require-meta-schema.md

Require rules to implement a meta.schema property (eslint-plugin/require-meta-schema)

💼 This rule is enabled in the ✅ recommended config.

💡 This rule is manually fixable by editor suggestions.

Defining a schema for each rule allows eslint to validate that configuration options are passed correctly. Even when there are no options for a rule, a schema can still be defined as an empty array to validate that no data is mistakenly passed to the rule.

As of ESLint v9, ESLint will validate that options are not provided to a rule when a schema is omitted.

Rule Details

This rule requires ESLint rules to have a valid meta.schema property.

Examples of incorrect code for this rule:

/* eslint eslint-plugin/require-meta-schema: error */

module.exports = {
  meta: {},
  create(context) {
    /* ... */
  },
};

module.exports = {
  meta: { schema: null },
  create(context) {
    /* ... */
  },
};

module.exports = {
  meta: { schema: [] },
  create(context) {
    const options = context.options; /* using options when schema is empty */
  },
};

Examples of correct code for this rule:

/* eslint eslint-plugin/require-meta-schema: error */

module.exports = {
  meta: { schema: [] }, // ensures no options are passed to the rule
  create(context) {
    /* ... */
  },
};

module.exports = {
  meta: {
    schema: [
      {
        type: 'object',
        properties: {
          exceptRange: {
            type: 'boolean',
          },
        },
        additionalProperties: false,
      },
    ],
  },
  create(context) {
    /* ... */
  },
};

Options

Name	Description	Type	Default
requireSchemaPropertyWhenOptionless	Whether the rule should require the meta.schema property to be specified (with schema: []) for rules that have no options.	Boolean	true

When Not To Use It

As mentioned in the introduction, the need for this rule is reduced as of ESLint v9.

Further Reading

• working-with-rules#options-schemas