4 * Copyright 2013 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 utils = 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 /* tslint:enable:object-literal-sort-keys */
29 Rule.FAILURE_STRING = function (keyword) {
30 return "expected a 'break' before '" + ts.tokenToString(keyword) + "'";
32 Rule.prototype.apply = function (sourceFile) {
33 return this.applyWithWalker(new NoSwitchCaseFallThroughWalker(sourceFile, this.ruleName, undefined));
35 /* tslint:disable:object-literal-sort-keys */
37 ruleName: "no-switch-case-fall-through",
38 description: "Disallows falling through case statements.",
39 descriptionDetails: Lint.Utils.dedent(templateObject_1 || (templateObject_1 = tslib_1.__makeTemplateObject(["\n For example, the following is not allowed:\n\n ```ts\n switch(foo) {\n case 1:\n someFunc(foo);\n case 2:\n someOtherFunc(foo);\n }\n ```\n\n However, fall through is allowed when case statements are consecutive or\n a magic `/* falls through */` comment is present. The following is valid:\n\n ```ts\n switch(foo) {\n case 1:\n someFunc(foo);\n /* falls through */\n case 2:\n case 3:\n someOtherFunc(foo);\n }\n ```"], ["\n For example, the following is not allowed:\n\n \\`\\`\\`ts\n switch(foo) {\n case 1:\n someFunc(foo);\n case 2:\n someOtherFunc(foo);\n }\n \\`\\`\\`\n\n However, fall through is allowed when case statements are consecutive or\n a magic \\`/* falls through */\\` comment is present. The following is valid:\n\n \\`\\`\\`ts\n switch(foo) {\n case 1:\n someFunc(foo);\n /* falls through */\n case 2:\n case 3:\n someOtherFunc(foo);\n }\n \\`\\`\\`"]))),
40 rationale: "Fall though in switch statements is often unintentional and a bug.",
41 optionsDescription: "Not configurable.",
43 optionExamples: [true],
44 type: "functionality",
45 typescriptOnly: false,
48 }(Lint.Rules.AbstractRule));
50 var NoSwitchCaseFallThroughWalker = /** @class */ (function (_super) {
51 tslib_1.__extends(NoSwitchCaseFallThroughWalker, _super);
52 function NoSwitchCaseFallThroughWalker() {
53 return _super !== null && _super.apply(this, arguments) || this;
55 NoSwitchCaseFallThroughWalker.prototype.walk = function (sourceFile) {
57 var cb = function (node) {
58 if (utils.isSwitchStatement(node)) {
59 _this.visitSwitchStatement(node);
61 return ts.forEachChild(node, cb);
63 return ts.forEachChild(sourceFile, cb);
65 NoSwitchCaseFallThroughWalker.prototype.visitSwitchStatement = function (_a) {
67 var clauses = _a.caseBlock.clauses;
68 clauses.forEach(function (clause, i) {
69 if (i !== clauses.length - 1 &&
70 clause.statements.length !== 0 &&
71 !utils.endsControlFlow(clause) &&
72 !_this.isFallThroughAllowed(clause)) {
73 var keyword = clauses[i + 1].getChildAt(0);
74 _this.addFailureAtNode(keyword, Rule.FAILURE_STRING(keyword.kind));
78 NoSwitchCaseFallThroughWalker.prototype.isFallThroughAllowed = function (clause) {
80 var comments = ts.getLeadingCommentRanges(this.sourceFile.text, clause.end);
81 return (comments !== undefined &&
82 comments.some(function (comment) {
83 return /^\s*falls through\b/i.test(_this.sourceFile.text.slice(comment.pos + 2, comment.end));
86 return NoSwitchCaseFallThroughWalker;
87 }(Lint.AbstractWalker));
88 exports.NoSwitchCaseFallThroughWalker = NoSwitchCaseFallThroughWalker;