prefer-message-ids.md

Require using messageId instead of message to report rule violations (prefer-message-ids)

When reporting a rule violation, it's preferred to provide the violation message with the messageId property instead of the message property. Message IDs provide the following benefits:

• Rule violation messages can be stored in a central meta.messages object for convenient management
• Rule violation messages do not need to be repeated in both the rule file and rule test file

Rule Details

This rule catches usages of the message property when reporting a rule violation.

Examples of incorrect code for this rule:

/* eslint eslint-plugin/prefer-message-ids: error */

module.exports = {
  create (context) {
    return {
      CallExpression (node) {
        context.report({
          node,
          message: 'Some error message.',
        });
      },
    };
  },
};

Examples of correct code for this rule:

/* eslint eslint-plugin/prefer-message-ids: error */

module.exports = {
  meta: {
    messages: {
      someMessageId: 'Some error message',
    },
  },
  create (context) {
    return {
      CallExpression (node) {
        context.report({
          node,
          messageId: 'someMessageId',
        });
      },
    };
  },
};

Further Reading

• messageIds API