diff --git a/src/core/annotation.js b/src/core/annotation.js
index 1c6877972..c87f99f4b 100644
--- a/src/core/annotation.js
+++ b/src/core/annotation.js
@@ -1686,12 +1686,12 @@ class MarkupAnnotation extends Annotation {
       buffer.push(`${fillColor[0]} ${fillColor[1]} ${fillColor[2]} rg`);
     }
 
-    let pointsArray = this.data.quadPoints;
-    if (!pointsArray) {
-      // If there are no quadpoints, the rectangle should be used instead.
-      // Convert the rectangle definition to a points array similar to how the
-      // quadpoints are defined.
-      pointsArray = Float32Array.from([
+    // If there are no quadpoints, the rectangle should be used instead.
+    // Convert the rectangle definition to a points array similar to how the
+    // quadpoints are defined.
+    const pointsArray =
+      this.data.quadPoints ||
+      Float32Array.from([
         this.rectangle[0],
         this.rectangle[3],
         this.rectangle[2],
@@ -1701,7 +1701,6 @@ class MarkupAnnotation extends Annotation {
         this.rectangle[2],
         this.rectangle[1],
       ]);
-    }
 
     for (let i = 0, ii = pointsArray.length; i < ii; i += 8) {
       const [mX, MX, mY, MY] = pointsCallback(
@@ -1755,11 +1754,8 @@ class MarkupAnnotation extends Annotation {
   }
 
   static async createNewAnnotation(xref, annotation, changes, params) {
-    if (!annotation.ref) {
-      annotation.ref = xref.getNewTemporaryRef();
-    }
+    const annotationRef = (annotation.ref ||= xref.getNewTemporaryRef());
 
-    const annotationRef = annotation.ref;
     const ap = await this.createNewAppearanceStream(annotation, xref, params);
     let annotationDict;
 
diff --git a/src/core/catalog.js b/src/core/catalog.js
index 00524c32e..a38be8f9a 100644
--- a/src/core/catalog.js
+++ b/src/core/catalog.js
@@ -567,10 +567,7 @@ class Catalog {
       const onParsed = [];
       if (Array.isArray(refs)) {
         for (const value of refs) {
-          if (!(value instanceof Ref)) {
-            continue;
-          }
-          if (groupRefCache.has(value)) {
+          if (value instanceof Ref && groupRefCache.has(value)) {
             onParsed.push(value.toString());
           }
         }
@@ -629,7 +626,7 @@ class Catalog {
         return null;
       }
       const nestedOrder = parseOrder(value.slice(1), nestedLevels);
-      if (!nestedOrder || !nestedOrder.length) {
+      if (!nestedOrder?.length) {
         return null;
       }
       return { name: stringToPDFString(nestedName), order: nestedOrder };
diff --git a/src/core/ccitt.js b/src/core/ccitt.js
index ac204bd80..8a57a5dbe 100644
--- a/src/core/ccitt.js
+++ b/src/core/ccitt.js
@@ -466,7 +466,7 @@ const blackTable3 = [
  */
 class CCITTFaxDecoder {
   constructor(source, options = {}) {
-    if (!source || typeof source.next !== "function") {
+    if (typeof source?.next !== "function") {
       throw new Error('CCITTFaxDecoder - invalid "source" parameter.');
     }
     this.source = source;
diff --git a/src/core/decrypt_stream.js b/src/core/decrypt_stream.js
index 99dfd4ffa..ee2fff21f 100644
--- a/src/core/decrypt_stream.js
+++ b/src/core/decrypt_stream.js
@@ -36,7 +36,7 @@ class DecryptStream extends DecodeStream {
       chunk = this.str.getBytes(chunkSize);
       this.initialized = true;
     }
-    if (!chunk || chunk.length === 0) {
+    if (!chunk?.length) {
       this.eof = true;
       return;
     }
diff --git a/src/core/font_renderer.js b/src/core/font_renderer.js
index 37342fc30..271f7302c 100644
--- a/src/core/font_renderer.js
+++ b/src/core/font_renderer.js
@@ -818,7 +818,7 @@ class CompiledFont {
   }
 
   compileGlyph(code, glyphId) {
-    if (!code || code.length === 0 || code[0] === 14) {
+    if (!code?.length || code[0] === 14) {
       return NOOP;
     }
 
diff --git a/src/core/xref.js b/src/core/xref.js
index 75e5d1626..669af0ed8 100644
--- a/src/core/xref.js
+++ b/src/core/xref.js
@@ -310,18 +310,15 @@ class XRef {
     if (!("streamState" in this)) {
       // Stores state of the stream as we process it so we can resume
       // from middle of stream in case of missing data error
-      const streamParameters = stream.dict;
-      const byteWidths = streamParameters.get("W");
-      let range = streamParameters.get("Index");
-      if (!range) {
-        range = [0, streamParameters.get("Size")];
-      }
+      const { dict, pos } = stream;
+      const byteWidths = dict.get("W");
+      const range = dict.get("Index") || [0, dict.get("Size")];
 
       this.streamState = {
         entryRanges: range,
         byteWidths,
         entryNum: 0,
-        streamPos: stream.pos,
+        streamPos: pos,
       };
     }
     this.readXRefStream(stream);