Eslint upgrade

emulator/Emulator.js

@@ -50,7 +50,6 @@ export default class Emulator {
     }
 
     window.requestAnimationFrame(() => this.refreshDisplay());
-
   }
 
   refreshDisplay() {

emulator/apu/Apu.js

@@ -57,10 +57,7 @@ export default class Apu {
   }
 
   generateSamples() {
-    const samples = this.channels.map((channel) => {
-      return channel.generateSample();
-    });
-
+    const samples = this.channels.map(channel => channel.generateSample());
     this.player.addSamples(samples);
   }
 }

emulator/apu/channels/SquareChannel.js

@@ -77,7 +77,7 @@ export default class SquareChannel {
   }
 
   generateSample() {
-    if (this.registers.isChannelEnabled() && this.registers.isDacEnabled() && this.isDutyCycleActive()) {
+    if (this.registers.isChannelEnabled() && this.isDutyCycleActive()) {
       return this.volume / 45;
     } else {
       return 0;

emulator/apu/channels/registers/SquareChannelRegisters.js

@@ -21,17 +21,16 @@ export default class SquareChannelRegisters {
   }
 
   isChannelEnabled() {
-    return this.read(4) & 0x80;
+    const isChannelEnabled = this.read(4) & 0x80;
+    const isDacEnabled = this.read(2) & 0xF8;
+
+    return isChannelEnabled && isDacEnabled;
   }
 
   getVolume() {
     return this.read(2) >> 4;
   }
 
-  isDacEnabled() {
-    return this.read(2) & 0xF8;
-  }
-
   getActiveDutyCycle() {
     return this.read(1) >> 6;
   }

emulator/gpu/renderers/SpriteRenderer.js

@@ -22,6 +22,8 @@ export default class SpriteRenderer extends AbstractRenderer {
           return sprite;
         }
       }
+
+      return undefined;
     });
   }
 
@@ -41,6 +43,7 @@ export default class SpriteRenderer extends AbstractRenderer {
     const { tileNumber } = sprite;
     const spriteHeight = this.spriteManager.getSpriteHeight();
 
+    // eslint-disable-next-line no-param-reassign
     sprite.color = this.calculatePixelColor(tileNumber, spriteRow, spriteColumn, spriteHeight);
   }
 

emulator/mmu/registers/MemoryRegisterSet.js

@@ -9,7 +9,7 @@ import TimerControllerRegister from './timer/TimerControllerRegister.js';
 import TimerDividerRegister from './timer/TimerDividerRegister.js';
 import InterruptRequestRegister from './interrupts/InterruptRequestRegister.js';
 import InterruptEnabledRegister from './interrupts/InterruptEnabledRegister.js';
-import TestRegister from './sound/TestRegister.js';
+// import TestRegister from './sound/TestRegister.js';
 
 export default class MemoryRegisterSet {
   constructor(mmu) {