Add support for downloading authenticated content

src/MatrixClient.ts

@@ -1609,6 +1609,29 @@ export class MatrixClient extends EventEmitter {
             .then(response => response["content_uri"]);
     }
 
+    /**
+     * Download Authenticated content from the homeserver's media repository. Note that this will <b>not</b> automatically
+     * decrypt media as it cannot determine if the media is encrypted.
+     * @param {string} mxcUrl The MXC URI for the content.
+     * @param {number} timeoutMs The maximum number of milliseconds that the client is willing to wait to start receiving data,
+     * in the case that the content has not yet been uploaded. The default value is 20000 (20 seconds). 
+     * @returns {Promise<{data: Buffer, contentType: string}>} Resolves to the downloaded content.
+     */
+    public async downloadAuthenticatedContent(mxcUrl: string, timeoutMs = 20000): Promise<{ data: Buffer, contentType: string }> {
+        if (!mxcUrl.toLowerCase().startsWith("mxc://")) {
+            throw Error("'mxcUrl' does not begin with mxc://");
+        }
+        const urlParts = mxcUrl.substr("mxc://".length).split("/");
+        const domain = encodeURIComponent(urlParts[0]);
+        const mediaId = encodeURIComponent(urlParts[1].split("/")[0]);
+        const path = `/_matrix/client/v1/media/download/${domain}/${mediaId}`;
+        const res = await this.doRequest("GET", path, { timeout_ms: timeoutMs }, null, null, true, null, true);
+        return {
+            data: res.body,
+            contentType: res.headers["content-type"],
+        };
+    }
+
     /**
      * Download content from the homeserver's media repository. Note that this will <b>not</b> automatically decrypt
      * media as it cannot determine if the media is encrypted.

test/MatrixClientTest.ts

@@ -5727,6 +5727,35 @@ describe('MatrixClient', () => {
         });
     });
 
+    describe('downloadAuthenticatedContent', () => {
+        it('should call the right endpoint', async () => {
+            const { client, http } = createTestClient();
+            const urlPart = "example.org/testing";
+            const mxcUrl = "mxc://" + urlPart;
+            // const fileContents = Buffer.from("12345");
+
+            // noinspection TypeScriptValidateJSTypes
+            http.when("GET", "/_matrix/client/v1/media/download/").respond(200, (path, _, req) => {
+                expect(path).toContain("/_matrix/client/v1/media/download/" + urlPart);
+                expect((req as any).opts.encoding).toEqual(null);
+                // TODO: Honestly, I have no idea how to coerce the mock library to return headers or buffers,
+                // so this is left as a fun activity.
+                // return {
+                //     body: fileContents,
+                //     headers: {
+                //         "content-type": "test/test",
+                //     },
+                // };
+                return {};
+            });
+
+            // Due to the above problem, the output of this won't be correct, so we cannot verify it.
+            const [res] = await Promise.all([client.downloadAuthenticatedContent(mxcUrl), http.flushAllExpected()]);
+            expect(Object.keys(res)).toContain("data");
+            expect(Object.keys(res)).toContain("contentType");
+        });
+    });
+
     describe('downloadContent', () => {
         it('should call the right endpoint', async () => {
             const { client, http } = createTestClient();