2025-04-19 23:12:19 -04:00

102 lines
2.5 KiB
JavaScript

/**
* @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',
});
}
}
},
};
},
};