blob: 1a2629a8ec95e84b96523b6e309f3c78535c8eda [file] [log] [blame]
/**
* @fileoverview Restrict usage of specified globals.
* @author BenoƮt Zugmeyer
*/
"use strict";
//------------------------------------------------------------------------------
// Helpers
//------------------------------------------------------------------------------
const DEFAULT_MESSAGE_TEMPLATE = "Unexpected use of '{{name}}'.",
CUSTOM_MESSAGE_TEMPLATE = "Unexpected use of '{{name}}'. {{customMessage}}";
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
module.exports = {
meta: {
type: "suggestion",
docs: {
description: "disallow specified global variables",
category: "Variables",
recommended: false,
url: "https://eslint.org/docs/rules/no-restricted-globals"
},
schema: {
type: "array",
items: {
oneOf: [
{
type: "string"
},
{
type: "object",
properties: {
name: { type: "string" },
message: { type: "string" }
},
required: ["name"],
additionalProperties: false
}
]
},
uniqueItems: true,
minItems: 0
}
},
create(context) {
// If no globals are restricted, we don't need to do anything
if (context.options.length === 0) {
return {};
}
const restrictedGlobalMessages = context.options.reduce((memo, option) => {
if (typeof option === "string") {
memo[option] = null;
} else {
memo[option.name] = option.message;
}
return memo;
}, {});
/**
* Report a variable to be used as a restricted global.
* @param {Reference} reference the variable reference
* @returns {void}
* @private
*/
function reportReference(reference) {
const name = reference.identifier.name,
customMessage = restrictedGlobalMessages[name],
message = customMessage
? CUSTOM_MESSAGE_TEMPLATE
: DEFAULT_MESSAGE_TEMPLATE;
context.report({
node: reference.identifier,
message,
data: {
name,
customMessage
}
});
}
/**
* Check if the given name is a restricted global name.
* @param {string} name name of a variable
* @returns {boolean} whether the variable is a restricted global or not
* @private
*/
function isRestricted(name) {
return Object.prototype.hasOwnProperty.call(restrictedGlobalMessages, name);
}
return {
Program() {
const scope = context.getScope();
// Report variables declared elsewhere (ex: variables defined as "global" by eslint)
scope.variables.forEach(variable => {
if (!variable.defs.length && isRestricted(variable.name)) {
variable.references.forEach(reportReference);
}
});
// Report variables not declared at all
scope.through.forEach(reference => {
if (isRestricted(reference.identifier.name)) {
reportReference(reference);
}
});
}
};
}
};