Use more logical assignment in the code-base

examples/mobile-viewer/viewer.mjs

@@ -158,7 +158,7 @@ const PDFViewerApplication = {
     );
 
     let pdfTitle;
-    if (metadata && metadata.has("dc:title")) {
+    if (metadata?.has("dc:title")) {
       const title = metadata.get("dc:title");
       // Ghostscript sometimes returns 'Untitled', so prevent setting the
       // title to 'Untitled.
@@ -166,10 +166,7 @@ const PDFViewerApplication = {
         pdfTitle = title;
       }
     }
-
-    if (!pdfTitle && info && info.Title) {
-      pdfTitle = info.Title;
-    }
+    pdfTitle ||= info?.Title;
 
     if (pdfTitle) {
       this.setTitle(pdfTitle + " - " + document.title);

src/core/default_appearance.js

@@ -246,6 +246,8 @@ function createDefaultAppearance({ fontSize, fontName, fontColor }) {
 }
 
 class FakeUnicodeFont {
+  static #fontNameId = 1;
+
   constructor(xref, fontFamily) {
     this.xref = xref;
     this.widths = null;
@@ -256,11 +258,8 @@ class FakeUnicodeFont {
     const canvas = new OffscreenCanvas(1, 1);
     this.ctxMeasure = canvas.getContext("2d", { willReadFrequently: true });
 
-    if (!FakeUnicodeFont._fontNameId) {
-      FakeUnicodeFont._fontNameId = 1;
-    }
     this.fontName = Name.get(
-      `InvalidPDFjsFont_${fontFamily}_${FakeUnicodeFont._fontNameId++}`
+      `InvalidPDFjsFont_${fontFamily}_${FakeUnicodeFont.#fontNameId++}`
     );
   }
 

src/core/jbig2.js

@@ -1677,11 +1677,7 @@ class SimpleSegmentVisitor {
     }
 
     // Combines exported symbols from all referred segments
-    let symbols = this.symbols;
-    if (!symbols) {
-      this.symbols = symbols = {};
-    }
-
+    const symbols = (this.symbols ||= {});
     const inputSymbols = [];
     for (const referredSegment of referredSegments) {
       const referredSymbols = symbols[referredSegment];
@@ -1766,10 +1762,7 @@ class SimpleSegmentVisitor {
   }
 
   onPatternDictionary(dictionary, currentSegment, data, start, end) {
-    let patterns = this.patterns;
-    if (!patterns) {
-      this.patterns = patterns = {};
-    }
+    const patterns = (this.patterns ||= {});
     const decodingContext = new DecodingContext(data, start, end);
     patterns[currentSegment] = decodePatternDictionary(
       dictionary.mmr,
@@ -1811,10 +1804,7 @@ class SimpleSegmentVisitor {
   }
 
   onTables(currentSegment, data, start, end) {
-    let customTables = this.customTables;
-    if (!customTables) {
-      this.customTables = customTables = {};
-    }
+    const customTables = (this.customTables ||= {});
     customTables[currentSegment] = decodeTablesSegment(data, start, end);
   }
 }
@@ -1865,10 +1855,7 @@ class HuffmanTreeNode {
       this.children[bit] = new HuffmanTreeNode(line);
     } else {
       // Create an intermediate node and continue recursively.
-      let node = this.children[bit];
-      if (!node) {
-        this.children[bit] = node = new HuffmanTreeNode(null);
-      }
+      const node = (this.children[bit] ||= new HuffmanTreeNode(null));
       node.buildTree(line, shift - 1);
     }
   }

src/core/xfa/text.js

@@ -110,9 +110,7 @@ class FontSelector {
       "size",
       "letterSpacing",
     ]) {
-      if (!xfaFont[name]) {
-        xfaFont[name] = lastFont.xfaFont[name];
-      }
+      xfaFont[name] ||= lastFont.xfaFont[name];
     }
 
     for (const name of ["top", "bottom", "left", "right"]) {
@@ -127,9 +125,7 @@ class FontSelector {
       lineHeight || lastFont.lineHeight,
       this.fontFinder
     );
-    if (!fontInfo.pdfFont) {
-      fontInfo.pdfFont = lastFont.pdfFont;
-    }
+    fontInfo.pdfFont ||= lastFont.pdfFont;
 
     this.stack.push(fontInfo);
   }

web/internal/canvas_context_details_view.js

@@ -199,9 +199,7 @@ class CanvasContextDetailsView {
       if (type !== "2d") {
         return ctx;
       }
-      if (!wrappedCtx) {
-        wrappedCtx = this.wrapContext(ctx, label);
-      }
+      wrappedCtx ??= this.wrapContext(ctx, label);
       return wrappedCtx;
     };
     return canvas.getContext("2d");