js-draw/dist/cjs/util/assertions.js

Draw pictures using a pen, touchscreen, or mouse! JS-draw is a drawing library for JavaScript and TypeScript.

"use strict";
// Note: Arrow functions cannot be used for type assertions. See
// https://github.com/microsoft/TypeScript/issues/34523
Object.defineProperty(exports, "__esModule", { value: true });
exports.assertUnreachable = assertUnreachable;
exports.assertIsNumber = assertIsNumber;
exports.assertIsString = assertIsString;
exports.assertIsArray = assertIsArray;
exports.assertIsNumberArray = assertIsNumberArray;
exports.assertIsStringArray = assertIsStringArray;
exports.assertIsBoolean = assertIsBoolean;
exports.assertTruthy = assertTruthy;
exports.assertIsObject = assertIsObject;
/**
 * Compile-time assertion that a branch of code is unreachable.
 * @internal
 */
function assertUnreachable(key) {
    // See https://stackoverflow.com/a/39419171/17055750
    throw new Error(`Should be unreachable. Key: ${key}.`);
}
/**
 * Throws an exception if the typeof given value is not a number or `value` is NaN.
 *
 * @example
 * ```ts
 * const foo: unknown = 3;
 * assertIsNumber(foo);
 *
 * assertIsNumber('hello, world'); // throws an Error.
 * ```
 */
function assertIsNumber(value, allowNaN = false) {
    if (typeof value !== 'number' || (!allowNaN && isNaN(value))) {
        throw new Error('Given value is not a number');
    }
}
/** Throws an `Error` if the given `value` is not a `string`. */
function assertIsString(value) {
    if (typeof value !== 'string') {
        throw new Error('Given value is not a string');
    }
}
function assertIsArray(values) {
    if (!Array.isArray(values)) {
        throw new Error('Asserting isArray: Given entity is not an array');
    }
}
/**
 * Throws if any of `values` is not of type number.
 */
function assertIsNumberArray(values, allowNaN = false) {
    assertIsArray(values);
    assertIsNumber(values.length);
    for (const value of values) {
        assertIsNumber(value, allowNaN);
    }
}
/**
 * Throws if any of `values` is not of type `string`.
 */
function assertIsStringArray(values) {
    assertIsArray(values);
    assertIsNumber(values.length);
    for (const value of values) {
        assertIsString(value);
    }
}
/**
 * Throws an exception if `typeof value` is not a boolean.
 */
function assertIsBoolean(value) {
    if (typeof value !== 'boolean') {
        throw new Error('Given value is not a boolean');
    }
}
function assertTruthy(value) {
    if (!value) {
        throw new Error(`${JSON.stringify(value)} is not truthy`);
    }
}
function assertIsObject(value) {
    if (typeof value !== 'object') {
        throw new Error(`AssertIsObject: Given entity is not an object (type = ${typeof value})`);
    }
}