102 lines
4.7 KiB
JavaScript
102 lines
4.7 KiB
JavaScript
/**
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* @license
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* Copyright 2013 Palantir Technologies, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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"use strict";
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var __extends = (this && this.__extends) || (function () {
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var extendStatics = Object.setPrototypeOf ||
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({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
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function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
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return function (d, b) {
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extendStatics(d, b);
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function __() { this.constructor = d; }
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d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
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};
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})();
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Object.defineProperty(exports, "__esModule", { value: true });
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var ts = require("typescript");
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var Lint = require("../index");
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var OPTION_ALLOW_DECLARATIONS = "allow-declarations";
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var OPTION_ALLOW_NAMED_FUNCTIONS = "allow-named-functions";
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var Rule = (function (_super) {
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__extends(Rule, _super);
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function Rule() {
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return _super !== null && _super.apply(this, arguments) || this;
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}
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Rule.prototype.apply = function (sourceFile) {
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return this.applyWithWalker(new OnlyArrowFunctionsWalker(sourceFile, this.getOptions()));
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};
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return Rule;
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}(Lint.Rules.AbstractRule));
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/* tslint:disable:object-literal-sort-keys */
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Rule.metadata = {
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ruleName: "only-arrow-functions",
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description: "Disallows traditional (non-arrow) function expressions.",
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rationale: "Traditional functions don't bind lexical scope, which can lead to unexpected behavior when accessing 'this'.",
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optionsDescription: (_a = ["\n Two arguments may be optionally provided:\n\n * `\"", "\"` allows standalone function declarations.\n * `\"", "\"` allows the expression `function foo() {}` but not `function() {}`.\n "], _a.raw = ["\n Two arguments may be optionally provided:\n\n * \\`\"", "\"\\` allows standalone function declarations.\n * \\`\"", "\"\\` allows the expression \\`function foo() {}\\` but not \\`function() {}\\`.\n "], Lint.Utils.dedent(_a, OPTION_ALLOW_DECLARATIONS, OPTION_ALLOW_NAMED_FUNCTIONS)),
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options: {
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type: "array",
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items: {
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type: "string",
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enum: [OPTION_ALLOW_DECLARATIONS, OPTION_ALLOW_NAMED_FUNCTIONS],
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},
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minLength: 0,
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maxLength: 1,
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},
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optionExamples: ["true", "[true, \"" + OPTION_ALLOW_DECLARATIONS + "\", \"" + OPTION_ALLOW_NAMED_FUNCTIONS + "\"]"],
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type: "typescript",
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typescriptOnly: false,
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};
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/* tslint:enable:object-literal-sort-keys */
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Rule.FAILURE_STRING = "non-arrow functions are forbidden";
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exports.Rule = Rule;
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var OnlyArrowFunctionsWalker = (function (_super) {
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__extends(OnlyArrowFunctionsWalker, _super);
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function OnlyArrowFunctionsWalker(sourceFile, options) {
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var _this = _super.call(this, sourceFile, options) || this;
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_this.allowDeclarations = _this.hasOption(OPTION_ALLOW_DECLARATIONS);
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_this.allowNamedFunctions = _this.hasOption(OPTION_ALLOW_NAMED_FUNCTIONS);
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return _this;
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}
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OnlyArrowFunctionsWalker.prototype.visitFunctionDeclaration = function (node) {
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if (!this.allowDeclarations && !this.allowNamedFunctions) {
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this.failUnlessExempt(node);
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}
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_super.prototype.visitFunctionDeclaration.call(this, node);
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};
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OnlyArrowFunctionsWalker.prototype.visitFunctionExpression = function (node) {
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if (node.name === undefined || !this.allowNamedFunctions) {
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this.failUnlessExempt(node);
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}
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_super.prototype.visitFunctionExpression.call(this, node);
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};
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OnlyArrowFunctionsWalker.prototype.failUnlessExempt = function (node) {
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if (!functionIsExempt(node)) {
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this.addFailureAtNode(Lint.childOfKind(node, ts.SyntaxKind.FunctionKeyword), Rule.FAILURE_STRING);
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}
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};
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return OnlyArrowFunctionsWalker;
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}(Lint.RuleWalker));
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/** Generator functions and functions explicitly declaring `this` are allowed. */
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function functionIsExempt(node) {
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return node.asteriskToken || hasThisParameter(node);
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}
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function hasThisParameter(node) {
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var first = node.parameters[0];
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return first && first.name.kind === ts.SyntaxKind.Identifier &&
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first.name.originalKeywordKind === ts.SyntaxKind.ThisKeyword;
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}
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var _a;
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