You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
64 lines
2.1 KiB
64 lines
2.1 KiB
/** |
|
* @fileoverview Disallow shadowing of NaN, undefined, and Infinity (ES5 section 15.1.1) |
|
* @author Michael Ficarra |
|
*/ |
|
"use strict"; |
|
|
|
/** |
|
* Determines if a variable safely shadows undefined. |
|
* This is the case when a variable named `undefined` is never assigned to a value (i.e. it always shares the same value |
|
* as the global). |
|
* @param {eslintScope.Variable} variable The variable to check |
|
* @returns {boolean} true if this variable safely shadows `undefined` |
|
*/ |
|
function safelyShadowsUndefined(variable) { |
|
return variable.name === "undefined" && |
|
variable.references.every(ref => !ref.isWrite()) && |
|
variable.defs.every(def => def.node.type === "VariableDeclarator" && def.node.init === null); |
|
} |
|
|
|
//------------------------------------------------------------------------------ |
|
// Rule Definition |
|
//------------------------------------------------------------------------------ |
|
|
|
/** @type {import('../shared/types').Rule} */ |
|
module.exports = { |
|
meta: { |
|
type: "suggestion", |
|
|
|
docs: { |
|
description: "Disallow identifiers from shadowing restricted names", |
|
recommended: true, |
|
url: "https://eslint.org/docs/rules/no-shadow-restricted-names" |
|
}, |
|
|
|
schema: [], |
|
|
|
messages: { |
|
shadowingRestrictedName: "Shadowing of global property '{{name}}'." |
|
} |
|
}, |
|
|
|
create(context) { |
|
|
|
|
|
const RESTRICTED = new Set(["undefined", "NaN", "Infinity", "arguments", "eval"]); |
|
|
|
return { |
|
"VariableDeclaration, :function, CatchClause"(node) { |
|
for (const variable of context.getDeclaredVariables(node)) { |
|
if (variable.defs.length > 0 && RESTRICTED.has(variable.name) && !safelyShadowsUndefined(variable)) { |
|
context.report({ |
|
node: variable.defs[0].name, |
|
messageId: "shadowingRestrictedName", |
|
data: { |
|
name: variable.name |
|
} |
|
}); |
|
} |
|
} |
|
} |
|
}; |
|
|
|
} |
|
};
|
|
|