openvidu-browser: Reduce 2 nesting levels in WebRtcPeer.createOffer

openvidu-browser/src/OpenViduInternal/WebRtcPeer/WebRtcPeer.ts

@@ -120,26 +120,53 @@ export class WebRtcPeer {
         }
     }
 
+    // DEPRECATED LEGACY METHOD: Old WebRTC versions don't implement
+    // Transceivers, and instead depend on the deprecated
+    // "offerToReceiveAudio" and "offerToReceiveVideo".
+    private createOfferLegacy(): Promise<RTCSessionDescriptionInit> {
+        if (!!this.configuration.mediaStream) {
+            this.deprecatedPeerConnectionTrackApi();
+        }
+
+        const hasAudio = this.configuration.mediaConstraints.audio;
+        const hasVideo = this.configuration.mediaConstraints.video;
+
+        const options: RTCOfferOptions = {
+            offerToReceiveAudio: this.configuration.mode !== "sendonly" && hasAudio,
+            offerToReceiveVideo: this.configuration.mode !== "sendonly" && hasVideo,
+        };
+
+        logger.debug("[createOfferLegacy] RTCPeerConnection.createOffer() options:", JSON.stringify(options));
+
+        return this.pc.createOffer(options);
+    }
+
     /**
-     * Creates an SDP offer from the local RTCPeerConnection to send to the other peer
+     * Creates an SDP offer from the local RTCPeerConnection to send to the other peer.
-     * Only if the negotiation was initiated by this peer
+     * Only if the negotiation was initiated by this peer.
      */
-    createOffer(): Promise<RTCSessionDescriptionInit> {
+    async createOffer(): Promise<RTCSessionDescriptionInit> {
-        return new Promise(async (resolve, reject) => {
         // TODO: Delete this conditional when all supported browsers are
         // modern enough to implement the Transceiver methods.
-            if ("addTransceiver" in this.pc) {
+        if (!("addTransceiver" in this.pc)) {
+            logger.warn(
+                "[createOffer] Method RTCPeerConnection.addTransceiver() is NOT available; using LEGACY offerToReceive{Audio,Video}"
+            );
+            return this.createOfferLegacy();
+        } else {
             logger.debug("[createOffer] Method RTCPeerConnection.addTransceiver() is available; using it");
+        }
 
         // Spec doc: https://w3c.github.io/webrtc-pc/#dom-rtcpeerconnection-addtransceiver
 
         if (this.configuration.mode !== "recvonly") {
-                    // To send media, assume that all desired media tracks
+            // To send media, assume that all desired media tracks have been
-                    // have been already added by higher level code to our
+            // already added by higher level code to our MediaStream.
-                    // MediaStream.
 
             if (!this.configuration.mediaStream) {
-                        return reject(new Error(`${this.configuration.mode} direction requested, but no stream was configured to be sent`));
+                throw new Error(
+                    `[WebRtcPeer.createOffer] Direction is '${this.configuration.mode}', but no stream was configured to be sent`
+                );
             }
 
             for (const track of this.configuration.mediaStream.getTracks()) {
@@ -167,7 +194,6 @@ export class WebRtcPeer {
                         logger.info(`[createOffer] Video track Content Hint set: '${track.contentHint}'`);
                     }
 
-                            logger.info(`[createOffer] this.configuration.simulcast: ${this.configuration.simulcast}`);
                     if (this.configuration.simulcast) {
                         // Check if the requested size is enough to ask for 3 layers.
                         const trackSettings = track.getSettings();
@@ -202,7 +228,7 @@ export class WebRtcPeer {
                             const encoding: RTCRtpEncodingParameters = {
                                 rid: "rDiv" + layerDiv.toString(),
 
-                                        // @ts-ignore: Property missing from DOM types.
+                                // @ts-ignore -- Property missing from DOM types.
                                 scalabilityMode: "L1T1",
                             };
 
@@ -210,7 +236,7 @@ export class WebRtcPeer {
                                 // Prioritize best resolution, for maximum picture detail.
                                 encoding.scaleResolutionDownBy = 1.0;
 
-                                        // @ts-ignore: Property missing from DOM types.
+                                // @ts-ignore -- Property missing from DOM types.
                                 encoding.maxFramerate = Math.floor(30 / layerDiv);
                                 // encoding.maxFramerate = (l === 2) ? 30 : Math.floor(30 / (2 * layerDiv)); // TESTING
                             } else {
@@ -229,9 +255,7 @@ export class WebRtcPeer {
                     let needSetParams = false;
 
                     if (!("degradationPreference" in sendParams)) {
-                                logger.debug(
+                        logger.debug(`[createOffer] RTCRtpSendParameters.degradationPreference attribute not present`);
-                                    `[createOffer] RTCRtpSendParameters.degradationPreference attribute not present`
-                                );
                         // Asked about why this might happen. Check it:
                         // https://groups.google.com/g/discuss-webrtc/c/R8Xug-irfRY
 
@@ -311,40 +335,7 @@ export class WebRtcPeer {
             }
         }
 
-                this.pc
+        return this.pc.createOffer();
-                    .createOffer()
-                    .then((sdpOffer) => resolve(sdpOffer))
-                    .catch((error) => reject(error));
-            } else {
-                logger.warn("[createOffer] Method RTCPeerConnection.addTransceiver() is NOT available; using LEGACY offerToReceive{Audio,Video}");
-
-                // DEPRECATED LEGACY METHOD: Old WebRTC versions don't implement
-                // Transceivers, and instead depend on the deprecated
-                // "offerToReceiveAudio" and "offerToReceiveVideo".
-
-                if (!!this.configuration.mediaStream) {
-                    this.deprecatedPeerConnectionTrackApi();
-                }
-
-                const hasAudio = this.configuration.mediaConstraints.audio;
-                const hasVideo = this.configuration.mediaConstraints.video;
-
-                const options: RTCOfferOptions = {
-                    offerToReceiveAudio:
-                        this.configuration.mode !== "sendonly" && hasAudio,
-                    offerToReceiveVideo:
-                        this.configuration.mode !== "sendonly" && hasVideo,
-                };
-
-                logger.debug("RTCPeerConnection.createOffer() options:", JSON.stringify(options));
-
-                this.pc
-                    // @ts-ignore - Compiler is too clever and thinks this branch will never execute.
-                    .createOffer(options)
-                    .then((sdpOffer) => resolve(sdpOffer))
-                    .catch((error) => reject(error));
-            }
-        });
     }
 
     deprecatedPeerConnectionTrackApi() {