extract-problem-details v1.0.2

Extract Problem Details

A lightweight library that extracts the problem details (RFC 7807) object from an unsuccessful response. Easily maps a typed Problem Details object to be used for handling unsuccessful responses from an API that implements the Problem Details web specification RFC 7807.

Response objects may lack problem details properties or have none at all, in which case they default to a problem details object with status: 500 and title: "Server Error".

Usage

Install npm package

npm i extract-problem-details

Import getProblemDetails and ProblemDetails type

import getProblemDetails from "extract-problem-details";
import type {ProblemDetails} from "extract-problem-details";

Examples

Extracting as many Problem Details properties from a failed response

After parsing a response, call the getProblemDetails function and pass the parsed response to getProblemDetails to obtain a ProblemDetails object. You can then log this object or display the failed response to the user.

if (!response.ok) {
    const responseResult = await response.json() as unknown;
    
    /************************************************************************/
    const problemDetails: ProblemDetails = getProblemDetails(responseResult);
    /************************************************************************/
    
    // Do something with your problem details object, 
    // such as making a toast for your users to display a failed response.
    problemToast(problemDetails);   // Custom toast not provided.
}

Getting a Problem Details object from a produced exception while fetching

let response: Response | undefined;
try {
    // Your fetch logic...
} catch (e) {
    // Create your own getErrorMessage to extract error message or set a default error message.
    const errMsg = getErrorMessage(e);
    /*************************************************************************/
    const problemDetails: ProblemDetails = getProblemDetails(response, errMsg);
    /*************************************************************************/
    problemToast(problemDetails);   // Custom toast not provided.
}

Problem Details Object

interface ProblemDetails {
    type?: string;
    title: string;
    status: number;
    detail?: string;
    traceId?: string;
    instance?: string;
    // Default problem details extention in ASP.NET
    errors?: Record<string, string[]>
}

TODO

• Add functionality for custom problem details extensions to replace errors.