From 53ec6fc397e731859d99476265ddf1891d2a0522 Mon Sep 17 00:00:00 2001
From: LautaroPetaccio <lausuper@gmail.com>
Date: Wed, 24 Jun 2026 14:44:16 -0300
Subject: [PATCH] feat: accept the native fetch directly as the HTTPProvider
 fetch option
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FetchFunction declared `mode?: string`, which made the global native fetch
non-assignable to it (native `RequestInit` types `mode` as `RequestMode`, and
`string` is not assignable to `RequestMode`), forcing callers to cast with
`fetch as unknown as FetchFunction`. HTTPProvider never sets `mode`, so dropping
it lets the global native fetch — the same WHATWG signature on web and server —
as well as native-fetch components (e.g. @dcl/fetch-component) and node-fetch be
passed to `options.fetch` with no cast.

Type-only change: the emitted JS is unchanged, and existing callers (including
those still passing node-fetch) keep compiling. Adds compile-time assertions and
regenerates the API report and docs.
---
 docs/eth-connect.fetchfunction.md |  1 -
 report/eth-connect.api.md         |  1 -
 src/providers/HTTPProvider.ts     |  6 +++++-
 test/HTTPProvider.spec.ts         | 24 +++++++++++++++++++++++-
 4 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/docs/eth-connect.fetchfunction.md b/docs/eth-connect.fetchfunction.md
index b4c43e44..83045df9 100644
--- a/docs/eth-connect.fetchfunction.md
+++ b/docs/eth-connect.fetchfunction.md
@@ -10,7 +10,6 @@
 export type FetchFunction = (url: string, params: {
     body?: any;
     method?: string;
-    mode?: string;
     headers?: any;
 }) => Promise<any>;
 ```
diff --git a/report/eth-connect.api.md b/report/eth-connect.api.md
index eb06a378..6c1a9b4e 100644
--- a/report/eth-connect.api.md
+++ b/report/eth-connect.api.md
@@ -880,7 +880,6 @@ export function extractTypeName(name: string): string;
 export type FetchFunction = (url: string, params: {
     body?: any;
     method?: string;
-    mode?: string;
     headers?: any;
 }) => Promise<any>;
 
diff --git a/src/providers/HTTPProvider.ts b/src/providers/HTTPProvider.ts
index 3472f1cf..dcf10662 100644
--- a/src/providers/HTTPProvider.ts
+++ b/src/providers/HTTPProvider.ts
@@ -1,12 +1,16 @@
 import { RPCMessage, Callback, toRPC } from './common'
 export { RPCMessage, Callback } from './common'
 
+// Structurally compatible with the global native `fetch` (the same WHATWG signature on web
+// and server) as well as native-fetch components (e.g. @dcl/fetch-component) and node-fetch,
+// so callers can pass any of them directly without a cast. Only the fields HTTPProvider sets
+// are listed; a previous `mode?: string` was dropped because it is unused here and made the
+// native fetch's `RequestInit` (`mode?: RequestMode`) non-assignable to this type.
 export type FetchFunction = (
   url: string,
   params: {
     body?: any
     method?: string
-    mode?: string
     headers?: any
   }
 ) => Promise<any>
diff --git a/test/HTTPProvider.spec.ts b/test/HTTPProvider.spec.ts
index e5cf52b0..4215bac2 100644
--- a/test/HTTPProvider.spec.ts
+++ b/test/HTTPProvider.spec.ts
@@ -1,4 +1,4 @@
-import { HTTPProvider } from '../src/providers/HTTPProvider'
+import { HTTPProvider, HTTPProviderOptions } from '../src/providers/HTTPProvider'
 
 type SendResult = { err: Error | null; result: any }
 
@@ -110,3 +110,25 @@ describe('when sending an async request through the HTTPProvider', () => {
     })
   })
 })
+
+describe('when configuring the fetch option', () => {
+  describe('and the global native fetch is supplied', () => {
+    it('should be accepted without a cast', () => {
+      // This compiles only if the global native fetch (same WHATWG signature on web and
+      // server) is assignable to the fetch option — the point of this change.
+      const options: HTTPProviderOptions = { fetch: globalThis.fetch }
+
+      expect(typeof options.fetch).toBe('function')
+    })
+  })
+
+  describe('and a native-fetch component is supplied', () => {
+    it('should be accepted without a cast', () => {
+      // Mirrors the shape of native-fetch components such as @dcl/fetch-component.
+      const fetchComponent: (url: string, init?: RequestInit) => Promise<Response> = globalThis.fetch
+      const options: HTTPProviderOptions = { fetch: fetchComponent }
+
+      expect(typeof options.fetch).toBe('function')
+    })
+  })
+})