eslint-plugin-sonarjs
Version:
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JavaScript
;
/*
* SonarQube JavaScript Plugin
* Copyright (C) SonarSource Sàrl
* mailto:info AT sonarsource DOT com
*
* You can redistribute and/or modify this program under the terms of
* the Sonar Source-Available License Version 1, as published by SonarSource Sàrl.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the Sonar Source-Available License for more details.
*
* You should have received a copy of the Sonar Source-Available License
* along with this program; if not, see https://sonarsource.com/license/ssal/
*/
// https://sonarsource.github.io/rspec/#/rspec/S3403/javascript
var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
if (k2 === undefined) k2 = k;
var desc = Object.getOwnPropertyDescriptor(m, k);
if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
desc = { enumerable: true, get: function() { return m[k]; } };
}
Object.defineProperty(o, k2, desc);
}) : (function(o, m, k, k2) {
if (k2 === undefined) k2 = k;
o[k2] = m[k];
}));
var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
Object.defineProperty(o, "default", { enumerable: true, value: v });
}) : function(o, v) {
o["default"] = v;
});
var __importStar = (this && this.__importStar) || (function () {
var ownKeys = function(o) {
ownKeys = Object.getOwnPropertyNames || function (o) {
var ar = [];
for (var k in o) if (Object.prototype.hasOwnProperty.call(o, k)) ar[ar.length] = k;
return ar;
};
return ownKeys(o);
};
return function (mod) {
if (mod && mod.__esModule) return mod;
var result = {};
if (mod != null) for (var k = ownKeys(mod), i = 0; i < k.length; i++) if (k[i] !== "default") __createBinding(result, mod, k[i]);
__setModuleDefault(result, mod);
return result;
};
})();
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.rule = void 0;
const typescript_1 = __importDefault(require("typescript"));
const generate_meta_js_1 = require("../helpers/generate-meta.js");
const type_js_1 = require("../helpers/type.js");
const parser_services_js_1 = require("../helpers/parser-services.js");
const location_js_1 = require("../helpers/location.js");
const meta = __importStar(require("./generated-meta.js"));
exports.rule = {
meta: (0, generate_meta_js_1.generateMeta)(meta, { hasSuggestions: true }),
create(context) {
const services = context.sourceCode.parserServices;
if (!(0, parser_services_js_1.isRequiredParserServices)(services)) {
return {};
}
function isComparableTo(lhs, rhs) {
const checker = services.program.getTypeChecker();
const lhsType = checker.getBaseTypeOfLiteralType((0, type_js_1.getTypeFromTreeNode)(lhs, services));
const rhsType = checker.getBaseTypeOfLiteralType((0, type_js_1.getTypeFromTreeNode)(rhs, services));
// If either type is indeterminate (unknown, type parameter, or indexed access),
// we cannot know at compile time if the comparison will always fail
if (isIndeterminateType(lhsType) || isIndeterminateType(rhsType)) {
return true;
}
// @ts-ignore private API
return (checker.isTypeAssignableTo(lhsType, rhsType) || checker.isTypeAssignableTo(rhsType, lhsType));
}
return {
BinaryExpression: (node) => {
const { left, operator, right } = node;
if (['===', '!=='].includes(operator) && !isComparableTo(left, right)) {
const [actual, expected, outcome] = operator === '===' ? ['===', '==', 'false'] : ['!==', '!=', 'true'];
const operatorToken = context.sourceCode
.getTokensBetween(left, right)
.find(token => token.type === 'Punctuator' && token.value === operator);
(0, location_js_1.report)(context, {
message: `Remove this "${actual}" check; it will always be ${outcome}. Did you mean to use "${expected}"?`,
loc: operatorToken.loc,
suggest: [
{
desc: `Replace "${actual}" with "${expected}"`,
fix: fixer => fixer.replaceText(operatorToken, expected),
},
],
}, [left, right].map(node => (0, location_js_1.toSecondaryLocation)(node)));
}
},
};
},
};
/**
* Checks if a type is indeterminate (its actual value cannot be determined at compile time).
* - Unknown: can be compared with anything
* - TypeParameter: generics like T
* - IndexedAccess: like T[K]
*/
function isIndeterminateType(type) {
const indeterminateFlags = typescript_1.default.TypeFlags.Unknown | typescript_1.default.TypeFlags.TypeParameter | typescript_1.default.TypeFlags.IndexedAccess;
return (type.flags & indeterminateFlags) !== 0;
}