fix(gpio): pinState() value incorrect in GPIO listeners

fix #9

Author: urish

src/gpio.spec.ts

@@ -68,5 +68,19 @@ describe('GPIO', () => {
       cpu.writeData(0x25, 0x2); // PORTB <- 0x2
       expect(port.pinState(1)).toEqual(PinState.InputPullUp);
     });
+
+    it('should reflect the current port state when called inside a listener', () => {
+      // Related issue: https://github.com/wokwi/avr8js/issues/9
+      const cpu = new CPU(new Uint16Array(1024));
+      const port = new AVRIOPort(cpu, portBConfig);
+      const listener = jest.fn(() => {
+        expect(port.pinState(0)).toBe(PinState.High);
+      });
+      port.addListener(listener);
+      expect(port.pinState(0)).toBe(PinState.Input);
+      cpu.writeData(0x24, 0x01); // DDRB <- 0x01
+      cpu.writeData(0x25, 0x01); // PORTB <- 0x01
+      expect(listener).toHaveBeenCalled();
+    });
   });
 });

src/gpio.ts

@@ -96,10 +96,11 @@ export class AVRIOPort {
   constructor(private cpu: CPU, private portConfig: AVRPortConfig) {
     cpu.writeHooks[portConfig.PORT] = (value: u8, oldValue: u8) => {
       const ddrMask = cpu.data[portConfig.DDR];
+      cpu.data[portConfig.PORT] = value;
       value &= ddrMask;
       cpu.data[portConfig.PIN] = (cpu.data[portConfig.PIN] & ~ddrMask) | value;
       this.writeGpio(value, oldValue & ddrMask);
-      // TODO: activate pullups if configured as an input pin
+      return true;
     };
     cpu.writeHooks[portConfig.PIN] = (value: u8) => {
       // Writing to 1 PIN toggles PORT bits