/**
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* @fileoverview require default case in switch statements
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* @author Aliaksei Shytkin
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*/
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"use strict";
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const DEFAULT_COMMENT_PATTERN = /^no default$/iu;
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//------------------------------------------------------------------------------
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// Rule Definition
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//------------------------------------------------------------------------------
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module.exports = {
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meta: {
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type: "suggestion",
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docs: {
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description: "require `default` cases in `switch` statements",
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category: "Best Practices",
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recommended: false,
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url: "https://eslint.org/docs/rules/default-case"
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},
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schema: [{
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type: "object",
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properties: {
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commentPattern: {
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type: "string"
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}
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},
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additionalProperties: false
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}],
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messages: {
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missingDefaultCase: "Expected a default case."
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}
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},
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create(context) {
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const options = context.options[0] || {};
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const commentPattern = options.commentPattern
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? new RegExp(options.commentPattern, "u")
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: DEFAULT_COMMENT_PATTERN;
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const sourceCode = context.getSourceCode();
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//--------------------------------------------------------------------------
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// Helpers
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//--------------------------------------------------------------------------
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/**
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* Shortcut to get last element of array
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* @param {*[]} collection Array
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* @returns {*} Last element
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*/
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function last(collection) {
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return collection[collection.length - 1];
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}
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//--------------------------------------------------------------------------
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// Public
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//--------------------------------------------------------------------------
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return {
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SwitchStatement(node) {
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if (!node.cases.length) {
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/*
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* skip check of empty switch because there is no easy way
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* to extract comments inside it now
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*/
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return;
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}
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const hasDefault = node.cases.some(v => v.test === null);
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if (!hasDefault) {
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let comment;
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const lastCase = last(node.cases);
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const comments = sourceCode.getCommentsAfter(lastCase);
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if (comments.length) {
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comment = last(comments);
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}
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if (!comment || !commentPattern.test(comment.value.trim())) {
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context.report({ node, messageId: "missingDefaultCase" });
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}
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}
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}
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};
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}
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};
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