ESLint v9.15.0 released

This release updates the @eslint/plugin-kit dependency to the latest version 0.2.3 which includes the fix for security advisory GHSA-7q7g-4xm8-89cq.

Highlights

meta.defaultOptions

Rules can now specify default options. ESLint will recursively merge any user-provided options elements on top of the default elements.

This feature makes it easier to work with options in rules.

// my-rule.js
export default {
    meta: {
        defaultOptions: [{
            alias: "basic",
            ignoreClassFields: false
        }],
        schema: [{
            type: "object",
            properties: {
                alias: {
                    type: "string"
                },
                ignoreClassFields: {
                    type: "boolean"
                }
            },
            additionalProperties: false
        }]
    },
    create(context) {

        // `context.options` is guaranteed to be an array with a single object
        // that has a string property `alias` and a boolean property `ignoreClassFields`.
        // If the rule is enabled with no options specified in the configuration file,
        // `alias` will be `"basic"`, and `ignoreClassFields` will be `false`.
        const [{ alias, ignoreClassFields }] = context.options;

        return { /* ... */ };
    }
};

This feature also allows document generators, other tools and integrations, and end users to easily find the default options for rules.

Other notable changes

• Custom languages can now provide the normalizeLanguageOptions(languageOptions) method. The return value will be used as languageOptions when calling parse(), createSourceCode(), and applyLanguageOptions() methods and as the value of context.languageOptions property in rules.
• The no-useless-computed-key rule now fully supports object destructuring patterns.

Features

• 01557ce feat: Implement Language#normalizeLanguageOptions() (#19104) (Nicholas C. Zakas)
• 2edc0e2 feat: add meta.defaultOptions (#17656) (Josh Goldberg ✨)
• bdec50e feat: fix no-useless-computed-key false negative with __proto__ (#19123) (Milos Djermanovic)
• 3087c9e feat: add meta object to @eslint/js plugin (#19095) (Francesco Trotta)

Bug Fixes

• fd33f13 fix: update types for no-restricted-imports rule (#19060) (Nitin Kumar)
• bd35098 fix: switch away from Node.js node:assert and AssertionError (#19082) (Josh Goldberg ✨)
• 9db5b15 fix: unsafe report for no-lonely-if (#19087) (Abraham Guo)
• 68fa497 fix: ignore files on a different drive on Windows (#19069) (Francesco Trotta)
• 4ce625a fix: upgrade @humanwhocodes/retry@0.4.1 to avoid debug logs (#19102) (Milos Djermanovic)

Documentation

• d927920 docs: fix styles in no-js mode (#18916) (Tanuj Kanti)
• 09bc2a8 docs: Update README (GitHub Actions Bot)
• 39089c8 docs: add no-useless-computed-key examples with object patterns (#19109) (Milos Djermanovic)
• 895c60f docs: add missing messageId property and suggestion properties (#19122) (fnx)
• 298625e docs: Change CLI -c to use flat config (#19103) (Nicholas C. Zakas)
• 522d8a3 docs: add deprecation on indent, quotes and semi rule types (#19090) (Marco Pasqualetti)

Chores

• 2967d91 chore: upgrade @eslint/js@9.15.0 (#19133) (Milos Djermanovic)
• b441bee chore: package.json update for @eslint/js release (Jenkins)
• 7d6bf4a chore: upgrade @eslint/core@0.9.0 (#19131) (Milos Djermanovic)
• 902e707 chore: upgrade @eslint/plugin-kit@0.2.3 (#19130) (Milos Djermanovic)
• 5ff6c1d chore: bump cross-spawn (#19125) (Ian Bobinac)
• cceccc7 chore: update dependency @eslint/json to ^0.6.0 (#19117) (renovate[bot])
• 0da3f73 chore: update algolia referrer (#19114) (Strek)
• 4f08332 ci: unpin trunk-io/trunk-action (#19108) (Francesco Trotta)
• 6b75683 perf: optimize text-table by replacing regex with trimEnd (#19061) (Nitin Kumar)