@bit-ui-libs/common/src/lib/common/utils/get-error-message.ts

This library was generated with [Nx](https://nx.dev).

import axios from 'axios';
import { ApiServiceError } from '../../api/interfaces/api-service-error';

/**
 * This is a no-man's land function that tries
 * to handle every possible error scenario from ChainIT frontend & backend.
 * Handles simple error messages, axios errors, and now FATAL server error objects
 */
export function getErrorMessage(err: unknown) {
  if (!err) return '';

  // First, check if the error is an Axios error
  if (axios.isAxiosError(err) || (err as any)?.response) {
    const axiosError = err as ApiServiceError;
    // If response.data.message is not available then check for message
    const message = axiosError.response?.data?.message;

    // Backend returns an error message
    if (typeof message === 'string') {
      return message;
    }
    // Backend returns a really bad internal server error object
    // (e.g. { query: "UPDATE ...", parameters: [...], driverError: {...} })
    else if (typeof message === 'object') {
      // Usually, backend returns message as string array with the errors... usually.
      if (Array.isArray(message) && (message as any[]).every(m => typeof m === 'string')) {
        return (message as string[]).join(', ');
      }
      let fatalErrorMessage = JSON.stringify(message);
      // If the message comes as an object,
      // there is usually error details in a neighboring "error" property.
      const details = (axiosError.response?.data as any)?.error;
      // Prepend to fatal error object
      if (details) fatalErrorMessage = details + fatalErrorMessage;
      // Returns the error details + fatal error object
      return fatalErrorMessage;
    }
    // If none of the above work try accessing first-level message
    else if (axiosError.message) {
      return axiosError.message;
    }

    // This error isn't an axios error,
    // start checking for other properties below.
  }

  // Second, check if the error is an RTK error
  if (err && typeof err === 'object' && 'status' in err && 'data' in err) {
    if (Object.prototype.hasOwnProperty.call(err.data, 'message')) {
      return (err.data as { message: string }).message;
    }
  }

  // Next, check if the error is of type Error
  if (err instanceof Error) {
    const error = err as Error;
    return error.message;
  }

  // Next, check if the error has a property called message
  // (it can have message but not be of type Error (e.g. Geolocation error))
  if (Object.prototype.hasOwnProperty.call(err, 'message')) {
    return (err as { message: string }).message;
  }

  // Next, check if the error is just a string
  if (typeof err === 'string') {
    return err;
  }

  // Last resort, return a hardcoded unknown error message
  return 'Unknown error';
}