🎨 Enhance errorType and allow disabling it

Author: elbywan

src/config.ts

@@ -1,5 +1,5 @@
 import { mix } from "./utils.js"
-import type { Config } from "./types.js"
+import type { Config, ErrorType } from "./types.js"
 
 declare const global
 
@@ -94,7 +94,7 @@ export function setPolyfills(polyfills: object, replace = false) {
  *
  * If null, defaults to "text".
  */
-export function setErrorType(errorType: string) {
+export function setErrorType(errorType: ErrorType) {
   config.errorType = errorType
 }
 

src/core.ts

@@ -2,7 +2,7 @@ import { mix, extractContentType, isLikelyJsonMime } from "./utils.js"
 import { JSON_MIME, CONTENT_TYPE_HEADER, CATCHER_FALLBACK } from "./constants.js"
 import { resolver } from "./resolver.js"
 import config from "./config.js"
-import type { Wretch } from "./types.js"
+import type { Wretch, ErrorType } from "./types.js"
 
 export const core: Wretch = {
   _url: "",
@@ -16,7 +16,7 @@ export const core: Wretch = {
   addon(addon) {
     return { ...this, _addons: [...this._addons, addon], ...addon.wretch }
   },
-  errorType(errorType: string) {
+  errorType(errorType: ErrorType) {
     return {
       ...this,
       _config: {

src/resolver.ts

@@ -56,17 +56,29 @@ export const resolver = <T, Chain, R>(wretch: T & Wretch<T, Chain, R>) => {
         err["cause"] = referenceError
         err.stack = err.stack + "\nCAUSE: " + referenceError.stack
         err.response = response
+        err.status = response.status
         err.url = finalUrl
+
         if (response.type === "opaque") {
           throw err
         }
-        return response.text().then((body: string) => {
-          err.message = body
-          if (config.errorType === "json" || response.headers.get("Content-Type")?.split(";")[0] === "application/json") {
-            try { err.json = JSON.parse(body) } catch (e) { /* ignore */ }
+
+        const jsonErrorType = config.errorType === "json" || response.headers.get("Content-Type")?.split(";")[0] === "application/json"
+        const bodyPromise =
+          !config.errorType ? Promise.resolve(response.body) :
+            jsonErrorType ? response.text() :
+              response[config.errorType]()
+
+        return bodyPromise.then((body: unknown) => {
+          err.message = typeof body === "string" ? body : response.statusText
+          if(body) {
+            if(jsonErrorType && typeof body === "string") {
+              err.text = body
+              err.json = JSON.parse(body)
+            } else {
+              err[config.errorType] = body
+            }
           }
-          err.text = body
-          err["status"] = response.status
           throw err
         })
       }

src/types.ts

@@ -83,7 +83,7 @@ export interface Wretch<Self = unknown, Chain = unknown, Resolver = undefined> {
    * @category Helpers
    * @param method - The method to call on the Fetch response to read the body and use it as the Error message
    */
-  errorType(this: Self & Wretch<Self, Chain, Resolver>, method: string): this
+  errorType(this: Self & Wretch<Self, Chain, Resolver>, method: ErrorType): this
 
   /**
    * Sets non-global polyfills - for instance in browserless environments.
@@ -733,12 +733,14 @@ export interface WretchResponseChain<T, Self = unknown, R = undefined> {
   fetchError: (this: Self & WretchResponseChain<T, Self, R>, cb: WretchErrorCallback<T, Self, R>) => this,
 }
 
+export type ErrorType = "text" | "json" | "blob" | "formData" | "arrayBuffer" | undefined | null
+
 /**
  * Configuration object.
  */
 export type Config = {
   options: object;
-  errorType: string;
+  errorType: ErrorType;
   polyfills: object;
   polyfill(p: "fetch", doThrow?: boolean): typeof fetch;
   polyfill(p: "FormData", doThrow: boolean, instance: true, ...args: ConstructorParameters<typeof FormData>): FormData;

test/node/wretch.spec.ts

@@ -575,6 +575,16 @@ describe("Wretch", function () {
       })
       .res(_ => fail("I should never be called because an error was thrown"))
       .then(_ => expect(_).toBe(undefined))
+    // Disabled
+    await wretch(`${_URL}/json500raw`)
+      .errorType(null)
+      .get()
+      .internalError(error => {
+        expect(error.json).toEqual(undefined)
+        expect(error.text).toEqual(undefined)
+      })
+      .res(_ => fail("I should never be called because an error was thrown"))
+      .then(_ => expect(_).toBe(undefined))
     // Global
     wretch.errorType("json")
     await wretch(`${_URL}/json500raw`)