@service/error

@service/error provides two shared error classes, which allow error classes to be extended and inheritance checks to be perfomed.

Useful links & documentation

• service.js Github repository
• service.js website
• Learn service.js (tutorials + examples)
• service.js documentation
• Documentation for this package (@service/error)
• Commercial support
• Automorph (the company behind service.js)

Installation

If you're using Yarn:

yarn add @service/error

If you're using the npm command directly:

npm install @service/error

Usage

This package exports the classes DynamicError and ExtendableError.

ExtendableError (from the ts-error package) is a base error class that can be extended to achieve custom error classes with a working inheritance hierarchy, supporting all browsers (including very old versions) and of course node.

DynamicError (from the dynamic-error package) extends ExtendableError and can(re-)compute its message and stack trace dynamically when its state changes. It is useful for error messages that dynamically depend on props passed in the error constructor.

import { DynamicError, ExtendableError } from "@service/error

class MyExtendableError extends ExtendableError {
    constructor() {
      super("An optional error message");
    }
}

class MyDynamicError<T> extends DynamicError {
    protected someVar: T;
  
    constructor(someVar: T) {
        super(() => {
            this.someVar = someVar;
        });
    }

    public errorMessage() {
        return `Some error message depending on properties of this object, like someVar${this.someVar}`;
    }
}

try {
    throw new MyDynamicError(42);
} catch (e) {
    if (e instanceof DynamicError) {
      console.error("A DynamicError has been caught", e);
    }
    if (e instanceof ExtendableError) {
      console.error("An ExtendableError has been caught. In this example both lines will thus get printed");
    }
}

License: MIT

For the full license text, see ./LICENSE.