Function createCustomError

Create a Custom Error class which may be used to throw custom errors.

Example

import { createCustomError, isError } from "@nevware21/ts-utils";

// For an error that just contains a message
let myCustomErrorError = createCustomError("MessageError");

try {
    throw new myCustomErrorError("Error Message!");
} catch(e) {
     // e.name === MessageError
     // isError(e) === true;
     // Object.prototype.toString.call(e) === "[object Error]";
}

// Or a more complex error object
interface MyCriticalErrorConstructor extends CustomErrorConstructor {
    new(message: string, file: string, line: number, col: number): MyCriticalError;
    (message: string, file: string, line: number, col: number): MyCriticalError;
}

interface MyCriticalError extends Error {
    readonly errorId: number;
    readonly args: any[];        // Holds all of the arguments passed during construction
}

let _totalErrors = 0;
let myCustomError = createCustomError<MyCriticalErrorConstructor>("CriticalError", (self, args) => {
    _totalErrors++;
    self.errorId = _totalErrors;
    self.args = args;
});

try {
    throw new myCustomError("Not Again!");
} catch(e) {
     // e.name === CriticalError
     // isError(e) === true;
     // Object.prototype.toString.call(e) === "[object Error]";
}

// ----------------------------------------------------------
// Extending another custom error class
// ----------------------------------------------------------

let AppError = createCustomError("ApplicationError");
let theAppError = new appError();

isError(theAppError);                    // true
theAppError instanceof Error;            // true
theAppError instanceof AppError;         // true

let StartupError = createCustomError("StartupError", null, AppError);
let theStartupError = new StartupError();

isError(theStartupError);                // true
theStartupError instanceof Error;        // true
theStartupError instanceof AppError;     // true
theStartupError instanceof StartupError; // true
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