute of "None" (reportOptionalMemberAccess)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3378:38 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3379:7 - error: "update" is not a known attribute of "None" (reportOptionalMemberAccess)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3379:38 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3380:14 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3381:14 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3382:14 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3394:50 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3395:50 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3396:50 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3436:5 - error: No overloads for "update" match the provided arguments (reportCallIssue)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3436:7 - error: "update" is not a known attribute of "None" (reportOptionalMemberAccess)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3436:14 - error: Argument of type "Unknown | dict[Unknown, Unknown] | None" cannot be assigned to parameter "m" of type "Iterable[tuple[str, Unknown]]" in function "update"
+     Type "Unknown | dict[Unknown, Unknown] | None" is not assignable to type "Iterable[tuple[str, Unknown]]"
+       "None" is incompatible with protocol "Iterable[tuple[str, Unknown]]"
+         "__iter__" is not present (reportArgumentType)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3437:18 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3437:43 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3438:9 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3438:16 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3438:24 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3438:31 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3439:9 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3439:15 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3439:23 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3439:30 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3440:7 - error: "update" is not a known attribute of "None" (reportOptionalMemberAccess)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3440:46 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3440:54 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3441:9 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3441:19 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)
+   .../projects/sympy/sympy/solvers/ode/ode.py:3441:29 - error: Object of type "None" is not subscriptable (reportOptionalSubscript)

... (truncated 275 lines) ...

Addresses review feedback requesting a VS Code setting entry for the new noImplicitReexport config option.

rchiodo · 2026-02-20T18:39:19Z

Sorry I'm going to defer to Eric's judgement on the issue. Unless you can convince him otherwise, I don't think we'll accept this PR.

GregMFriedman marked this pull request as ready for review February 20, 2026 16:40

rchiodo reviewed Feb 20, 2026

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GregMFriedman force-pushed the feat/no-implicit-reexport branch from 2d79d6e to fe8aac0 Compare February 20, 2026 17:26

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GregMFriedman force-pushed the feat/no-implicit-reexport branch from fe8aac0 to da7c318 Compare February 20, 2026 17:27

GregMFriedman force-pushed the feat/no-implicit-reexport branch from da7c318 to 1e6d878 Compare February 20, 2026 17:39

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GregMFriedman force-pushed the feat/no-implicit-reexport branch from 1e6d878 to 391c541 Compare February 20, 2026 18:17

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Add python.analysis.noImplicitReexport to vscode-pyright package.json

bb1dd82

Addresses review feedback requesting a VS Code setting entry for the new noImplicitReexport config option.

GregMFriedman force-pushed the feat/no-implicit-reexport branch from 391c541 to bb1dd82 Compare February 20, 2026 18:33

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Add noImplicitReexport Config Option#11290

Add noImplicitReexport Config Option#11290
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