tslint
Version:
An extensible static analysis linter for the TypeScript language
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JavaScript
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/**
* @license
* Copyright 2018 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 });
exports.Rule = void 0;
var tslib_1 = require("tslib");
var tsutils_1 = require("tsutils");
var ts = require("typescript");
var Lint = require("../index");
var Rule = /** @class */ (function (_super) {
tslib_1.__extends(Rule, _super);
function Rule() {
return _super !== null && _super.apply(this, arguments) || this;
}
Rule.prototype.applyWithProgram = function (sourceFile, program) {
return this.applyWithWalker(new NoInferredEmptyObjectTypeRule(sourceFile, this.ruleName, program.getTypeChecker()));
};
/* tslint:disable:object-literal-sort-keys */
Rule.metadata = {
ruleName: "no-inferred-empty-object-type",
description: "Disallow type inference of {} (empty object type) at function and constructor call sites",
optionsDescription: "Not configurable.",
options: null,
optionExamples: [true],
rationale: Lint.Utils.dedent(templateObject_1 || (templateObject_1 = tslib_1.__makeTemplateObject(["\n Prior to TypeScript 3.4, generic type parameters for functions and constructors are inferred as\n `{}` (the empty object type) by default when no type parameter is explicitly supplied or when\n the compiler cannot infer a more specific type.\n This is often undesirable as the call is meant to be of a more specific type.\n "], ["\n Prior to TypeScript 3.4, generic type parameters for functions and constructors are inferred as\n \\`{}\\` (the empty object type) by default when no type parameter is explicitly supplied or when\n the compiler cannot infer a more specific type.\n This is often undesirable as the call is meant to be of a more specific type.\n "]))),
type: "functionality",
typescriptOnly: true,
requiresTypeInfo: true,
};
/* tslint:enable:object-literal-sort-keys */
Rule.EMPTY_INTERFACE_INSTANCE = "Explicit type parameter needs to be provided to the constructor";
Rule.EMPTY_INTERFACE_FUNCTION = "Explicit type parameter needs to be provided to the function call";
return Rule;
}(Lint.Rules.TypedRule));
exports.Rule = Rule;
var NoInferredEmptyObjectTypeRule = /** @class */ (function (_super) {
tslib_1.__extends(NoInferredEmptyObjectTypeRule, _super);
function NoInferredEmptyObjectTypeRule(sourceFile, ruleName, checker) {
var _this = _super.call(this, sourceFile, ruleName, undefined) || this;
_this.checker = checker;
return _this;
}
NoInferredEmptyObjectTypeRule.prototype.walk = function (sourceFile) {
var _this = this;
var cb = function (node) {
if (node.kind === ts.SyntaxKind.CallExpression) {
_this.checkCallExpression(node);
}
else if (node.kind === ts.SyntaxKind.NewExpression) {
_this.checkNewExpression(node);
}
return ts.forEachChild(node, cb);
};
return ts.forEachChild(sourceFile, cb);
};
NoInferredEmptyObjectTypeRule.prototype.checkNewExpression = function (node) {
var _this = this;
if (node.typeArguments === undefined) {
var type = this.checker.getTypeAtLocation(node);
if (tsutils_1.isTypeReference(type) &&
type.typeArguments !== undefined &&
type.typeArguments.some(function (a) { return tsutils_1.isObjectType(a) && _this.isEmptyObjectInterface(a); })) {
this.addFailureAtNode(node, Rule.EMPTY_INTERFACE_INSTANCE);
}
}
};
NoInferredEmptyObjectTypeRule.prototype.checkCallExpression = function (node) {
if (node.typeArguments !== undefined) {
return;
}
var callSig = this.checker.getResolvedSignature(node);
if (callSig === undefined) {
return;
}
var retType = this.checker.getReturnTypeOfSignature(callSig);
if (tsutils_1.isObjectType(retType) && this.isEmptyObjectInterface(retType)) {
this.addFailureAtNode(node, Rule.EMPTY_INTERFACE_FUNCTION);
}
};
NoInferredEmptyObjectTypeRule.prototype.isEmptyObjectInterface = function (objType) {
var _this = this;
return (tsutils_1.isObjectFlagSet(objType, ts.ObjectFlags.Anonymous) &&
objType.getProperties().length === 0 &&
objType.getNumberIndexType() === undefined &&
objType.getStringIndexType() === undefined &&
objType.getCallSignatures().every(function (signature) {
var type = _this.checker.getReturnTypeOfSignature(signature);
return tsutils_1.isObjectType(type) && _this.isEmptyObjectInterface(type);
}));
};
return NoInferredEmptyObjectTypeRule;
}(Lint.AbstractWalker));
var templateObject_1;