112 lines
3.2 KiB
JavaScript
112 lines
3.2 KiB
JavaScript
|
/**
|
||
|
|
* @fileoverview Rule to
|
||
|
|
* @author Toru Nagashima
|
||
|
|
*/
|
||
|
|
|
||
|
|
"use strict";
|
||
|
|
|
||
|
|
//------------------------------------------------------------------------------
|
||
|
|
// Helpers
|
||
|
|
//------------------------------------------------------------------------------
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Gets the variable object of `arguments` which is defined implicitly.
|
||
|
|
* @param {eslint-scope.Scope} scope A scope to get.
|
||
|
|
* @returns {eslint-scope.Variable} The found variable object.
|
||
|
|
*/
|
||
|
|
function getVariableOfArguments(scope) {
|
||
|
|
const variables = scope.variables;
|
||
|
|
|
||
|
|
for (let i = 0; i < variables.length; ++i) {
|
||
|
|
const variable = variables[i];
|
||
|
|
|
||
|
|
if (variable.name === "arguments") {
|
||
|
|
|
||
|
|
/*
|
||
|
|
* If there was a parameter which is named "arguments", the implicit "arguments" is not defined.
|
||
|
|
* So does fast return with null.
|
||
|
|
*/
|
||
|
|
return (variable.identifiers.length === 0) ? variable : null;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/* istanbul ignore next : unreachable */
|
||
|
|
return null;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Checks if the given reference is not normal member access.
|
||
|
|
*
|
||
|
|
* - arguments .... true // not member access
|
||
|
|
* - arguments[i] .... true // computed member access
|
||
|
|
* - arguments[0] .... true // computed member access
|
||
|
|
* - arguments.length .... false // normal member access
|
||
|
|
* @param {eslint-scope.Reference} reference The reference to check.
|
||
|
|
* @returns {boolean} `true` if the reference is not normal member access.
|
||
|
|
*/
|
||
|
|
function isNotNormalMemberAccess(reference) {
|
||
|
|
const id = reference.identifier;
|
||
|
|
const parent = id.parent;
|
||
|
|
|
||
|
|
return !(
|
||
|
|
parent.type === "MemberExpression" &&
|
||
|
|
parent.object === id &&
|
||
|
|
!parent.computed
|
||
|
|
);
|
||
|
|
}
|
||
|
|
|
||
|
|
//------------------------------------------------------------------------------
|
||
|
|
// Rule Definition
|
||
|
|
//------------------------------------------------------------------------------
|
||
|
|
|
||
|
|
module.exports = {
|
||
|
|
meta: {
|
||
|
|
type: "suggestion",
|
||
|
|
|
||
|
|
docs: {
|
||
|
|
description: "require rest parameters instead of `arguments`",
|
||
|
|
category: "ECMAScript 6",
|
||
|
|
recommended: false,
|
||
|
|
url: "https://eslint.org/docs/rules/prefer-rest-params"
|
||
|
|
},
|
||
|
|
|
||
|
|
schema: []
|
||
|
|
},
|
||
|
|
|
||
|
|
create(context) {
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Reports a given reference.
|
||
|
|
* @param {eslint-scope.Reference} reference A reference to report.
|
||
|
|
* @returns {void}
|
||
|
|
*/
|
||
|
|
function report(reference) {
|
||
|
|
context.report({
|
||
|
|
node: reference.identifier,
|
||
|
|
loc: reference.identifier.loc,
|
||
|
|
message: "Use the rest parameters instead of 'arguments'."
|
||
|
|
});
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Reports references of the implicit `arguments` variable if exist.
|
||
|
|
* @returns {void}
|
||
|
|
*/
|
||
|
|
function checkForArguments() {
|
||
|
|
const argumentsVar = getVariableOfArguments(context.getScope());
|
||
|
|
|
||
|
|
if (argumentsVar) {
|
||
|
|
argumentsVar
|
||
|
|
.references
|
||
|
|
.filter(isNotNormalMemberAccess)
|
||
|
|
.forEach(report);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return {
|
||
|
|
"FunctionDeclaration:exit": checkForArguments,
|
||
|
|
"FunctionExpression:exit": checkForArguments
|
||
|
|
};
|
||
|
|
}
|
||
|
|
};
|