Fix outgoing messages for rust-crypto (matrix-org#3025)

It turns out that MatrixClient uses a `FetchHttpApi` instance with
`opts.onlyData = true`, so it was returning the json-parsed response rather
than the raw response. Change the way we call `authedRequest` so that we get
the raw body back.

Author: richvdh

spec/unit/rust-crypto.spec.ts

@@ -30,7 +30,7 @@ import MockHttpBackend from "matrix-mock-request";
 
 import { RustCrypto } from "../../src/rust-crypto/rust-crypto";
 import { initRustCrypto } from "../../src/rust-crypto";
-import { HttpApiEvent, HttpApiEventHandlerMap, IHttpOpts, IToDeviceEvent, MatrixHttpApi } from "../../src";
+import { HttpApiEvent, HttpApiEventHandlerMap, IToDeviceEvent, MatrixClient, MatrixHttpApi } from "../../src";
 import { TypedEventEmitter } from "../../src/models/typed-event-emitter";
 
 afterEach(() => {
@@ -48,7 +48,7 @@ describe("RustCrypto", () => {
         let rustCrypto: RustCrypto;
 
         beforeEach(async () => {
-            const mockHttpApi = {} as MatrixHttpApi<IHttpOpts>;
+            const mockHttpApi = {} as MatrixClient["http"];
             rustCrypto = (await initRustCrypto(mockHttpApi, TEST_USER, TEST_DEVICE_ID)) as RustCrypto;
         });
 
@@ -62,7 +62,7 @@ describe("RustCrypto", () => {
         let rustCrypto: RustCrypto;
 
         beforeEach(async () => {
-            const mockHttpApi = {} as MatrixHttpApi<IHttpOpts>;
+            const mockHttpApi = {} as MatrixClient["http"];
             rustCrypto = (await initRustCrypto(mockHttpApi, TEST_USER, TEST_DEVICE_ID)) as RustCrypto;
         });
 
@@ -132,6 +132,7 @@ describe("RustCrypto", () => {
                 baseUrl: "https://example.com",
                 prefix: "/_matrix",
                 fetchFn: httpBackend.fetchFn as typeof global.fetch,
+                onlyData: true,
             });
 
             // for these tests we use a mock OlmMachine, with an implementation of outgoingRequests that

src/rust-crypto/index.ts

@@ -23,7 +23,7 @@ import { RUST_SDK_STORE_PREFIX } from "./constants";
 import { IHttpOpts, MatrixHttpApi } from "../http-api";
 
 export async function initRustCrypto(
-    http: MatrixHttpApi<IHttpOpts>,
+    http: MatrixHttpApi<IHttpOpts & { onlyData: true }>,
     userId: string,
     deviceId: string,
 ): Promise<CryptoBackend> {

src/rust-crypto/rust-crypto.ts

@@ -28,7 +28,7 @@ import type { IToDeviceEvent } from "../sync-accumulator";
 import { MatrixEvent } from "../models/event";
 import { CryptoBackend, OnSyncCompletedData } from "../common-crypto/CryptoBackend";
 import { logger } from "../logger";
-import { IHttpOpts, IRequestOpts, MatrixHttpApi, Method } from "../http-api";
+import { IHttpOpts, MatrixHttpApi, Method } from "../http-api";
 import { QueryDict } from "../utils";
 
 /**
@@ -54,7 +54,7 @@ export class RustCrypto implements CryptoBackend {
 
     public constructor(
         private readonly olmMachine: RustSdkCryptoJs.OlmMachine,
-        private readonly http: MatrixHttpApi<IHttpOpts>,
+        private readonly http: MatrixHttpApi<IHttpOpts & { onlyData: true }>,
         _userId: string,
         _deviceId: string,
     ) {}
@@ -181,21 +181,21 @@ export class RustCrypto implements CryptoBackend {
         }
     }
 
-    private async rawJsonRequest(
-        method: Method,
-        path: string,
-        queryParams: QueryDict,
-        body: string,
-        opts: IRequestOpts = {},
-    ): Promise<string> {
-        // unbeknownst to HttpApi, we are sending JSON
-        if (!opts.headers) opts.headers = {};
-        opts.headers["Content-Type"] = "application/json";
-
-        // we use the full prefix
-        if (!opts.prefix) opts.prefix = "";
-
-        const resp = await this.http.authedRequest(method, path, queryParams, body, opts);
-        return await resp.text();
+    private async rawJsonRequest(method: Method, path: string, queryParams: QueryDict, body: string): Promise<string> {
+        const opts = {
+            // inhibit the JSON stringification and parsing within HttpApi.
+            json: false,
+
+            // nevertheless, we are sending, and accept, JSON.
+            headers: {
+                "Content-Type": "application/json",
+                "Accept": "application/json",
+            },
+
+            // we use the full prefix
+            prefix: "",
+        };
+
+        return await this.http.authedRequest<string>(method, path, queryParams, body, opts);
     }
 }