feat: add before and after request methods to base service (#961)

* testing with simple.ts

* what we want it to look like

* working

* passes tests

* docs: document new feature

* correctly call using req/res instead of metadata

* fix typing

README.markdown

@@ -446,6 +446,10 @@ Generated code will be placed in the Gradle build directory.
 
 - With `--ts_proto_opt=outputServices=false`, or `=none`, ts-proto will output NO service definitions.
 
+- With `--ts_proto_opt=outputBeforeRequest=true`, ts-proto will add a function definition to the Rpc interface definition with the signature: `beforeRequest(request: <RequestType>)`. It will will also automatically set `outputTypeRegistry=true` and `outputServices=true`. Each of the Service's methods will call `beforeRequest` before performing it's request.
+
+- With `--ts_proto_opt=outputAfterResponse=true`, ts-proto will add a function definition to the Rpc interface definition with the signature: `afterResponse(response: <ResponseType>)`. It will will also automatically set `outputTypeRegistry=true` and `outputServices=true`. Each of the Service's methods will call `afterResponse` before returning the response.
+
 - With `--ts_proto_opt=useAbortSignal=true`, the generated services will accept an `AbortSignal` to cancel RPC calls.
 
 - With `--ts_proto_opt=useAsyncIterable=true`, the generated services will use `AsyncIterable` instead of `Observable`.

integration/before-after-request/before-after-request-test.ts

@@ -0,0 +1,47 @@
+import { FooServiceClientImpl, FooServiceCreateRequest, FooServiceCreateResponse } from "./simple";
+import { MessageType } from "./typeRegistry";
+
+interface Rpc {
+  request(service: string, method: string, data: Uint8Array): Promise<Uint8Array>;
+  beforeRequest?<T extends { [k in keyof T]: unknown }>(request: T): void;
+  afterResponse?<T extends { [k in keyof T]: unknown }>(response: T): void;
+}
+
+describe("before-after-request", () => {
+  const exampleData = {
+    kind: 1,
+  };
+  let rpc = {
+    request: jest.fn(() => Promise.resolve(new Uint8Array())),
+  };
+  let client = new FooServiceClientImpl(rpc);
+  const beforeRequest = jest.fn();
+  const afterResponse = jest.fn();
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+    jest.spyOn(FooServiceCreateResponse, "decode").mockReturnValue(exampleData);
+  });
+
+  it("performs function before request if specified", async () => {
+    const req = FooServiceCreateRequest.create(exampleData);
+    client = new FooServiceClientImpl({ ...rpc, beforeRequest: beforeRequest });
+    await client.Create(req);
+    expect(beforeRequest).toHaveBeenCalledWith(req);
+  });
+
+  it("performs function after request if specified", async () => {
+    const req = FooServiceCreateRequest.create(exampleData);
+    client = new FooServiceClientImpl({ ...rpc, afterResponse: afterResponse });
+    await client.Create(req);
+    expect(afterResponse).toHaveBeenCalledWith(exampleData);
+  });
+
+  it("doesn't perform function before or after request if they are not specified", async () => {
+    const req = FooServiceCreateRequest.create(exampleData);
+    client = new FooServiceClientImpl({ ...rpc });
+    await client.Create(req);
+    expect(beforeRequest).not.toHaveBeenCalled();
+    expect(afterResponse).not.toHaveBeenCalled();
+  });
+});

integration/before-after-request/parameters.txt

@@ -0,0 +1 @@
+outputBeforeRequest=true,outputAfterResponse=true

integration/before-after-request/simple.proto

@@ -0,0 +1,37 @@
+syntax = "proto3";
+package simple;
+import "simple2.proto";
+
+enum SimpleEnum {
+  LOCAL_DEFAULT = 0;
+  LOCAL_FOO = 1;
+  LOCAL_BAR = 2;
+}
+
+message Simple {
+  string name = 1;
+  simple2.Simple otherSimple = 2;
+}
+
+message DifferentSimple {
+  string name = 1;
+  optional simple2.Simple otherOptionalSimple2 = 2;
+}
+
+message SimpleEnums {
+  SimpleEnum local_enum = 1;
+  simple2.SimpleEnum import_enum = 2;
+}
+
+message FooServiceCreateRequest {
+  simple2.FooService kind = 1;
+}
+
+message FooServiceCreateResponse {
+  simple2.FooService kind = 1;
+}
+
+service FooService {
+  rpc Create  (FooServiceCreateRequest) returns (FooServiceCreateResponse);
+}
+