fix(eslint-plugin): honor ignored base types on generic classes #11767

OleksandraKordonets · 2025-11-19T00:37:27Z

PR Checklist

Addresses an existing open issue: fixes Bug: [no-base-in-string] generic classes don't check for ignored superclasses #11758
That issue was marked as accepting prs
Steps in Contributing were taken

Overview

This PR fixes a false positive in @typescript-eslint/no-base-to-string where .toString() calls on values typed as generic subclasses of ignored types, such as Error, were being incorrectly reported. The rule previously only checked the type’s direct name, causing cases like class Boom<T> extends Error {} to be treated as unsafe, so this update adds recursive base-type checking with cycle protection to ensure that if a type or any of its ancestors match ignoredTypeNames, the call is allowed. A test is included to confirm .toString() is not reported for both direct and chained generic subclasses of Error, while preserving all existing rule behavior and configuration.

typescript-eslint · 2025-11-19T00:37:30Z

Thanks for the PR, @OleksandraKordonets!

typescript-eslint is a 100% community driven project, and we are incredibly grateful that you are contributing to that community.

The core maintainers work on this in their personal time, so please understand that it may not be possible for them to review your work immediately.

Thanks again!

🙏 Please, if you or your company is finding typescript-eslint valuable, help us sustain the project by sponsoring it transparently on https://opencollective.com/typescript-eslint.

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nx-cloud · 2025-11-19T00:38:52Z

View your CI Pipeline Execution ↗ for commit 52a4d74

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codecov · 2025-11-19T00:51:14Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.49%. Comparing base (d26e9de) to head (52a4d74).
⚠️ Report is 8 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #11767   +/-   ##
=======================================
  Coverage   90.49%   90.49%           
=======================================
  Files         522      522           
  Lines       53357    53362    +5     
  Branches     8909     8914    +5     
=======================================
+ Hits        48284    48289    +5     
  Misses       5057     5057           
  Partials       16       16

Flag	Coverage Δ
unittest	`90.49% <100.00%> (+<0.01%)`	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...kages/eslint-plugin/src/rules/no-base-to-string.ts	`99.07% <100.00%> (+0.01%)`	⬆️

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

JoshuaKGoldberg

LGTM, thanks! ✨

I just left a couple of stylistic nitpicks in case you're interested. No worries at all if you prefer the code as-is, I just like refactoring as a form of reading the code. Totally up to you. 🙂

packages/eslint-plugin/src/rules/no-base-to-string.ts

JoshuaKGoldberg · 2025-11-24T14:08:45Z

packages/eslint-plugin/src/rules/no-base-to-string.ts

+      if (ignoredTypeNames.includes(typeName)) {
+        return true;
+      }
+
+      return getBaseTypesForType(type).some(base =>
+        isIgnoredTypeOrBase(base, seen),
      );


[Style] If you want to save a few lines 😄

Suggested change

if (ignoredTypeNames.includes(typeName)) {

return true;

}

return getBaseTypesForType(type).some(base =>

isIgnoredTypeOrBase(base, seen),

);

return (

ignoredTypeNames.includes(getTypeName(checker, type)) ||

getBaseTypesForType(type).some(base => isIgnoredTypeOrBase(base, seen))

);

JoshuaKGoldberg · 2025-11-24T14:11:33Z

That issue was marked as accepting prs

Btw, I wouldn't recommend sending PRs for issues that aren't yet marked as accepting prs. In this case it worked out because the issue was straightforward and accepted. But we've previously had to close PRs where the author put in a lot of work but the issue wasn't actually something that could be accepted. That feels bad for everyone.

https://typescript-eslint.io/docs/contributing

JoshuaKGoldberg

Thanks! 🙌

@Higangssh

| datasource | package | from | to | | ---------- | -------------------------------- | ------ | ------ | | npm | @typescript-eslint/eslint-plugin | 8.48.0 | 8.48.1 | | npm | @typescript-eslint/parser | 8.48.0 | 8.48.1 | ## [v8.48.1](https://github.com/typescript-eslint/typescript-eslint/blob/HEAD/packages/eslint-plugin/CHANGELOG.md#8481-2025-12-02) ##### 🩹 Fixes - **eslint-plugin:** \[restrict-template-expressions] check base types in allow list ([#11764](typescript-eslint/typescript-eslint#11764), [#11759](typescript-eslint/typescript-eslint#11759)) - **eslint-plugin:** honor ignored base types on generic classes ([#11767](typescript-eslint/typescript-eslint#11767)) - **eslint-plugin:** \[consistent-type-exports] check value flag before resolving alias ([#11769](typescript-eslint/typescript-eslint#11769)) ##### ❤️ Thank You - Josh Goldberg - OleksandraKordonets - SangheeSon [@Higangssh](https://github.com/Higangssh) - tao You can read about our [versioning strategy](https://typescript-eslint.io/users/versioning) and [releases](https://typescript-eslint.io/users/releases) on our website.

@Higangssh

| datasource | package | from | to | | ---------- | -------------------------------- | ------ | ------ | | npm | @typescript-eslint/eslint-plugin | 8.48.0 | 8.48.1 | | npm | @typescript-eslint/parser | 8.48.0 | 8.48.1 | ## [v8.48.1](https://github.com/typescript-eslint/typescript-eslint/blob/HEAD/packages/eslint-plugin/CHANGELOG.md#8481-2025-12-02) ##### 🩹 Fixes - **eslint-plugin:** \[restrict-template-expressions] check base types in allow list ([#11764](typescript-eslint/typescript-eslint#11764), [#11759](typescript-eslint/typescript-eslint#11759)) - **eslint-plugin:** honor ignored base types on generic classes ([#11767](typescript-eslint/typescript-eslint#11767)) - **eslint-plugin:** \[consistent-type-exports] check value flag before resolving alias ([#11769](typescript-eslint/typescript-eslint#11769)) ##### ❤️ Thank You - Josh Goldberg - OleksandraKordonets - SangheeSon [@Higangssh](https://github.com/Higangssh) - tao You can read about our [versioning strategy](https://typescript-eslint.io/users/versioning) and [releases](https://typescript-eslint.io/users/releases) on our website.

This PR contains the following updates: | Package | Change | Age | Confidence | |---|---|---|---| | [@typescript-eslint/eslint-plugin](https://typescript-eslint.io/packages/eslint-plugin) ([source](https://github.com/typescript-eslint/typescript-eslint/tree/HEAD/packages/eslint-plugin)) | [`8.47.0` -> `8.48.1`](https://renovatebot.com/diffs/npm/@typescript-eslint%2feslint-plugin/8.47.0/8.48.1) | [![age](https://developer.mend.io/api/mc/badges/age/npm/@typescript-eslint%2feslint-plugin/8.48.1?slim=true)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://developer.mend.io/api/mc/badges/confidence/npm/@typescript-eslint%2feslint-plugin/8.47.0/8.48.1?slim=true)](https://docs.renovatebot.com/merge-confidence/) | | [@typescript-eslint/parser](https://typescript-eslint.io/packages/parser) ([source](https://github.com/typescript-eslint/typescript-eslint/tree/HEAD/packages/parser)) | [`8.47.0` -> `8.48.1`](https://renovatebot.com/diffs/npm/@typescript-eslint%2fparser/8.47.0/8.48.1) | [![age](https://developer.mend.io/api/mc/badges/age/npm/@typescript-eslint%2fparser/8.48.1?slim=true)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://developer.mend.io/api/mc/badges/confidence/npm/@typescript-eslint%2fparser/8.47.0/8.48.1?slim=true)](https://docs.renovatebot.com/merge-confidence/) | --- ### Release Notes <details> <summary>typescript-eslint/typescript-eslint (@typescript-eslint/eslint-plugin)</summary> ### [`v8.48.1`](https://github.com/typescript-eslint/typescript-eslint/blob/HEAD/packages/eslint-plugin/CHANGELOG.md#8481-2025-12-02) [Compare Source](typescript-eslint/typescript-eslint@v8.48.0...v8.48.1) ##### 🩹 Fixes - **eslint-plugin:** \[restrict-template-expressions] check base types in allow list ([#11764](typescript-eslint/typescript-eslint#11764), [#11759](typescript-eslint/typescript-eslint#11759)) - **eslint-plugin:** honor ignored base types on generic classes ([#11767](typescript-eslint/typescript-eslint#11767)) - **eslint-plugin:** \[consistent-type-exports] check value flag before resolving alias ([#11769](typescript-eslint/typescript-eslint#11769)) ##### ❤️ Thank You - Josh Goldberg - OleksandraKordonets - SangheeSon [@Higangssh](https://github.com/Higangssh) - tao You can read about our [versioning strategy](https://typescript-eslint.io/users/versioning) and [releases](https://typescript-eslint.io/users/releases) on our website. ### [`v8.48.0`](https://github.com/typescript-eslint/typescript-eslint/blob/HEAD/packages/eslint-plugin/CHANGELOG.md#8480-2025-11-24) [Compare Source](typescript-eslint/typescript-eslint@v8.47.0...v8.48.0) ##### 🚀 Features - **eslint-plugin:** \[no-redundant-type-constituents] use assignability checking for redundancy checks ([#10744](typescript-eslint/typescript-eslint#10744)) ##### 🩹 Fixes - **typescript-estree:** disallow binding patterns in parameter properties ([#11760](typescript-eslint/typescript-eslint#11760)) - **eslint-plugin:** \[consistent-generic-constructors] ignore when constructor is typed array ([#10477](typescript-eslint/typescript-eslint#10477)) ##### ❤️ Thank You - Dima Barabash [@dbarabashh](https://github.com/dbarabashh) - JamesHenry [@JamesHenry](https://github.com/JamesHenry) - Josh Goldberg - mdm317 [@gen-ip-1](https://github.com/gen-ip-1) You can read about our [versioning strategy](https://typescript-eslint.io/users/versioning) and [releases](https://typescript-eslint.io/users/releases) on our website. </details> <details> <summary>typescript-eslint/typescript-eslint (@typescript-eslint/parser)</summary> ### [`v8.48.1`](https://github.com/typescript-eslint/typescript-eslint/blob/HEAD/packages/parser/CHANGELOG.md#8481-2025-12-02) [Compare Source](typescript-eslint/typescript-eslint@v8.48.0...v8.48.1) This was a version bump only for parser to align it with other projects, there were no code changes. You can read about our [versioning strategy](https://typescript-eslint.io/users/versioning) and [releases](https://typescript-eslint.io/users/releases) on our website. ### [`v8.48.0`](https://github.com/typescript-eslint/typescript-eslint/blob/HEAD/packages/parser/CHANGELOG.md#8480-2025-11-24) [Compare Source](typescript-eslint/typescript-eslint@v8.47.0...v8.48.0) This was a version bump only for parser to align it with other projects, there were no code changes. You can read about our [versioning strategy](https://typescript-eslint.io/users/versioning) and [releases](https://typescript-eslint.io/users/releases) on our website. </details> --- ### Configuration 📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about these updates again. --- - [ ] If you want to rebase/retry this PR, check this box --- This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).  Reviewed-on: https://git.csmpro.ru/csmpro/mapban/pulls/57 Co-authored-by: Renovate Bot <renovate@csmpro.ru> Co-committed-by: Renovate Bot <renovate@csmpro.ru>

@Higangssh

| datasource | package | from | to | | ---------- | -------------------------------- | ------ | ------ | | npm | @typescript-eslint/eslint-plugin | 8.48.0 | 8.48.1 | | npm | @typescript-eslint/parser | 8.48.0 | 8.48.1 | ## [v8.48.1](https://github.com/typescript-eslint/typescript-eslint/blob/HEAD/packages/eslint-plugin/CHANGELOG.md#8481-2025-12-02) ##### 🩹 Fixes - **eslint-plugin:** \[restrict-template-expressions] check base types in allow list ([#11764](typescript-eslint/typescript-eslint#11764), [#11759](typescript-eslint/typescript-eslint#11759)) - **eslint-plugin:** honor ignored base types on generic classes ([#11767](typescript-eslint/typescript-eslint#11767)) - **eslint-plugin:** \[consistent-type-exports] check value flag before resolving alias ([#11769](typescript-eslint/typescript-eslint#11769)) ##### ❤️ Thank You - Josh Goldberg - OleksandraKordonets - SangheeSon [@Higangssh](https://github.com/Higangssh) - tao You can read about our [versioning strategy](https://typescript-eslint.io/users/versioning) and [releases](https://typescript-eslint.io/users/releases) on our website.

@Higangssh

| datasource | package | from | to | | ---------- | -------------------------------- | ------ | ------ | | npm | @typescript-eslint/eslint-plugin | 8.48.0 | 8.48.1 | | npm | @typescript-eslint/parser | 8.48.0 | 8.48.1 | ## [v8.48.1](https://github.com/typescript-eslint/typescript-eslint/blob/HEAD/packages/eslint-plugin/CHANGELOG.md#8481-2025-12-02) ##### 🩹 Fixes - **eslint-plugin:** \[restrict-template-expressions] check base types in allow list ([#11764](typescript-eslint/typescript-eslint#11764), [#11759](typescript-eslint/typescript-eslint#11759)) - **eslint-plugin:** honor ignored base types on generic classes ([#11767](typescript-eslint/typescript-eslint#11767)) - **eslint-plugin:** \[consistent-type-exports] check value flag before resolving alias ([#11769](typescript-eslint/typescript-eslint#11769)) ##### ❤️ Thank You - Josh Goldberg - OleksandraKordonets - SangheeSon [@Higangssh](https://github.com/Higangssh) - tao You can read about our [versioning strategy](https://typescript-eslint.io/users/versioning) and [releases](https://typescript-eslint.io/users/releases) on our website.

@Higangssh

| datasource | package | from | to | | ---------- | -------------------------------- | ------ | ------ | | npm | @typescript-eslint/eslint-plugin | 8.48.0 | 8.48.1 | | npm | @typescript-eslint/parser | 8.48.0 | 8.48.1 | ## [v8.48.1](https://github.com/typescript-eslint/typescript-eslint/blob/HEAD/packages/eslint-plugin/CHANGELOG.md#8481-2025-12-02) ##### 🩹 Fixes - **eslint-plugin:** \[restrict-template-expressions] check base types in allow list ([#11764](typescript-eslint/typescript-eslint#11764), [#11759](typescript-eslint/typescript-eslint#11759)) - **eslint-plugin:** honor ignored base types on generic classes ([#11767](typescript-eslint/typescript-eslint#11767)) - **eslint-plugin:** \[consistent-type-exports] check value flag before resolving alias ([#11769](typescript-eslint/typescript-eslint#11769)) ##### ❤️ Thank You - Josh Goldberg - OleksandraKordonets - SangheeSon [@Higangssh](https://github.com/Higangssh) - tao You can read about our [versioning strategy](https://typescript-eslint.io/users/versioning) and [releases](https://typescript-eslint.io/users/releases) on our website.

fix(eslint-plugin): honor ignored base types on generic classes

bef61e2

Merge branch 'main' into issue11758

3d0cf2a

JoshuaKGoldberg previously approved these changes Nov 24, 2025

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JoshuaKGoldberg added the 1 approval >=1 team member has approved this PR; we're now leaving it open for more reviews before we merge label Nov 24, 2025

Address feedback: apply review style suggestions

52a4d74

OleksandraKordonets dismissed JoshuaKGoldberg’s stale review via 52a4d74 November 25, 2025 04:11

JoshuaKGoldberg approved these changes Nov 28, 2025

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JoshuaKGoldberg merged commit 0db02ac into typescript-eslint:main Nov 28, 2025
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chrisbbreuer mentioned this pull request Dec 2, 2025

chore(deps): update all non-major dependencies stacksjs/eslint-plugin#67

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fix(eslint-plugin): honor ignored base types on generic classes #11767

fix(eslint-plugin): honor ignored base types on generic classes #11767

OleksandraKordonets commented Nov 19, 2025 •

edited by JoshuaKGoldberg

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fix(eslint-plugin): honor ignored base types on generic classes #11767

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OleksandraKordonets commented Nov 19, 2025 •

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