1/* 2 * Copyright (C) 2023 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17export function assertDefined<A>(value: A | null | undefined): A { 18 if (value === undefined || value === null) { 19 throw new Error(`Expected value, but found '${value}'`); 20 } 21 return value; 22} 23 24export function assertTrue(value: boolean, lazyErrorMessage?: () => string) { 25 if (!value) { 26 throw new Error( 27 lazyErrorMessage ? lazyErrorMessage() : 'Expected value to be true', 28 ); 29 } 30} 31 32// Ensure at compile-time that a certain line is not reachable. 33// E.g. make sure that a switch/case handles all possible input values. 34export function assertUnreachable(x: never): never { 35 throw new Error('This line should never execute'); 36} 37