make play button sticky

closes https://github.com/gaearon/rscexplorer/pull/6

Co-authored-by: Michael Chen <[e-mail]>

src/client/ui/LivePreview.css

···
   color: #ffd54f;
 }
 
+.LivePreview-controlBtn--playing:hover:not(:disabled) {
+  color: #ffe566;
+}
+
 .LivePreview-controlBtn--step {
   background: #ffd54f;
   color: #000;

src/client/ui/LivePreview.tsx

···
 
   useEffect(() => {
     if (!isPlaying || isAtEnd) {
-      // eslint-disable-next-line react-hooks/set-state-in-effect
-      if (isAtEnd) setIsPlaying(false);
       return;
     }
     const timer = setTimeout(() => onStep(), 300);
     return () => clearTimeout(timer);
   }, [isPlaying, isAtEnd, onStep, cursor]);
 
-  useEffect(() => {
-    // eslint-disable-next-line react-hooks/set-state-in-effect
-    setIsPlaying(false);
-  }, [totalChunks]);
-
   const showPlaceholder = entries.length === 0 || cursor === 0;
 
   const handlePlayPause = (): void => setIsPlaying(!isPlaying);
···
     onStep();
   };
   const handleSkip = (): void => {
-    setIsPlaying(false);
     onSkip();
   };
   const handleReset = (): void => {
···
             </svg>
           </button>
           <button
-            className={`LivePreview-controlBtn${isPlaying ? " LivePreview-controlBtn--playing" : ""}`}
+            className={`LivePreview-controlBtn${isPlaying && !isAtEnd ? " LivePreview-controlBtn--playing" : ""}`}
             onClick={handlePlayPause}
-            disabled={isLoading || isAtEnd}
+            disabled={isLoading}
             aria-label={isPlaying ? "Pause" : "Play"}
             title={isPlaying ? "Pause" : "Play"}
           >

src/client/ui/Workspace.tsx

···
   }
 
   const timeline = session?.timeline ?? loadingTimeline;
+
   const { entries, cursor, totalChunks, isAtStart, isAtEnd, isStreaming } = useSyncExternalStore(
     timeline.subscribe,
     timeline.getSnapshot,

src/client/workspace-session.ts

···
       callServer: this.callServer.bind(this),
     });
     this.timeline.addAction(actionName, argsDisplay, stream);
+    if (stream.error) {
+      throw stream.error;
+    }
     return stream;
   }