build: upgrade typescript-eslint to v8 by aresnik11 · Pull Request #3417 · Codecademy/gamut

aresnik11 · 2026-08-19T15:12:44Z

Overview

Upgrades typescript-eslint from v5 to v8 so the current TypeScript version (5.9.3) is officially supported and yarn lint no longer prints the "TypeScript version not officially supported by @typescript-eslint" warning.

Root cause: @typescript-eslint@5.62 supports TS <5.2, but the repo is on TS 5.9.3. Moving to v8 (via @codecademy/eslint-config 8.0.0 → 8.2.0, which already uses @typescript-eslint@^8.31) resolves it. Pinned to 8.43.0 exact to match mono. No ESLint or Node upgrade needed — v8 peers eslint ^8.57 (repo is on 8.57.1) and Node >=18.18 (repo is on 22).

Commits

Commit	What
Bump typescript-eslint to v8	`@typescript-eslint/*` 5.62 → 8.43.0 (plugin, parser, utils, + new `rule-tester`), `@codecademy/eslint-config` → 8.2.0. Added `eslint-plugin-import` / `-jest` / `-unused-imports` at the root so the shared config's plugins resolve (they no longer hoist under the newer config).
Migrate eslint-plugin-gamut to typescript-eslint v8	`RuleTester` moved to `@typescript-eslint/rule-tester` with flat-config `languageOptions`; `nodenext` resolution in `tsconfig.spec.json`; removed `docs.recommended` from rule meta; `AST_NODE_TYPES` comparisons; removed a duplicate test case.
Adjust eslint rules for typescript-eslint v8	Rule-config changes in `.eslintrc.js` (see below).
Fix v8 lint violations across the repo	Real fixes: jsx-key, unused imports, union dedupe, optional chaining, and the MDX parser crashes.

Rule-config decisions

Bumping the config pulled newer plugin versions, surfacing 139 new lint errors. Handled as:

Disabled (matching mono + the config's existing ban-types / no-empty-interface intent):
- @typescript-eslint/no-empty-object-type (98 hits — mono disables this too)
- @typescript-eslint/no-wrapper-object-types (5)
- @typescript-eslint/no-base-to-string (5 — flags long-standing ReactNode → string aria/id coercions; hardening those is a separate a11y effort, noted in a code comment)
eqeqeq: the 2 hits were idiomatic == null / != null nullish checks → allowed via eqeqeq: ['error', 'always', { null: 'ignore' }] (still enforces === everywhere else).
*.mdx: turned off import/namespace and @typescript-eslint/no-unused-expressions, which misfire on MDX imports and inline prose expressions like {'>'}.
Fixed as real bugs: 7 react/jsx-key, 3 no-unsafe-enum-comparison, 2 no-unused-vars, plus autofixed dedupe / import-sort / optional-chaining.

`eslint-mdx` note

The config bump also moves eslint-mdx 1.x → 3.x. The v3 parser crashed on two docs files (assert.ok(code[lastAttrOffset] === attrQuote)) — caused by multi-line JSX string attributes (<Callout text="line one\n line two" />). Fixed by collapsing those to single-line attributes. No functional change to the docs.

PR Checklist

Related to designs:
Related to JIRA ticket: GMT-1605
Version plan added/updated (or not needed)
I have run this code to verify it works
This PR includes unit tests for the code change
This PR includes testing instructions tests for the code change
The alpha package of this PR is passing end-to-end tests in all relevant Codecademy repositories

Testing Instructions

# From the gamut repo root
yarn install

# 1. The core check: lint runs clean with NO TypeScript-version warning
yarn lint
# Expect: exits 0, and no "WARNING: You are currently running a version of
# TypeScript which is not officially supported" banner.

# 2. eslint-plugin-gamut's own rule tests pass under the v8 RuleTester API
yarn nx test eslint-plugin-gamut
yarn nx build eslint-plugin-gamut

# 3. Confirm the resolved versions are pinned to 8.43.0 (matching mono)
node -e "console.log(require('@typescript-eslint/parser/package.json').version)"   # 8.43.0
node -e "console.log(require('@typescript-eslint/utils/package.json').version)"    # 8.43.0

Expected: yarn lint exits 0 with no version warning; eslint-plugin-gamut tests (45) and build pass; typescript-eslint resolves to 8.43.0.

PR Links and Envs

Repository	PR Link
Monolith	Monolith PR
Mono	Mono PR

typescript-eslint 5.62 -> 8.43.0 (plugin/parser/utils, + rule-tester) and @codecademy/eslint-config 8.0.0 -> 8.2.0, so TS 5.9 is officially supported and the version warning on `yarn lint` goes away. Pinned to 8.43.0 to match mono. Also add import/jest/unused-imports at the root so the shared config's plugins resolve (they no longer hoist under the newer config). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

- RuleTester moved to @typescript-eslint/rule-tester with flat-config languageOptions (v8 dropped ESLintUtils.RuleTester and the string parser) - Use nodenext resolution in tsconfig.spec.json so the rule-tester exports subpaths resolve (still emits CommonJS for ts-jest) - Drop docs.recommended from rule meta (removed from RuleMetaDataDocs in v8) - Compare node types against AST_NODE_TYPES to satisfy no-unsafe-enum-comparison - Remove a duplicate valid test case (v8 RuleTester now rejects duplicates) Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

- Disable no-empty-object-type / no-wrapper-object-types (v8 successors of ban-types / no-empty-interface, which the shared config already disables; mono disables no-empty-object-type too) - Disable no-base-to-string: flags long-standing ReactNode->string aria/id coercions; hardening those is a separate a11y effort - Allow `== null` / `!= null` via eqeqeq { null: 'ignore' } - For *.mdx, turn off import/namespace and no-unused-expressions, which misfire on MDX imports and inline prose expressions Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

nx-cloud · 2026-08-19T15:14:28Z

View your CI Pipeline Execution ↗ for commit bd9abf7

☁️ Nx Cloud last updated this comment at 2026-08-19 15:35:44 UTC

codecov · 2026-08-19T15:17:25Z

⚠️ JUnit XML file not found

The CLI was unable to find any JUnit XML files to upload.
For more help, visit our troubleshooting guide.

- Add missing React keys in styleguide list/story maps (jsx-key) - Preserve the full ButtonTypes union and disable no-duplicate-type-constituents there: the five button components are structurally identical, but the union intentionally enumerates them all - Drop a genuinely redundant `| undefined` on an optional param and a duplicate literal union member (autofix); prefer optional chaining - Disable import/namespace on a dynamic namespace key access it can't statically validate - Collapse multi-line JSX string attributes in two MDX files that crashed the eslint-mdx v3 parser - Import-sort fixes Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

aresnik11 · 2026-08-19T15:26:38Z

      | 'search'
      | 'month'
      | 'tel'
-      | 'time'


duplicate, also listed above on line 336

aresnik11 · 2026-08-19T15:27:31Z

    `import defaultImport from 'fileName.json'`,
    `import defaultImport from 'fileName.md'`,
    `import defaultImport from 'fileName.mdx'`,
-    `import defaultImport from 'fileName.svg'`,


duplicate. same thing on line 19

codecademydev · 2026-08-19T15:37:04Z

📬 Published Alpha Packages:

Package	Version	npm	Diff
`@codecademy/gamut`	`72.5.4-alpha.3f7af6.0`	npm	diff
`@codecademy/gamut-icons`	`9.57.12-alpha.3f7af6.0`	npm	diff
`@codecademy/gamut-illustrations`	`0.58.17-alpha.3f7af6.0`	npm	diff
`@codecademy/gamut-kit`	`3.0.17-alpha.3f7af6.0`	npm	diff
`@codecademy/gamut-patterns`	`0.10.36-alpha.3f7af6.0`	npm	diff
`@codecademy/gamut-styles`	`20.1.1-alpha.3f7af6.0`	npm	diff
`@codecademy/gamut-tests`	`6.0.7-alpha.3f7af6.0`	npm	diff
`@codecademy/variance`	`0.26.2-alpha.3f7af6.0`	npm	diff
`eslint-plugin-gamut`	`2.4.4-alpha.3f7af6.0`	npm	diff

github-actions · 2026-08-19T15:38:46Z

🚀 Styleguide deploy preview ready!

Preview URL: https://6a85ce00e3468583f5c983bc--gamut-preview.netlify.app
Deploy Logs: https://app.netlify.com/projects/gamut-preview/deploys/6a85ce00e3468583f5c983bc

dreamwasp

lgt, would just like to test eslint-plugin-gamut in mono to make sure it still works there

aresnik11 and others added 3 commits August 19, 2026 11:04

aresnik11 force-pushed the ajr-bump-typescript-eslint branch from bd9abf7 to cb87024 Compare August 19, 2026 15:25

aresnik11 commented Aug 19, 2026

View reviewed changes

add version plan

36fd0e3

aresnik11 changed the title ~~Ajr bump typescript eslint~~ build: upgrade typescript-eslint to v8 Aug 19, 2026

aresnik11 marked this pull request as ready for review August 19, 2026 18:39

aresnik11 requested a review from a team as a code owner August 19, 2026 18:39

aresnik11 requested review from LinKCoding and dreamwasp August 19, 2026 18:47

dreamwasp reviewed Aug 19, 2026

View reviewed changes

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build: upgrade typescript-eslint to v8 - #3417

build: upgrade typescript-eslint to v8#3417
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Overview

Commits

Rule-config decisions

eslint-mdx note

PR Checklist

Testing Instructions

PR Links and Envs

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