feat(types): allow Service<T> to handle non-WorkerEntrypoint default export

Author: edmundhung

src/workerd/api/http.h

@@ -436,7 +436,11 @@ class Fetcher: public JsRpcClientProvider {
       });
     }
     JSG_TS_DEFINE(
-      type Service<T extends Rpc.WorkerEntrypointBranded | undefined = undefined> = Fetcher<T>;
+      type Service<T = undefined> = Fetcher<
+          T extends new (...args: any[]) => infer EntrypointClass
+              ? EntrypointClass extends Rpc.WorkerEntrypointBranded ? EntrypointClass : undefined
+              : T extends Rpc.WorkerEntrypointBranded ? T : undefined
+      >;
     );
 
     if (!flags.getFetcherNoGetPutDelete()) {

types/generated-snapshot/experimental/index.d.ts

@@ -1761,8 +1761,15 @@ interface RequestInit<Cf = CfProperties> {
   signal?: AbortSignal | null;
   encodeResponseBody?: "automatic" | "manual";
 }
-type Service<T extends Rpc.WorkerEntrypointBranded | undefined = undefined> =
-  Fetcher<T>;
+type Service<T = undefined> = Fetcher<
+  T extends new (...args: any[]) => infer EntrypointClass
+    ? EntrypointClass extends Rpc.WorkerEntrypointBranded
+      ? EntrypointClass
+      : undefined
+    : T extends Rpc.WorkerEntrypointBranded
+      ? T
+      : undefined
+>;
 type Fetcher<
   T extends Rpc.EntrypointBranded | undefined = undefined,
   Reserved extends string = never,

types/generated-snapshot/experimental/index.ts

@@ -1769,9 +1769,15 @@ export interface RequestInit<Cf = CfProperties> {
   signal?: AbortSignal | null;
   encodeResponseBody?: "automatic" | "manual";
 }
-export type Service<
-  T extends Rpc.WorkerEntrypointBranded | undefined = undefined,
-> = Fetcher<T>;
+export type Service<T = undefined> = Fetcher<
+  T extends new (...args: any[]) => infer EntrypointClass
+    ? EntrypointClass extends Rpc.WorkerEntrypointBranded
+      ? EntrypointClass
+      : undefined
+    : T extends Rpc.WorkerEntrypointBranded
+      ? T
+      : undefined
+>;
 export type Fetcher<
   T extends Rpc.EntrypointBranded | undefined = undefined,
   Reserved extends string = never,

types/generated-snapshot/latest/index.d.ts

@@ -1727,8 +1727,15 @@ interface RequestInit<Cf = CfProperties> {
   signal?: AbortSignal | null;
   encodeResponseBody?: "automatic" | "manual";
 }
-type Service<T extends Rpc.WorkerEntrypointBranded | undefined = undefined> =
-  Fetcher<T>;
+type Service<T = undefined> = Fetcher<
+  T extends new (...args: any[]) => infer EntrypointClass
+    ? EntrypointClass extends Rpc.WorkerEntrypointBranded
+      ? EntrypointClass
+      : undefined
+    : T extends Rpc.WorkerEntrypointBranded
+      ? T
+      : undefined
+>;
 type Fetcher<
   T extends Rpc.EntrypointBranded | undefined = undefined,
   Reserved extends string = never,

types/generated-snapshot/latest/index.ts

@@ -1735,9 +1735,15 @@ export interface RequestInit<Cf = CfProperties> {
   signal?: AbortSignal | null;
   encodeResponseBody?: "automatic" | "manual";
 }
-export type Service<
-  T extends Rpc.WorkerEntrypointBranded | undefined = undefined,
-> = Fetcher<T>;
+export type Service<T = undefined> = Fetcher<
+  T extends new (...args: any[]) => infer EntrypointClass
+    ? EntrypointClass extends Rpc.WorkerEntrypointBranded
+      ? EntrypointClass
+      : undefined
+    : T extends Rpc.WorkerEntrypointBranded
+      ? T
+      : undefined
+>;
 export type Fetcher<
   T extends Rpc.EntrypointBranded | undefined = undefined,
   Reserved extends string = never,