Spaces:
Runtime error
Runtime error
File size: 7,704 Bytes
4a51346 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 |
/**
* @fileoverview Rule to require parens in arrow function arguments.
* @author Jxck
*/
"use strict";
//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------
const astUtils = require("./utils/ast-utils");
//------------------------------------------------------------------------------
// Helpers
//------------------------------------------------------------------------------
/**
* Determines if the given arrow function has block body.
* @param {ASTNode} node `ArrowFunctionExpression` node.
* @returns {boolean} `true` if the function has block body.
*/
function hasBlockBody(node) {
return node.body.type === "BlockStatement";
}
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
module.exports = {
meta: {
type: "layout",
docs: {
description: "require parentheses around arrow function arguments",
category: "ECMAScript 6",
recommended: false,
url: "https://eslint.org/docs/rules/arrow-parens"
},
fixable: "code",
schema: [
{
enum: ["always", "as-needed"]
},
{
type: "object",
properties: {
requireForBlockBody: {
type: "boolean",
default: false
}
},
additionalProperties: false
}
],
messages: {
unexpectedParens: "Unexpected parentheses around single function argument.",
expectedParens: "Expected parentheses around arrow function argument.",
unexpectedParensInline: "Unexpected parentheses around single function argument having a body with no curly braces.",
expectedParensBlock: "Expected parentheses around arrow function argument having a body with curly braces."
}
},
create(context) {
const asNeeded = context.options[0] === "as-needed";
const requireForBlockBody = asNeeded && context.options[1] && context.options[1].requireForBlockBody === true;
const sourceCode = context.getSourceCode();
/**
* Finds opening paren of parameters for the given arrow function, if it exists.
* It is assumed that the given arrow function has exactly one parameter.
* @param {ASTNode} node `ArrowFunctionExpression` node.
* @returns {Token|null} the opening paren, or `null` if the given arrow function doesn't have parens of parameters.
*/
function findOpeningParenOfParams(node) {
const tokenBeforeParams = sourceCode.getTokenBefore(node.params[0]);
if (
tokenBeforeParams &&
astUtils.isOpeningParenToken(tokenBeforeParams) &&
node.range[0] <= tokenBeforeParams.range[0]
) {
return tokenBeforeParams;
}
return null;
}
/**
* Finds closing paren of parameters for the given arrow function.
* It is assumed that the given arrow function has parens of parameters and that it has exactly one parameter.
* @param {ASTNode} node `ArrowFunctionExpression` node.
* @returns {Token} the closing paren of parameters.
*/
function getClosingParenOfParams(node) {
return sourceCode.getTokenAfter(node.params[0], astUtils.isClosingParenToken);
}
/**
* Determines whether the given arrow function has comments inside parens of parameters.
* It is assumed that the given arrow function has parens of parameters.
* @param {ASTNode} node `ArrowFunctionExpression` node.
* @param {Token} openingParen Opening paren of parameters.
* @returns {boolean} `true` if the function has at least one comment inside of parens of parameters.
*/
function hasCommentsInParensOfParams(node, openingParen) {
return sourceCode.commentsExistBetween(openingParen, getClosingParenOfParams(node));
}
/**
* Determines whether the given arrow function has unexpected tokens before opening paren of parameters,
* in which case it will be assumed that the existing parens of parameters are necessary.
* Only tokens within the range of the arrow function (tokens that are part of the arrow function) are taken into account.
* Example: <T>(a) => b
* @param {ASTNode} node `ArrowFunctionExpression` node.
* @param {Token} openingParen Opening paren of parameters.
* @returns {boolean} `true` if the function has at least one unexpected token.
*/
function hasUnexpectedTokensBeforeOpeningParen(node, openingParen) {
const expectedCount = node.async ? 1 : 0;
return sourceCode.getFirstToken(node, { skip: expectedCount }) !== openingParen;
}
return {
"ArrowFunctionExpression[params.length=1]"(node) {
const shouldHaveParens = !asNeeded || requireForBlockBody && hasBlockBody(node);
const openingParen = findOpeningParenOfParams(node);
const hasParens = openingParen !== null;
const [param] = node.params;
if (shouldHaveParens && !hasParens) {
context.report({
node,
messageId: requireForBlockBody ? "expectedParensBlock" : "expectedParens",
loc: param.loc,
*fix(fixer) {
yield fixer.insertTextBefore(param, "(");
yield fixer.insertTextAfter(param, ")");
}
});
}
if (
!shouldHaveParens &&
hasParens &&
param.type === "Identifier" &&
!param.typeAnnotation &&
!node.returnType &&
!hasCommentsInParensOfParams(node, openingParen) &&
!hasUnexpectedTokensBeforeOpeningParen(node, openingParen)
) {
context.report({
node,
messageId: requireForBlockBody ? "unexpectedParensInline" : "unexpectedParens",
loc: param.loc,
*fix(fixer) {
const tokenBeforeOpeningParen = sourceCode.getTokenBefore(openingParen);
const closingParen = getClosingParenOfParams(node);
if (
tokenBeforeOpeningParen &&
tokenBeforeOpeningParen.range[1] === openingParen.range[0] &&
!astUtils.canTokensBeAdjacent(tokenBeforeOpeningParen, sourceCode.getFirstToken(param))
) {
yield fixer.insertTextBefore(openingParen, " ");
}
// remove parens, whitespace inside parens, and possible trailing comma
yield fixer.removeRange([openingParen.range[0], param.range[0]]);
yield fixer.removeRange([param.range[1], closingParen.range[1]]);
}
});
}
}
};
}
};
|