noSwitchCaseFallThroughRule.js 5.1KB

12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788
  1. "use strict";
  2. /**
  3. * @license
  4. * Copyright 2013 Palantir Technologies, Inc.
  5. *
  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
  9. *
  10. * http://www.apache.org/licenses/LICENSE-2.0
  11. *
  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.
  17. */
  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);
  25. function Rule() {
  26. return _super !== null && _super.apply(this, arguments) || this;
  27. }
  28. /* tslint:enable:object-literal-sort-keys */
  29. Rule.FAILURE_STRING = function (keyword) {
  30. return "expected a 'break' before '" + ts.tokenToString(keyword) + "'";
  31. };
  32. Rule.prototype.apply = function (sourceFile) {
  33. return this.applyWithWalker(new NoSwitchCaseFallThroughWalker(sourceFile, this.ruleName, undefined));
  34. };
  35. /* tslint:disable:object-literal-sort-keys */
  36. Rule.metadata = {
  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.",
  42. options: null,
  43. optionExamples: [true],
  44. type: "functionality",
  45. typescriptOnly: false,
  46. };
  47. return Rule;
  48. }(Lint.Rules.AbstractRule));
  49. exports.Rule = Rule;
  50. var NoSwitchCaseFallThroughWalker = /** @class */ (function (_super) {
  51. tslib_1.__extends(NoSwitchCaseFallThroughWalker, _super);
  52. function NoSwitchCaseFallThroughWalker() {
  53. return _super !== null && _super.apply(this, arguments) || this;
  54. }
  55. NoSwitchCaseFallThroughWalker.prototype.walk = function (sourceFile) {
  56. var _this = this;
  57. var cb = function (node) {
  58. if (utils.isSwitchStatement(node)) {
  59. _this.visitSwitchStatement(node);
  60. }
  61. return ts.forEachChild(node, cb);
  62. };
  63. return ts.forEachChild(sourceFile, cb);
  64. };
  65. NoSwitchCaseFallThroughWalker.prototype.visitSwitchStatement = function (_a) {
  66. var _this = this;
  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));
  75. }
  76. });
  77. };
  78. NoSwitchCaseFallThroughWalker.prototype.isFallThroughAllowed = function (clause) {
  79. var _this = this;
  80. var comments = ts.getLeadingCommentRanges(this.sourceFile.text, clause.end);
  81. return comments !== undefined &&
  82. comments.some(function (comment) { return /^\s*falls through\b/i.test(_this.sourceFile.text.slice(comment.pos + 2, comment.end)); });
  83. };
  84. return NoSwitchCaseFallThroughWalker;
  85. }(Lint.AbstractWalker));
  86. exports.NoSwitchCaseFallThroughWalker = NoSwitchCaseFallThroughWalker;
  87. var templateObject_1;