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"use strict";
/**
* @license
* Copyright 2013 Palantir Technologies, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
Object.defineProperty(exports, "__esModule", { value: true });
var tslib_1 = require("tslib");
var utils = require("tsutils");
var ts = require("typescript");
var Lint = require("../index");
var OPTION_ALLOW_DECLARATIONS = "allow-declarations";
var OPTION_ALLOW_NAMED_FUNCTIONS = "allow-named-functions";
var Rule = (function (_super) {
tslib_1.__extends(Rule, _super);
function Rule() {
return _super !== null && _super.apply(this, arguments) || this;
}
Rule.prototype.apply = function (sourceFile) {
return this.applyWithFunction(sourceFile, walk, parseOptions(this.ruleArguments));
};
return Rule;
}(Lint.Rules.AbstractRule));
/* tslint:disable:object-literal-sort-keys */
Rule.metadata = {
ruleName: "only-arrow-functions",
description: "Disallows traditional (non-arrow) function expressions.",
rationale: "Traditional functions don't bind lexical scope, which can lead to unexpected behavior when accessing 'this'.",
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)),
options: {
type: "array",
items: {
type: "string",
enum: [OPTION_ALLOW_DECLARATIONS, OPTION_ALLOW_NAMED_FUNCTIONS],
},
minLength: 0,
maxLength: 1,
},
optionExamples: [true, [true, OPTION_ALLOW_DECLARATIONS, OPTION_ALLOW_NAMED_FUNCTIONS]],
type: "typescript",
typescriptOnly: false,
};
/* tslint:enable:object-literal-sort-keys */
Rule.FAILURE_STRING = "non-arrow functions are forbidden";
exports.Rule = Rule;
function parseOptions(ruleArguments) {
return {
allowDeclarations: hasOption(OPTION_ALLOW_DECLARATIONS),
allowNamedFunctions: hasOption(OPTION_ALLOW_NAMED_FUNCTIONS),
};
function hasOption(name) {
return ruleArguments.indexOf(name) !== -1;
}
}
function walk(ctx) {
var sourceFile = ctx.sourceFile, _a = ctx.options, allowDeclarations = _a.allowDeclarations, allowNamedFunctions = _a.allowNamedFunctions;
return ts.forEachChild(sourceFile, function cb(node) {
switch (node.kind) {
case ts.SyntaxKind.FunctionDeclaration:
if (allowDeclarations) {
break;
}
// falls through
case ts.SyntaxKind.FunctionExpression: {
var f = node;
if (!(allowNamedFunctions && f.name !== undefined) && !functionIsExempt(f)) {
ctx.addFailureAtNode(Lint.childOfKind(node, ts.SyntaxKind.FunctionKeyword), Rule.FAILURE_STRING);
}
}
}
return ts.forEachChild(node, cb);
});
}
/** Generator functions and functions using `this` are allowed. */
function functionIsExempt(node) {
return node.asteriskToken !== undefined || hasThisParameter(node) || node.body !== undefined && usesThisInBody(node.body);
}
function hasThisParameter(node) {
var first = node.parameters[0];
return first !== undefined && first.name.kind === ts.SyntaxKind.Identifier &&
first.name.originalKeywordKind === ts.SyntaxKind.ThisKeyword;
}
function usesThisInBody(node) {
return node.kind === ts.SyntaxKind.ThisKeyword || !utils.hasOwnThisReference(node) && ts.forEachChild(node, usesThisInBody);
}
var _a;
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