🏭 Add request parameter to .customError transformer

The customError transformer now receives the wretch request instance as a third parameter, allowing error handlers to access the original request context when transforming errors.

Author: elbywan

MIGRATION_V2_V3.md

@@ -121,7 +121,7 @@ interface ApiError {
 }
 
 const api = wretch("http://server")
-  .customError<ApiError>(async (error, response) => {
+  .customError<ApiError>(async (error, response, request) => {
     return { ...error, json: await response.json() }
   })
 

RECIPES.md

@@ -55,7 +55,7 @@ interface ApiError {
 }
 
 const api = wretch('https://jsonplaceholder.typicode.com')
-  .customError(async (error, response) => {
+  .customError(async (error, response, request) => {
     const body = await response.json().catch(() => ({ message: 'Unknown error' }));
     return { ...error, apiError: body as ApiError };
   });
@@ -78,7 +78,7 @@ try {
 import wretch from 'wretch';
 
 const api = wretch('https://jsonplaceholder.typicode.com')
-  .customError(async (error, response) => {
+  .customError(async (error, response, request) => {
     const contentType = response.headers.get('content-type') || '';
     let errorBody;
 

src/resolver.ts

@@ -79,7 +79,7 @@ export const resolver = <T, Chain, R, E>(wretch: T & Wretch<T, Chain, R, E>) =>
         catchers.get(CATCHER_FALLBACK)
 
       if(error.response && errorTransformer) {
-        error = await errorTransformer(error, error.response)
+        error = await errorTransformer(error, error.response, wretch)
       }
 
       if (catcher)

src/types.ts

@@ -26,7 +26,7 @@ export interface Wretch<Self = unknown, Chain = unknown, Resolver = undefined, E
   /**
    * @private @internal
    */
-  _errorTransformer?: <T>(error: WretchError, response: WretchResponse) => Promise<T> | T,
+  _errorTransformer?: <T>(error: WretchError, response: WretchResponse, request: Wretch<any, any, any, any>) => Promise<T> | T,
   /**
    * @private @internal
    */
@@ -311,7 +311,7 @@ export interface Wretch<Self = unknown, Chain = unknown, Resolver = undefined, E
    * }
    *
    * const api = wretch("https://api.example.com")
-   *   .customError<ApiError>(async (error, response) => {
+   *   .customError<ApiError>(async (error, response, request) => {
    *     const json = await response.json();
    *     return { ...error, ...json };
    *   });
@@ -326,9 +326,9 @@ export interface Wretch<Self = unknown, Chain = unknown, Resolver = undefined, E
    * ```
    *
    * @category Helpers
-   * @param transformer - A function that receives the error and response, and returns the transformed error with custom properties
+   * @param transformer - A function that receives the error, response, and request, and returns the transformed error with custom properties
    */
-  customError<T extends (ErrorType extends undefined ? any : ErrorType)>(this: Self & Wretch<Self, Chain, Resolver, ErrorType>, transformer: (error: WretchError, response: WretchResponse) => Promise<T> | T): Self & Wretch<Self, Chain, Resolver, T>
+  customError<T extends (ErrorType extends undefined ? any : ErrorType)>(this: Self & Wretch<Self, Chain, Resolver, ErrorType>, transformer: (error: WretchError, response: WretchResponse, request: Self & Wretch<Self, Chain, Resolver, ErrorType>) => Promise<T> | T): Self & Wretch<Self, Chain, Resolver, T>
 
   /**
    * Defer one or multiple request chain methods that will get called just before the request is sent.