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"use strict";
/**
* @license
* Copyright 2019 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.applyWithFunction(sourceFile, walk, undefined, program.getTypeChecker());
};
/* tslint:disable:object-literal-sort-keys */
Rule.metadata = {
ruleName: "no-null-undefined-union",
description: Lint.Utils.dedent(templateObject_1 || (templateObject_1 = tslib_1.__makeTemplateObject(["\n Disallows explicitly declared or implicitly returned union types with both `null` and\n `undefined` as members.\n "], ["\n Disallows explicitly declared or implicitly returned union types with both \\`null\\` and\n \\`undefined\\` as members.\n "]))),
rationale: Lint.Utils.dedent(templateObject_2 || (templateObject_2 = tslib_1.__makeTemplateObject(["\n A union type that includes both `null` and `undefined` is either redundant or fragile.\n Enforcing the choice between the two allows the `triple-equals` rule to exist without\n exceptions, and is essentially a more flexible version of the `no-null-keyword` rule.\n Optional parameters are not considered to have the type `undefined`.\n "], ["\n A union type that includes both \\`null\\` and \\`undefined\\` is either redundant or fragile.\n Enforcing the choice between the two allows the \\`triple-equals\\` rule to exist without\n exceptions, and is essentially a more flexible version of the \\`no-null-keyword\\` rule.\n Optional parameters are not considered to have the type \\`undefined\\`.\n "]))),
optionsDescription: "Not configurable.",
options: null,
optionExamples: [true],
type: "functionality",
typescriptOnly: true,
requiresTypeInfo: true,
};
/* tslint:enable:object-literal-sort-keys */
Rule.FAILURE_STRING = "Union type cannot include both 'null' and 'undefined'.";
return Rule;
}(Lint.Rules.TypedRule));
exports.Rule = Rule;
function walk(ctx, tc) {
return ts.forEachChild(ctx.sourceFile, function cb(node) {
var type = getType(node, tc);
if (type !== undefined && isNullUndefinedUnion(type)) {
ctx.addFailureAtNode(node, Rule.FAILURE_STRING);
}
return ts.forEachChild(node, cb);
});
}
function getType(node, tc) {
if (tsutils_1.isUnionTypeNode(node)) {
return tc.getTypeAtLocation(node);
}
else if (tsutils_1.isSignatureDeclaration(node) && node.type === undefined) {
// Explicit types should be handled by the first case.
var signature = tc.getSignatureFromDeclaration(node);
return signature === undefined ? undefined : signature.getReturnType();
}
else {
return undefined;
}
}
function isNullUndefinedUnion(type) {
if (tsutils_1.isTypeReference(type) && type.typeArguments !== undefined) {
return type.typeArguments.some(isNullUndefinedUnion);
}
if (tsutils_1.isUnionType(type)) {
var hasNull = false;
var hasUndefined = false;
for (var _i = 0, _a = type.types; _i < _a.length; _i++) {
var subType = _a[_i];
hasNull = hasNull || subType.getFlags() === ts.TypeFlags.Null;
hasUndefined = hasUndefined || subType.getFlags() === ts.TypeFlags.Undefined;
if (hasNull && hasUndefined) {
return true;
}
}
}
return false;
}
var templateObject_1, templateObject_2;