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 tsutils_1 = require("tsutils");
21 var ts = require("typescript");
22 var Lint = require("../index");
23 var utils_1 = require("../utils");
24 var Rule = /** @class */ (function (_super) {
25 tslib_1.__extends(Rule, _super);
27 return _super !== null && _super.apply(this, arguments) || this;
29 Rule.prototype.applyWithProgram = function (sourceFile, program) {
30 return this.applyWithFunction(sourceFile, walk, undefined, program.getTypeChecker());
32 /* tslint:disable:object-literal-sort-keys */
34 ruleName: "use-default-type-parameter",
35 description: "Warns if an explicitly specified type argument is the default for that type parameter.",
36 optionsDescription: "Not configurable.",
38 optionExamples: ["true"],
39 type: "functionality",
41 requiresTypeInfo: true,
43 /* tslint:enable:object-literal-sort-keys */
44 Rule.FAILURE_STRING = "This is the default value for this type parameter, so it can be omitted.";
46 }(Lint.Rules.TypedRule));
48 function walk(ctx, checker) {
49 return ts.forEachChild(ctx.sourceFile, function cb(node) {
50 var argsAndParams = getArgsAndParameters(node, checker);
51 if (argsAndParams !== undefined) {
52 checkArgsAndParameters(argsAndParams);
54 return ts.forEachChild(node, cb);
56 function checkArgsAndParameters(_a) {
57 var typeArguments = _a.typeArguments, typeParameters = _a.typeParameters;
58 // Just check the last one. Must specify previous type parameters if the last one is specified.
59 var i = typeArguments.length - 1;
60 var arg = typeArguments[i];
61 var param = typeParameters[i];
62 // TODO: would like checker.areTypesEquivalent. https://github.com/Microsoft/TypeScript/issues/13502
63 if (param.default !== undefined && param.default.getText() === arg.getText()) {
64 ctx.addFailureAtNode(arg, Rule.FAILURE_STRING, createFix());
66 function createFix() {
68 return Lint.Replacement.deleteFromTo(typeArguments.pos - 1, typeArguments.end + 1);
71 return Lint.Replacement.deleteFromTo(typeArguments[i - 1].end, arg.end);
76 function getArgsAndParameters(node, checker) {
78 case ts.SyntaxKind.CallExpression:
79 case ts.SyntaxKind.NewExpression:
80 case ts.SyntaxKind.TypeReference:
81 case ts.SyntaxKind.ExpressionWithTypeArguments:
83 var typeArguments = decl.typeArguments;
84 if (typeArguments === undefined) {
87 var typeParameters = decl.kind === ts.SyntaxKind.TypeReference
88 ? typeParamsFromType(decl.typeName, checker)
89 : decl.kind === ts.SyntaxKind.ExpressionWithTypeArguments
90 ? typeParamsFromType(decl.expression, checker)
91 : typeParamsFromCall(node, checker);
92 return typeParameters === undefined ? undefined : { typeArguments: typeArguments, typeParameters: typeParameters };
97 function typeParamsFromCall(node, checker) {
98 var sig = checker.getResolvedSignature(node);
99 var sigDecl = sig === undefined ? undefined : sig.getDeclaration();
100 if (sigDecl === undefined) {
101 return node.kind === ts.SyntaxKind.NewExpression
102 ? typeParamsFromType(node.expression, checker)
105 return sigDecl.typeParameters === undefined ? undefined : sigDecl.typeParameters;
107 function typeParamsFromType(type, checker) {
108 var sym = getAliasedSymbol(checker.getSymbolAtLocation(type), checker);
109 if (sym === undefined || sym.declarations === undefined) {
112 return utils_1.find(sym.declarations, function (decl) {
113 return tsutils_1.isClassLikeDeclaration(decl) || tsutils_1.isTypeAliasDeclaration(decl) || tsutils_1.isInterfaceDeclaration(decl)
114 ? decl.typeParameters
118 function getAliasedSymbol(symbol, checker) {
119 if (symbol === undefined) {
122 return tsutils_1.isSymbolFlagSet(symbol, ts.SymbolFlags.Alias)
123 ? checker.getAliasedSymbol(symbol)