4 * Copyright 2017 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 ts = require("typescript");
21 var Lint = require("../index");
22 var Rule = /** @class */ (function (_super) {
23 tslib_1.__extends(Rule, _super);
25 return _super !== null && _super.apply(this, arguments) || this;
27 Rule.prototype.apply = function (sourceFile) {
28 return this.applyWithFunction(sourceFile, walk);
30 /* tslint:disable:object-literal-sort-keys */
32 ruleName: "no-non-null-assertion",
33 description: "Disallows non-null assertions using the `!` postfix operator.",
34 rationale: Lint.Utils.dedent(templateObject_1 || (templateObject_1 = tslib_1.__makeTemplateObject(["\n Using non-null assertion cancels the benefits of the strict null checking mode.\n\n Instead of assuming objects exist:\n\n ```\n function foo(instance: MyClass | undefined) {\n instance!.doWork();\n }\n ```\n\n Either inform the strict type system that the object must exist:\n\n ```\n function foo(instance: MyClass) {\n instance.doWork();\n }\n ```\n\n Or verify that the instance exists, which will inform the type checker:\n\n ```\n function foo(instance: MyClass | undefined) {\n if (instance !== undefined) {\n instance.doWork();\n }\n }\n ```\n "], ["\n Using non-null assertion cancels the benefits of the strict null checking mode.\n\n Instead of assuming objects exist:\n\n \\`\\`\\`\n function foo(instance: MyClass | undefined) {\n instance!.doWork();\n }\n \\`\\`\\`\n\n Either inform the strict type system that the object must exist:\n\n \\`\\`\\`\n function foo(instance: MyClass) {\n instance.doWork();\n }\n \\`\\`\\`\n\n Or verify that the instance exists, which will inform the type checker:\n\n \\`\\`\\`\n function foo(instance: MyClass | undefined) {\n if (instance !== undefined) {\n instance.doWork();\n }\n }\n \\`\\`\\`\n "]))),
35 optionsDescription: "Not configurable.",
37 optionExamples: [true],
41 /* tslint:enable:object-literal-sort-keys */
42 Rule.FAILURE_STRING = "Forbidden non null assertion";
44 }(Lint.Rules.AbstractRule));
47 return ts.forEachChild(ctx.sourceFile, function cb(node) {
48 if (node.kind === ts.SyntaxKind.NonNullExpression) {
49 ctx.addFailureAtNode(node, Rule.FAILURE_STRING);
51 return ts.forEachChild(node, cb);