diff --git a/.github/workflows/nodejs.yml b/.github/workflows/nodejs.yml
index 6857e8c..fb94bc8 100644
--- a/.github/workflows/nodejs.yml
+++ b/.github/workflows/nodejs.yml
@@ -42,7 +42,7 @@ jobs:
         uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node-version }}
-          cache: 'pnpm'
+          cache: "pnpm"
 
       - name: Install dependencies
         run: pnpm install
diff --git a/src/index.js b/src/index.js
index f3d65e1..b9d85cd 100644
--- a/src/index.js
+++ b/src/index.js
@@ -218,17 +218,17 @@ function wdm(compiler, options = {}) {
     if (
       Array.isArray(/** @type {MultiCompiler} */ (context.compiler).compilers)
     ) {
-      const compiler = /** @type {MultiCompiler} */ (context.compiler);
-      const watchOptions = compiler.compilers.map(
+      const multiCompiler = /** @type {MultiCompiler} */ (context.compiler);
+      const watchOptions = multiCompiler.compilers.map(
         (childCompiler) => childCompiler.options.watchOptions || {},
       );
 
-      context.watching = compiler.watch(watchOptions, errorHandler);
+      context.watching = multiCompiler.watch(watchOptions, errorHandler);
     } else {
-      const compiler = /** @type {Compiler} */ (context.compiler);
-      const watchOptions = compiler.options.watchOptions || {};
+      const singleCompiler = /** @type {Compiler} */ (context.compiler);
+      const watchOptions = singleCompiler.options.watchOptions || {};
 
-      context.watching = compiler.watch(watchOptions, errorHandler);
+      context.watching = singleCompiler.watch(watchOptions, errorHandler);
     }
   }
 
diff --git a/src/middleware.js b/src/middleware.js
index a1217d5..32a1fb5 100644
--- a/src/middleware.js
+++ b/src/middleware.js
@@ -103,7 +103,7 @@ function parseHttpDate(date) {
   const timestamp = date && Date.parse(date);
 
   // istanbul ignore next: guard against date.js Date.parse patching
-  return typeof timestamp === "number" ? timestamp : NaN;
+  return typeof timestamp === "number" ? timestamp : Number.NaN;
 }
 
 const CACHE_CONTROL_NO_CACHE_REGEXP = /(?:^|,)\s*?no-cache\s*?(?:,|$)/;
@@ -252,6 +252,7 @@ function wrapper(context) {
       }
 
       // Send basic response
+      // eslint-disable-next-line no-param-reassign
       res.statusCode = status;
       res.setHeader("Content-Type", "text/html; charset=utf-8");
       res.setHeader("Content-Security-Policy", "default-src 'none'");
@@ -305,12 +306,12 @@ function wrapper(context) {
 
         // A recipient MUST ignore the If-Unmodified-Since header field if the
         // received field-value is not a valid HTTP-date.
-        if (!isNaN(unmodifiedSince)) {
+        if (!Number.isNaN(unmodifiedSince)) {
           const lastModified = parseHttpDate(
             /** @type {string} */ (res.getHeader("Last-Modified")),
           );
 
-          return isNaN(lastModified) || lastModified > unmodifiedSince;
+          return Number.isNaN(lastModified) || lastModified > unmodifiedSince;
         }
       }
 
@@ -546,6 +547,7 @@ function wrapper(context) {
 
         // For Koa
         if (res.statusCode === 404) {
+          // eslint-disable-next-line no-param-reassign
           res.statusCode = 200;
         }
 
@@ -558,6 +560,7 @@ function wrapper(context) {
               (res.getHeader("Last-Modified")),
           })
         ) {
+          // eslint-disable-next-line no-param-reassign
           res.statusCode = 304;
 
           // Remove content header fields
@@ -597,7 +600,8 @@ function wrapper(context) {
           });
 
           return;
-        } else if (parsedRanges === -2) {
+        }
+        if (parsedRanges === -2) {
           context.logger.error(
             "A malformed 'Range' header was provided. A regular response will be sent for this request.",
           );
@@ -609,6 +613,7 @@ function wrapper(context) {
 
         if (parsedRanges !== -2 && parsedRanges.length === 1) {
           // Content-Range
+          // eslint-disable-next-line no-param-reassign
           res.statusCode = 206;
           res.setHeader(
             "Content-Range",
@@ -648,6 +653,7 @@ function wrapper(context) {
       if (req.method === "HEAD") {
         // For Koa
         if (res.statusCode === 404) {
+          // eslint-disable-next-line no-param-reassign
           res.statusCode = 200;
         }
 
diff --git a/src/utils/getFilenameFromUrl.js b/src/utils/getFilenameFromUrl.js
index 67852ee..ff489fc 100644
--- a/src/utils/getFilenameFromUrl.js
+++ b/src/utils/getFilenameFromUrl.js
@@ -125,7 +125,8 @@ function getFilenameFromUrl(context, url, extra = {}) {
         foundFilename = filename;
 
         break;
-      } else if (
+      }
+      if (
         extra.stats.isDirectory() &&
         (typeof options.index === "undefined" || options.index)
       ) {
@@ -138,6 +139,7 @@ function getFilenameFromUrl(context, url, extra = {}) {
         filename = path.join(filename, indexValue);
 
         try {
+          // eslint-disable-next-line no-param-reassign
           extra.stats =
             /** @type {import("fs").statSync} */
             (context.outputFileSystem.statSync)(filename);
diff --git a/test/middleware.test.js b/test/middleware.test.js
index a86098a..c2eb3d3 100644
--- a/test/middleware.test.js
+++ b/test/middleware.test.js
@@ -1664,7 +1664,7 @@ describe.each([
             undefined,
             {
               setupMiddlewares: (middlewares) => {
-                middlewares.unshift((req, res, next) => {
+                middlewares.unshift((_req, res, next) => {
                   // Express API
                   if (res.set) {
                     res.set(