ESLint v10.12.0: SourceCode tokens/comments types + rule fixes (2 Oct 2026)

On 2 October 2026, ESLint published v10.12.0, a minor release that adds features and fixes bugs from the previous release. ShopperCove did not upgrade a production lint pipeline for this note and did not run benchmarks. Package identity was confirmed on the npm registry on 5 October 2026 (eslint@10.12.0, dist-tag latest). Primary source: the official ESLint v10.12.0 release blog. This is a docs-based upgrade checklist—not performance advice and not a security advisory (no CVEs are claimed here).

There is no affiliate link in this article. This post has no affiliate links.

SourceCode: tokens and comments in types/docs

Rule authors work with ESLint’s SourceCode object. Its getText(), getLoc(), and getRange() methods have long accepted a node, token, or comment at runtime, but documentation did not describe every argument type, and TypeScript definitions rejected some valid calls (for example, passing a comment).

v10.12.0 updates the documentation and type definitions to match actual behavior and to align with the core SourceCodeBase interface used in language plugins:

• Existing call sites that already pass nodes/tokens/comments are unaffected at runtime.
• TypeScript code that implements or mocks SourceCode may need getText / getLoc / getRange signatures updated to accept tokens and comments.

Feature commits called out in the blog: allow SourceCode#getText() to accept tokens and comments (#21340); handle astral letters in new-cap (#21357).

Rule fixes (edge cases, Unicode, autofix)

The blog lists rules updated for edge cases, including autofix behavior and supplementary Unicode / astral letter handling:

• consistent-return
• max-lines-per-function
• new-cap
• no-eval
• no-invalid-this
• no-loss-of-precision
• prefer-arrow-callback
• prefer-exponentiation-operator

Notable fix blurbs from the same release notes:

Area	What the notes say
prefer-arrow-callback	False positive in conditional test fixed
max-lines-per-function	Skip lines with multiple comments
Astral letters	Fixes spanning consistent-return, no-eval, no-invalid-this (and new-cap feat)
prefer-exponentiation-operator	Autofix for async function base
curly	Missing space after else in autofix
id-length	Correct message for long private names
getFunctionHeadLoc	Support TSFunctionType
no-loss-of-precision	False positive with 0.e5

Docs / chores (skim)

Documentation clarifications include one-var separateRequires matching any require() call, and a typo fix in no-unused-expressions. Chores include ecosystem plugin updates, CodeQL action bumps, Prettier dependency bumps, a perf change caching normalized config globals per languageOptions, and removal of CLAUDE.md in favor of AGENTS.md. Treat chores as release hygiene unless your fork tracked those files.

Hands-on upgrade checklist

1. Inventory: npm ls eslint (or check the lockfile). Note whether you are below 10.12.0.
2. Pin / bump in staging: install eslint@10.12.0 (or newer patch on the 10.12 line when available). Confirm with npm view eslint version → expect 10.12.0 as latest as of sources read 5 Oct 2026.
3. TypeScript plugin / custom SourceCode mocks: if you implement SourceCode / SourceCodeBase, update getText / getLoc / getRange typings to accept tokens and comments.
4. Re-run lint + autofix CI: especially suites that enable the rules listed above—watch for changed autofixes on prefer-exponentiation-operator, curly, and fewer false positives on prefer-arrow-callback / no-loss-of-precision.
5. Unicode / identifiers: if you lint code with astral-plane identifiers, re-check new-cap and related rules after the bump.
6. Do not invent security urgency: this minor is typed as features + bugfixes in the official blog; ShopperCove is not attaching CVE IDs.

ShopperCove did not change production ESLint versions for this article. Prefer the official release post over third-party roundups.

Bottom line

ESLint v10.12.0 (2 Oct 2026) is a practical minor: SourceCode docs/types finally match token/comment arguments, plus a batch of rule and autofix fixes (including astral letter handling). Pin eslint@10.12.0 when ready. No affiliate.

Sources

• 01registry.npmjs.org/eslint/10.12.0
• 02npmjs.com/package/eslint
• 03github.com/eslint/eslint

Related

• 01shoppercove.com/blog/vite-plus-1-0-unified-toolchain-october-2026
• 02shoppercove.com/blog/playwright-1-63-test-locks-october-2026
• 03shoppercove.com/blog/astro-7-3-preview-ignore-lock-october-2026
• 04shoppercove.com/blog/angular-router-ssr-queryparams-dos-october-2026
• 05shoppercove.com/blog/nodejs-26-lts-october-2026-schedule-change
• 06shoppercove.com/blog/nextjs-15-lts-end-of-support-october-2026
• 07shoppercove.com/blog/nextjs-16-3-8-security-release-2026
• 08shoppercove.com/blog/firefox-157-security-fixes-css-changes-october-2026