/** * @fileoverview require default case in switch statements * @author Aliaksei Shytkin */ "use strict"; const DEFAULT_COMMENT_PATTERN = /^no default$/iu; //------------------------------------------------------------------------------ // Rule Definition //------------------------------------------------------------------------------ /** @type {import('../types').Rule.RuleModule} */ module.exports = { meta: { type: "suggestion", defaultOptions: [{}], docs: { description: "Require `default` cases in `switch` statements", recommended: false, url: "https://eslint.org/docs/latest/rules/default-case", }, schema: [ { type: "object", properties: { commentPattern: { type: "string", }, }, additionalProperties: false, }, ], messages: { missingDefaultCase: "Expected a default case.", }, }, create(context) { const [options] = context.options; const commentPattern = options.commentPattern ? new RegExp(options.commentPattern, "u") : DEFAULT_COMMENT_PATTERN; const sourceCode = context.sourceCode; //-------------------------------------------------------------------------- // Helpers //-------------------------------------------------------------------------- /** * Shortcut to get last element of array * @param {*[]} collection Array * @returns {any} Last element */ function last(collection) { return collection.at(-1); } //-------------------------------------------------------------------------- // Public //-------------------------------------------------------------------------- return { SwitchStatement(node) { if (!node.cases.length) { /* * skip check of empty switch because there is no easy way * to extract comments inside it now */ return; } const hasDefault = node.cases.some(v => v.test === null); if (!hasDefault) { let comment; const lastCase = last(node.cases); const comments = sourceCode.getCommentsAfter(lastCase); if (comments.length) { comment = last(comments); } if ( !comment || !commentPattern.test(comment.value.trim()) ) { context.report({ node, messageId: "missingDefaultCase", }); } } }, }; }, };