Support for screen-sharing using multi-stream VoIP (MSC3077)

spec/unit/webrtc/call.spec.ts

@@ -16,6 +16,7 @@ limitations under the License.
 
 import { TestClient } from '../../TestClient';
 import { MatrixCall, CallErrorCode, CallEvent } from '../../../src/webrtc/call';
+import { SDPStreamMetadataKey, SDPStreamMetadataPurpose } from '../../../src/webrtc/callEventTypes';
 
 const DUMMY_SDP = (
     "v=0\r\n" +
@@ -298,4 +299,65 @@ describe('Call', function() {
         // Hangup to stop timers
         call.hangup(CallErrorCode.UserHangup, true);
     });
+
+    it("should map SDPStreamMetadata to feeds", async () => {
+        const callPromise = call.placeVoiceCall();
+        await client.httpBackend.flush();
+        await callPromise;
+
+        call.getOpponentMember = () => {
+            return { userId: "@bob:bar.uk" };
+        };
+
+        await call.onAnswerReceived({
+            getContent: () => {
+                return {
+                    version: 1,
+                    call_id: call.callId,
+                    party_id: 'party_id',
+                    answer: {
+                        sdp: DUMMY_SDP,
+                    },
+                    [SDPStreamMetadataKey]: {
+                        "stream_id": {
+                            purpose: SDPStreamMetadataPurpose.Usermedia,
+                        },
+                    },
+                };
+            },
+        });
+
+        call.pushRemoteFeed({ id: "stream_id" });
+        expect(call.getFeeds().find((feed) => {
+            return feed.stream.id === "stream_id";
+        })?.purpose).toBe(SDPStreamMetadataPurpose.Usermedia);
+    });
+
+    it("should fallback to replaceTrack() if the other side doesn't support SPDStreamMetadata", async () => {
+        const callPromise = call.placeVoiceCall();
+        await client.httpBackend.flush();
+        await callPromise;
+
+        call.getOpponentMember = () => {
+            return { userId: "@bob:bar.uk" };
+        };
+
+        await call.onAnswerReceived({
+            getContent: () => {
+                return {
+                    version: 1,
+                    call_id: call.callId,
+                    party_id: 'party_id',
+                    answer: {
+                        sdp: DUMMY_SDP,
+                    },
+                };
+            },
+        });
+
+        call.setScreensharingEnabledWithoutMetadataSupport = jest.fn();
+
+        call.setScreensharingEnabled(true);
+        expect(call.setScreensharingEnabledWithoutMetadataSupport).toHaveBeenCalled();
+    });
 });