Allow GrpcWebFetchTransport to use a custom fetch function

timostamm · Aug 10, 2023 · c308a30 · c308a30
1 parent 3a7ce47
commit c308a30
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Showing 3 changed files with 158 additions and 2 deletions.
diff --git a/packages/grpcweb-transport/spec/grpc-web-transport.spec.ts b/packages/grpcweb-transport/spec/grpc-web-transport.spec.ts
@@ -174,6 +174,72 @@ describe('GrpcWebFetchTransport', () => {
             globalThis.fetch = fetch;
         });
 
+        describe('with custom fetch() function', () => {
+            describe('in the call options', () => {
+                it('calls the custom fetch function instead of globalThis.fetch()', async () => {
+                    const optFetch = jasmine.createSpy('optFetch', (((...args: any[]): any => Promise.resolve() as any) as typeof originalFetch));
+                    const { next, body } = makeWhatWgStream();
+                    const res = getResponse({ body });
+                    const ret = new Deferred<typeof res>(true);
+                    fetch.and.returnValue(ret.promise);
+                    optFetch.and.returnValue(ret.promise);
+                    const call = transport.unary(methodInfo, callInput, { ...callOptions, fetch: optFetch });
+
+                    // Attach promise handlers
+                    const spy = {
+                        headers: jasmine.createSpy('call.headers'),
+                        response: jasmine.createSpy('call.response'),
+                        status: jasmine.createSpy('call.status'),
+                        trailers: jasmine.createSpy('call.trailers'),
+                    };
+
+                    for (let k in spy) {
+                        // @ts-ignore
+                        call[k].then(spy[k]);
+                    }
+
+                    const callPromiseSpy = jasmine.createSpy('call.then');
+                    call.then(callPromiseSpy);
+
+                    // custom fetch called with expected parameters
+                    expect(fetch).toHaveBeenCalledTimes(0);
+                    expect(optFetch).toHaveBeenCalledTimes(1);
+                });
+            });
+            describe('in the GrpcWebFetchTransport constructor options', () => {
+                it('calls the custom fetch function instead of globalThis.fetch()', async () => {
+                    const optFetch = jasmine.createSpy('optFetch', (((...args: any[]): any => Promise.resolve() as any) as typeof originalFetch));
+                    const transport = new GrpcWebFetchTransport({...base, fetch: optFetch});
+                    const { next, body } = makeWhatWgStream();
+                    const res = getResponse({ body });
+                    const ret = new Deferred<typeof res>(true);
+                    fetch.and.returnValue(ret.promise);
+                    optFetch.and.returnValue(ret.promise);
+                    const call = transport.unary(methodInfo, callInput, transport.mergeOptions(callOptions));
+
+                    // Attach promise handlers
+                    const spy = {
+                        headers: jasmine.createSpy('call.headers'),
+                        response: jasmine.createSpy('call.response'),
+                        status: jasmine.createSpy('call.status'),
+                        trailers: jasmine.createSpy('call.trailers'),
+                    };
+
+                    for (let k in spy) {
+                        // @ts-ignore
+                        call[k].then(spy[k]);
+                    }
+
+                    const callPromiseSpy = jasmine.createSpy('call.then');
+                    call.then(callPromiseSpy);
+
+                    // custom fetch called with expected parameters
+                    expect(fetch).toHaveBeenCalledTimes(0);
+                    expect(optFetch).toHaveBeenCalledTimes(1);
+                });
+            });
+        });
+
         it('handles a successful response', async () => {
             const { next, body } = makeWhatWgStream();
             const res = getResponse({ body });
@@ -459,6 +525,90 @@ describe('GrpcWebFetchTransport', () => {
             globalThis.fetch = fetch;
         });
 
+        describe('with custom fetch() function', () => {
+            describe('in the call options', () => {
+                it('calls the custom fetch function instead of globalThis.fetch()', async () => {
+                    const optFetch = jasmine.createSpy('optFetch', (((...args: any[]): any => Promise.resolve() as any) as typeof originalFetch));
+                    const { next, body } = makeWhatWgStream();
+                    const res = getResponse({ body });
+                    const ret = new Deferred<typeof res>(true);
+                    fetch.and.returnValue(ret.promise);
+                    optFetch.and.returnValue(ret.promise);
+                    const call = transport.serverStreaming(methodInfo, callInput, { ...callOptions, fetch: optFetch });
+
+                    const responseIterator = call.responses[Symbol.asyncIterator]();
+
+                    // Attach promise handlers
+                    const spy = {
+                        headers: jasmine.createSpy('call.headers'),
+                        status: jasmine.createSpy('call.status'),
+                        trailers: jasmine.createSpy('call.trailers'),
+                    };
+
+                    for (let k in spy) {
+                        // @ts-ignore
+                        call[k].then(spy[k]);
+                    }
+
+                    const responsesIteratorSpy = jasmine.createSpy<(res: IteratorResult<ResponseMessage>) => void>('call.responses.iterator');
+
+                    let nextIteratorResult = responseIterator.next().then(function chunkThen(res) {
+                        responsesIteratorSpy(res);
+                        nextIteratorResult = responseIterator.next().then(chunkThen);
+                        return res;
+                    });
+
+                    const callPromiseSpy = jasmine.createSpy('call.then');
+                    call.then(callPromiseSpy);
+
+                    // Fetch called with expected parameters
+                    expect(fetch).toHaveBeenCalledTimes(0);
+                    expect(optFetch).toHaveBeenCalledTimes(1);
+                });
+            });
+            describe('in the GrpcWebFetchTransport constructor options', () => {
+                it('calls the custom fetch function instead of globalThis.fetch()', async () => {
+                    const optFetch = jasmine.createSpy('optFetch', (((...args: any[]): any => Promise.resolve() as any) as typeof originalFetch));
+                    const transport = new GrpcWebFetchTransport({...base, fetch: optFetch});
+                    const { next, body } = makeWhatWgStream();
+                    const res = getResponse({ body });
+                    const ret = new Deferred<typeof res>(true);
+                    fetch.and.returnValue(ret.promise);
+                    optFetch.and.returnValue(ret.promise);
+                    const call = transport.serverStreaming(methodInfo, callInput, transport.mergeOptions(callOptions));
+
+                    const responseIterator = call.responses[Symbol.asyncIterator]();
+
+                    // Attach promise handlers
+                    const spy = {
+                        headers: jasmine.createSpy('call.headers'),
+                        status: jasmine.createSpy('call.status'),
+                        trailers: jasmine.createSpy('call.trailers'),
+                    };
+
+                    for (let k in spy) {
+                        // @ts-ignore
+                        call[k].then(spy[k]);
+                    }
+
+                    const responsesIteratorSpy = jasmine.createSpy<(res: IteratorResult<ResponseMessage>) => void>('call.responses.iterator');
+
+                    let nextIteratorResult = responseIterator.next().then(function chunkThen(res) {
+                        responsesIteratorSpy(res);
+                        nextIteratorResult = responseIterator.next().then(chunkThen);
+                        return res;
+                    });
+
+                    const callPromiseSpy = jasmine.createSpy('call.then');
+                    call.then(callPromiseSpy);
+
+                    // Fetch called with expected parameters
+                    expect(fetch).toHaveBeenCalledTimes(0);
+                    expect(optFetch).toHaveBeenCalledTimes(1);
+                });
+            });
+        });
+
         it('handles a successful serverStreaming call', async () => {
             const { next, body } = makeWhatWgStream();
             const res = getResponse({ body });

diff --git a/packages/grpcweb-transport/src/grpc-web-options.ts b/packages/grpcweb-transport/src/grpc-web-options.ts
@@ -33,4 +33,8 @@ export interface GrpcWebOptions extends RpcOptions {
      */
 	fetchInit?: Omit<RequestInit, 'body' | 'headers' | 'method' | 'signal'>;
 
+    /**
+     * A `fetch` function to use in place of `globalThis.fetch`
+     */
+    fetch?: typeof fetch;
 }
diff --git a/packages/grpcweb-transport/src/grpc-web-transport.ts b/packages/grpcweb-transport/src/grpc-web-transport.ts
@@ -89,6 +89,7 @@ export class GrpcWebFetchTransport implements RpcTransport {
         let
             opt = options as GrpcWebOptions,
             format = opt.format ?? 'text',
+            fetch = opt.fetch ?? globalThis.fetch,
             fetchInit = opt.fetchInit ?? {},
             url = this.makeUrl(method, opt),
             inputBytes = method.I.toBinary(input, opt.binaryOptions),
@@ -100,7 +101,7 @@ export class GrpcWebFetchTransport implements RpcTransport {
             maybeTrailer: RpcMetadata | undefined,
             defTrailer = new Deferred<RpcMetadata>();
 
-        globalThis.fetch(url, {
+        fetch(url, {
             ...fetchInit,
             method: 'POST',
             headers: createGrpcWebRequestHeader(new globalThis.Headers(), format, opt.timeout, opt.meta),
@@ -197,6 +198,7 @@ export class GrpcWebFetchTransport implements RpcTransport {
         let
             opt = options as GrpcWebOptions,
             format = opt.format ?? 'text',
+            fetch = opt.fetch ?? globalThis.fetch,
             fetchInit = opt.fetchInit ?? {},
             url = this.makeUrl(method, opt),
             inputBytes = method.I.toBinary(input, opt.binaryOptions),
@@ -208,7 +210,7 @@ export class GrpcWebFetchTransport implements RpcTransport {
             maybeTrailer: RpcMetadata | undefined,
             defTrailer = new Deferred<RpcMetadata>();
 
-        globalThis.fetch(url, {
+        fetch(url, {
             ...fetchInit,
             method: 'POST',
             headers: createGrpcWebRequestHeader(new globalThis.Headers(), format, opt.timeout, opt.meta),