decodeRequestErrorMessage

The decodeRequestErrorMessage function is a utility for extracting meaningful error messages from HTTP response data. It intelligently checks multiple common error message locations and returns the first valid message found, or a default fallback message.

Import

import { decodeRequestErrorMessage } from "@arkyn/server";

Parameters

The function accepts the following parameters:

`data` (required)

The data object that may contain error information. This is typically the parsed JSON body from an error response.

Type: any

`response` (required)

The Web API Response object that may contain a statusText property representing the HTTP status text.

Type: Response

Usage example

The function returns a string representing the decoded error message.

Type: string

typescript

import { decodeRequestErrorMessage } from "@arkyn/server";

// Example with data.message
const data = { message: "User not found" };
const message1 = decodeRequestErrorMessage(data, response);
console.log(message1);
// Output: "User not found"

Extraction order

The function checks for error messages in the following order and returns the first valid string found:

data.message: Direct message property on the data
data.error: Error property as a string
data.error.message: Nested message inside an error object
response.statusText: HTTP status text from the Response object
Default: If none of the above are valid strings, returns "Missing error message"

Notes

This function is designed to handle the variety of error response formats commonly used by different APIs:

Express/Node.js APIs often use { message: "..." }
Some REST APIs use { error: "..." }
Structured error responses often use { error: { message: "..." } }

The function performs type checking to ensure each property is a string before returning it, preventing unexpected object or array values from being returned.

If all checks fail, the function returns the default message "Missing error message" to ensure a consistent return type.

Common use cases include error handling in API clients, displaying user-friendly error messages, and logging error responses.

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