@rushstack/eslint-plugin
Version:
An ESLint plugin providing supplementary rules for use with the @rushstack/eslint-config package
86 lines • 4.24 kB
JavaScript
;
// Copyright (c) Microsoft Corporation. All rights reserved. Licensed under the MIT license.
// See LICENSE in the project root for license information.
Object.defineProperty(exports, "__esModule", { value: true });
exports.noUntypedUnderscoreRule = void 0;
const noUntypedUnderscoreRule = {
defaultOptions: [],
meta: {
type: 'problem',
messages: {
'error-untyped-underscore': 'This expression appears to access a private member "{{memberName}}"; ' +
'either remove the underscore prefix or else declare a type for the containing object'
},
schema: [],
docs: {
description: 'Prevent TypeScript code from accessing legacy JavaScript members' +
' whose names have an underscore prefix',
recommended: 'strict',
url: 'https://www.npmjs.com/package/@rushstack/eslint-plugin'
}
},
create: (context) => {
const parserServices = context.parserServices;
if (!parserServices || !parserServices.program || !parserServices.esTreeNodeToTSNodeMap) {
throw new Error('This rule requires your ESLint configuration to define the "parserOptions.project"' +
' property for "@typescript-eslint/parser".');
}
const typeChecker = parserServices.program.getTypeChecker();
return {
MemberExpression: function (node) {
// Is it an expression like "x.y"?
// Ignore expressions such as "super.y", "this.y", and "that.y"
const memberObject = node.object;
if (memberObject) {
if (memberObject.type === 'Super' || memberObject.type === 'ThisExpression') {
return; // no match
}
if (memberObject.type === 'Identifier') {
if (memberObject.name === 'this' || memberObject.name === 'that') {
return; // no match
}
}
}
// Does the member name start with an underscore? (e.g. "x._y")
if (node.property && node.property.type === 'Identifier') {
const memberName = node.property.name;
if (memberName && memberName[0] === '_') {
// Do we have type information for the property (e.g. "_y")?
//
// Examples where propertyType is defined:
//
// let x: { _y: any };
// let x: {
// _y: boolean;
// [key: string]: number;
// };
//
// Examples with propertyType=undefined:
// let x: any;
// let x: { [key: string]: number };
//
let propertyType = undefined;
const memberObjectNode = parserServices.esTreeNodeToTSNodeMap.get(node.object);
if (memberObjectNode) {
const memberObjectType = typeChecker.getTypeAtLocation(memberObjectNode);
if (memberObjectType) {
propertyType = memberObjectType.getProperty(memberName);
}
}
// TypeScript's type system already sufficiently restricts access to private members.
// Thus, this ESLint rule only considers untyped code such as a legacy JavaScript API.
if (!propertyType) {
context.report({
node,
messageId: 'error-untyped-underscore',
data: { memberName: memberName }
});
}
}
}
}
};
}
};
exports.noUntypedUnderscoreRule = noUntypedUnderscoreRule;
//# sourceMappingURL=no-untyped-underscore.js.map