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/**
* @fileoverview require default case in switch statements
* @author Aliaksei Shytkin
*/
"use strict";
const DEFAULT_COMMENT_PATTERN = /^no default$/iu;
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
/** @type {import('../shared/types').Rule} */
module.exports = {
meta: {
type: "suggestion",
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[0] || {};
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[collection.length - 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" });
}
}
}
};
}
};