4 * Copyright 2019 Palantir Technologies, Inc.
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at
10 * http://www.apache.org/licenses/LICENSE-2.0
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
18 Object.defineProperty(exports, "__esModule", { value: true });
19 var tslib_1 = require("tslib");
20 var tsutils_1 = require("tsutils");
21 var ts = require("typescript");
22 var Lint = require("../index");
23 var Rule = /** @class */ (function (_super) {
24 tslib_1.__extends(Rule, _super);
26 return _super !== null && _super.apply(this, arguments) || this;
28 Rule.FAILURE_STRING_FACTORY = function () {
29 return "Use a for...of statement instead of for...in. If iterating over an object, use Object.keys() to access its enumerable keys.";
31 Rule.prototype.apply = function (sourceFile) {
32 return this.applyWithFunction(sourceFile, walk);
35 description: "Ban the usage of for...in statements.",
36 optionExamples: [true],
38 optionsDescription: "Not configurable.",
39 rationale: "for...in statements are legacy JavaScript syntax which usually require a verbose `hasOwnProperty` check inside their loop body. These statements can be fully replaced with for...of statements in modern JS & TS.",
40 ruleName: "no-for-in",
42 typescriptOnly: false,
45 }(Lint.Rules.AbstractRule));
49 if (tsutils_1.isForInStatement(node)) {
50 var msg = Rule.FAILURE_STRING_FACTORY();
51 ctx.addFailureAt(node.getStart(), node.getWidth(), msg);
53 return ts.forEachChild(node, cb);
55 return ts.forEachChild(ctx.sourceFile, cb);