fix: guard Transport scheduling against stopped clock and stale time

js/__tests__/logo.test.js

@@ -41,6 +41,13 @@ global.Synth = jest.fn().mockImplementation(() => ({
         get isAvailable() {
             return typeof global.Tone !== "undefined" && !!global.Tone.Transport;
         },
+        get state() {
+            if (this.isAvailable) return global.Tone.Transport.state;
+            return "stopped";
+        },
+        get isClockRunning() {
+            return this.isAvailable;
+        },
         start() {
             if (this.isAvailable) global.Tone.Transport.start();
         },
@@ -157,6 +164,9 @@ function makeSynth() {
             get isAvailable() {
                 return false;
             },
+            get isClockRunning() {
+                return false;
+            },
             cancel: jest.fn(),
             get seconds() {
                 return 0;
@@ -1001,6 +1011,9 @@ describe("Logo doStopTurtles", () => {
                     get isAvailable() {
                         return typeof global.Tone !== "undefined" && !!global.Tone.Transport;
                     },
+                    get isClockRunning() {
+                        return this.isAvailable;
+                    },
                     cancel() {
                         if (
                             this.isAvailable &&
@@ -1284,9 +1297,15 @@ describe("Logo runFromBlock", () => {
             });
             global.Tone = {
                 ...savedTone,
+                context: {
+                    get state() {
+                        return "running";
+                    }
+                },
                 Transport: {
                     start: jest.fn(),
                     stop: jest.fn(),
+                    state: "started",
                     schedule: scheduleSpy,
                     cancel: jest.fn(),
                     getSecondsAtTime: getSecondsAtTimeMock,

js/logo.js

@@ -1695,9 +1695,14 @@ class Logo {
                 logo.turtleDelay === 0 &&
                 delay > 0 &&
                 logo.synth.transport.isAvailable &&
+                logo.synth.transport.state === "started" &&
+                logo.synth.transport.isClockRunning &&
                 tur._transportTime !== null
             ) {
-                const transportTime = tur._transportTime + delay / 1000;
+                const transportTime = Math.max(
+                    tur._transportTime + delay / 1000,
+                    logo.synth.transport.seconds
+                );
                 tur.delayParameters = { blk: blk, flow: isflow, arg: receivedArg };
                 tur._transportEventId = logo.synth.transport.schedule(audioContextTime => {
                     const tur2 = logo.activity.turtles.ithTurtle(turtle);

js/utils/synthutils.js

@@ -472,6 +472,16 @@ const transport = {
     get isAvailable() {
         return typeof Tone !== "undefined" && Tone.Transport;
     },
+    get state() {
+        if (this.isAvailable) return Tone.Transport.state;
+        return "stopped";
+    },
+    get isClockRunning() {
+        if (this.isAvailable && typeof Tone !== "undefined" && Tone.context) {
+            return Tone.context.state === "running";
+        }
+        return false;
+    },
     start() {
         if (this.isAvailable) Tone.Transport.start();
     },