From 18ea4cc95fced337946c93d17ac1d41ceb9c829d Mon Sep 17 00:00:00 2001
From: Dorian Ignee <dorian.ignee@posterselect.de>
Date: Wed, 4 Dec 2024 11:11:39 +0100
Subject: [PATCH] fix #523: Test runner of cpu emulator page doesn't execute
 code that was passed from assembler page

add isEmpty() to Memory class
check for ROM.isEmpty() in cputst.step()
---
 simulator/src/cpu/memory.ts  | 4 ++++
 simulator/src/test/cputst.ts | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/simulator/src/cpu/memory.ts b/simulator/src/cpu/memory.ts
index dacd1fd4b..8979ddc88 100644
--- a/simulator/src/cpu/memory.ts
+++ b/simulator/src/cpu/memory.ts
@@ -127,6 +127,10 @@ export class Memory implements MemoryAdapter {
   [Symbol.iterator](): Iterable<number> {
     return this.map((_, v) => v);
   }
+
+  isEmpty(): boolean {
+    return this.memory.every((word) => word === 0);
+  }
 }
 
 export class SubMemory implements MemoryAdapter {
diff --git a/simulator/src/test/cputst.ts b/simulator/src/test/cputst.ts
index bc28f414c..8b041871a 100644
--- a/simulator/src/test/cputst.ts
+++ b/simulator/src/test/cputst.ts
@@ -55,7 +55,7 @@ export class CPUTest extends Test<CPUTestInstruction> {
   }
 
   override async step() {
-    if (!(this.hasLoad || this.fileLoaded)) {
+    if (!this.hasLoad && this.cpu.ROM.isEmpty()) {
       throw new Error(
         "Cannot execute the test without first loading an .asm or .hack file",
       );