Use fs/promises in the Node.js-specific code in the src/-folder

This is available in all Node.js versions that we currently support, and using it allows us to remove callback-functions; please see https://nodejs.org/docs/latest-v18.x/api/fs.html#promises-api

src/display/node_stream.js

@@ -424,21 +424,22 @@ class PDFNodeStreamFsFullReader extends BaseFullReader {
       path = path.replace(/^\//, "");
     }
 
-    fs.lstat(path, (error, stat) => {
-      if (error) {
-        if (error.code === "ENOENT") {
-          error = new MissingPDFException(`Missing PDF "${path}".`);
-        }
-        this._storedError = error;
-        this._headersCapability.reject(error);
-        return;
-      }
+    fs.promises.lstat(path).then(
+      stat => {
         // Setting right content length.
         this._contentLength = stat.size;
 
         this._setReadableStream(fs.createReadStream(path));
         this._headersCapability.resolve();
-    });
+      },
+      error => {
+        if (error.code === "ENOENT") {
+          error = new MissingPDFException(`Missing PDF "${path}".`);
+        }
+        this._storedError = error;
+        this._headersCapability.reject(error);
+      }
+    );
   }
 }
 

src/display/node_utils.js

@@ -71,15 +71,7 @@ if (typeof PDFJSDev !== "undefined" && !PDFJSDev.test("SKIP_BABEL")) {
 }
 
 const fetchData = function (url) {
-  return new Promise((resolve, reject) => {
-    fs.readFile(url, (error, data) => {
-      if (error || !data) {
-        reject(new Error(error));
-        return;
-      }
-      resolve(new Uint8Array(data));
-    });
-  });
+  return fs.promises.readFile(url).then(data => new Uint8Array(data));
 };
 
 class NodeFilterFactory extends BaseFilterFactory {}