initial attempt at time travel debugging

biome.json

@@ -0,0 +1,5 @@
+{
+  "files": {
+    "ignore": ["**"]
+  }
+}

build.config.mjs

@@ -12,6 +12,7 @@ const extEntries = [
   'src/ext/worker.js',
   'src/ext/eventsource.js',
   'src/ext/tailwind.js',
+  'src/ext/ttd.js',
 ]
 
 const shared = {

src/core/runtime/runtime.js

@@ -94,9 +94,28 @@ export class Runtime {
 
         unifiedExec(command, ctx) {
             while (true) {
+	            const target = ctx.meta.owner || ctx.me;
+            	const eventResult = this.triggerEvent(
+                    target,
+                    "hyperscript:beforeEval",
+                    { command: command, ctx: ctx },
+                );
+                if (!eventResult) {
+                    if (ctx.meta.onHalt) ctx.meta.onHalt();
+                    return;
+       	    	}
+                let afterFired = false;
+
                 try {
                     var next = this.unifiedEval(command, ctx);
                 } catch (e) {
+		            this.triggerEvent(target, "hyperscript:afterEval", {
+                        command: command,
+                        ctx: ctx,
+                        error: e,
+                    });
+                    afterFired = true;
+
                     if (ctx.meta.handlingFinally) {
                         console.error(" Exception in finally block: ", e);
                         next = Runtime.HALT;
@@ -113,6 +132,16 @@ export class Runtime {
                         }
                     }
                 }
+
+		        // afterEval should only fire once per unifiedEval invocation. if unifiedEval threw, don't fire the event again
+                if (!afterFired) {
+                    this.triggerEvent(target, "hyperscript:afterEval", {
+                        command: command,
+                        ctx: ctx,
+                        next: next,
+                    });
+                }
+
                 if (next == null) {
                     throw new Error("Command " + (command.type || "unknown") + " did not return a next element to execute");
                 } else if (next.then) {