diff --git a/src/controller/audio-stream-controller.ts b/src/controller/audio-stream-controller.ts
index de2d338a523..c890007b4cb 100644
--- a/src/controller/audio-stream-controller.ts
+++ b/src/controller/audio-stream-controller.ts
@@ -251,9 +251,9 @@ class AudioStreamController
 
   private doTickIdle() {
     const { hls, levels, media, trackId } = this;
-
     const config = hls.config;
-    if (!levels) {
+
+    if (!levels || !levels[trackId]) {
       return;
     }
 
@@ -270,9 +270,6 @@ class AudioStreamController
       return;
     }
 
-    if (!levels || !levels[trackId]) {
-      return;
-    }
     const levelInfo = levels[trackId];
 
     const trackDetails = levelInfo.details;
diff --git a/src/controller/base-stream-controller.ts b/src/controller/base-stream-controller.ts
index 43bca8124ca..db337f8ad62 100644
--- a/src/controller/base-stream-controller.ts
+++ b/src/controller/base-stream-controller.ts
@@ -41,6 +41,9 @@ import type { HlsEventEmitter } from '../events';
 import type { NetworkComponentAPI } from '../types/component-api';
 import type { SourceBufferName } from '../types/buffer';
 
+type ResolveFragLoaded = (FragLoadedEndData) => void;
+type RejectFragLoaded = (LoadError) => void;
+
 export const State = {
   STOPPED: 'STOPPED',
   IDLE: 'IDLE',
@@ -478,9 +481,8 @@ export default class BaseStreamController
     // If we did not load parts, or loaded all parts, we have complete (not partial) fragment data
     const complete =
       !partsLoaded ||
-      (partsLoaded &&
-        (partsLoaded.length === 0 ||
-          partsLoaded.some((fragLoaded) => !fragLoaded)));
+      partsLoaded.length === 0 ||
+      partsLoaded.some((fragLoaded) => !fragLoaded);
     const chunkMeta = new ChunkMetadata(
       frag.level,
       frag.sn as number,
@@ -570,7 +572,7 @@ export default class BaseStreamController
     progressCallback: FragmentLoadProgressCallback
   ): Promise<PartsLoadedData | null> {
     return new Promise(
-      (resolve: (FragLoadedEndData) => void, reject: (LoadError) => void) => {
+      (resolve: ResolveFragLoaded, reject: RejectFragLoaded) => {
         const partsLoaded: FragLoadedData[] = [];
         const loadPartIndex = (index: number) => {
           const part = partList[index];
diff --git a/src/controller/cap-level-controller.ts b/src/controller/cap-level-controller.ts
index b0f55a01af0..9c616ba051f 100644
--- a/src/controller/cap-level-controller.ts
+++ b/src/controller/cap-level-controller.ts
@@ -244,7 +244,7 @@ class CapLevelController implements ComponentAPI {
     width: number,
     height: number
   ): number {
-    if (!levels || (levels && !levels.length)) {
+    if (!levels || !levels.length) {
       return -1;
     }
 
diff --git a/src/controller/level-helper.ts b/src/controller/level-helper.ts
index 7621073dd68..08ff0829e9d 100644
--- a/src/controller/level-helper.ts
+++ b/src/controller/level-helper.ts
@@ -369,7 +369,7 @@ export function computeReloadInterval(
     timeSinceLastModified > 0 && timeSinceLastModified < reloadInterval * 3;
   const roundTrip = stats.loading.end - stats.loading.start;
 
-  let estimatedTimeUntilUpdate = reloadInterval;
+  let estimatedTimeUntilUpdate;
   let availabilityDelay = newDetails.availabilityDelay;
   // let estimate = 'average';
 
diff --git a/src/controller/timeline-controller.ts b/src/controller/timeline-controller.ts
index ea49a5d4fb2..994f9864010 100644
--- a/src/controller/timeline-controller.ts
+++ b/src/controller/timeline-controller.ts
@@ -428,10 +428,8 @@ export class TimelineController implements ComponentAPI {
     if (data.frag.type === PlaylistLevelType.MAIN) {
       const sn = data.frag.sn;
       if (sn !== lastSn + 1) {
-        if (cea608Parser1 && cea608Parser2) {
-          cea608Parser1.reset();
-          cea608Parser2.reset();
-        }
+        cea608Parser1.reset();
+        cea608Parser2.reset();
       }
       this.lastSn = sn as number;
     }
diff --git a/src/crypt/aes-decryptor.ts b/src/crypt/aes-decryptor.ts
index 0293b59f5e5..161570e2629 100644
--- a/src/crypt/aes-decryptor.ts
+++ b/src/crypt/aes-decryptor.ts
@@ -326,7 +326,6 @@ export default class AESDecryptor {
         (invSBOX[(s1 >> 8) & 0xff] << 8) ^
         invSBOX[s2 & 0xff] ^
         invKeySchedule[ksRow + 3];
-      ksRow = ksRow + 3;
 
       // Write
       outputInt32[offset] = swapWord(t0 ^ initVector0);
diff --git a/src/remux/mp4-remuxer.ts b/src/remux/mp4-remuxer.ts
index 9c7b09f31a9..e556195d039 100644
--- a/src/remux/mp4-remuxer.ts
+++ b/src/remux/mp4-remuxer.ts
@@ -457,7 +457,6 @@ export default class MP4Remuxer implements Remuxer {
         }
       }
       firstDTS = inputSamples[0].dts;
-      lastDTS = inputSamples[nbSamples - 1].dts;
     }
 
     // if fragment are contiguous, detect hole/overlapping between fragments
diff --git a/src/types/remuxer.ts b/src/types/remuxer.ts
index 320108bdbab..10bb2823a03 100644
--- a/src/types/remuxer.ts
+++ b/src/types/remuxer.ts
@@ -2,7 +2,6 @@ import type { TrackSet } from './track';
 import {
   DemuxedAudioTrack,
   DemuxedMetadataTrack,
-  DemuxedTrack,
   DemuxedUserdataTrack,
   DemuxedVideoTrack,
   MetadataSample,
diff --git a/src/utils/cea-608-parser.ts b/src/utils/cea-608-parser.ts
index d242cff215f..6e8f02fb7c5 100644
--- a/src/utils/cea-608-parser.ts
+++ b/src/utils/cea-608-parser.ts
@@ -1299,7 +1299,7 @@ class Cea608Parser {
    * @returns {Object} pacData with style parameters.
    */
   interpretPAC(row: number, byte: number): PACData {
-    let pacIndex = byte;
+    let pacIndex;
     const pacData: PACData = {
       color: null,
       italics: false,
@@ -1353,7 +1353,7 @@ class Cea608Parser {
     }
     if (charCode1 >= 0x11 && charCode1 <= 0x13) {
       // Special character
-      let oneCode = b;
+      let oneCode;
       if (charCode1 === 0x11) {
         oneCode = b + 0x50;
       } else if (charCode1 === 0x12) {
diff --git a/src/utils/mp4-tools.ts b/src/utils/mp4-tools.ts
index 785611ebfe2..37119db36fd 100644
--- a/src/utils/mp4-tools.ts
+++ b/src/utils/mp4-tools.ts
@@ -123,7 +123,7 @@ type SidxInfo = {
 
 export function parseSegmentIndex(initSegment: Uint8Array): SidxInfo | null {
   const moovBox = findBox(initSegment, ['moov']);
-  const moov = moovBox ? moovBox[0] : null;
+  const moov = moovBox[0];
   const moovEndOffset = moov ? moov.end : null; // we need this in case we need to chop of garbage of the end of current data
 
   const sidxBox = findBox(initSegment, ['sidx']);
diff --git a/tools/mp4-inspect.js b/tools/mp4-inspect.js
index 60b2158e018..cf803c9b93a 100644
--- a/tools/mp4-inspect.js
+++ b/tools/mp4-inspect.js
@@ -182,11 +182,10 @@ var // this is the start of a huge multi-line var decl
           flags: new Uint8Array(data.subarray(1, 4)),
           handlerType: parseType(data.subarray(8, 12)),
           name: '',
-        },
-        i = 8;
+        };
 
       // parse out the name field
-      for (i = 24; i < data.byteLength; i++) {
+      for (var i = 24; i < data.byteLength; i++) {
         if (data[i] === 0x00) {
           // the name field is null-terminated
           i++;