odin-javascript-exercises/node_modules/eslint/lib/rules/no-confusing-arrow.js
2017-12-15 12:56:14 -06:00

76 lines
2.3 KiB
JavaScript

/**
* @fileoverview A rule to warn against using arrow functions when they could be
* confused with comparisions
* @author Jxck <https://github.com/Jxck>
*/
"use strict";
const astUtils = require("../ast-utils.js");
//------------------------------------------------------------------------------
// Helpers
//------------------------------------------------------------------------------
/**
* Checks whether or not a node is a conditional expression.
* @param {ASTNode} node - node to test
* @returns {boolean} `true` if the node is a conditional expression.
*/
function isConditional(node) {
return node && node.type === "ConditionalExpression";
}
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
module.exports = {
meta: {
docs: {
description: "disallow arrow functions where they could be confused with comparisons",
category: "ECMAScript 6",
recommended: false
},
fixable: "code",
schema: [{
type: "object",
properties: {
allowParens: { type: "boolean" }
},
additionalProperties: false
}]
},
create(context) {
const config = context.options[0] || {};
const sourceCode = context.getSourceCode();
/**
* Reports if an arrow function contains an ambiguous conditional.
* @param {ASTNode} node - A node to check and report.
* @returns {void}
*/
function checkArrowFunc(node) {
const body = node.body;
if (isConditional(body) && !(config.allowParens && astUtils.isParenthesised(sourceCode, body))) {
context.report({
node,
message: "Arrow function used ambiguously with a conditional expression.",
fix(fixer) {
// if `allowParens` is not set to true dont bother wrapping in parens
return config.allowParens && fixer.replaceText(node.body, `(${sourceCode.getText(node.body)})`);
}
});
}
}
return {
ArrowFunctionExpression: checkArrowFunc
};
}
};