Use arrow function with various Array methods

A lot of this is quite old code, which we can shorten slightly by using arrow functions instead of "regular" functions.

src/core/chunked_stream.js

@@ -414,9 +414,7 @@ class ChunkedStreamManager {
       }
     }
 
-    chunksToRequest.sort(function (a, b) {
+    chunksToRequest.sort((a, b) => a - b);
-      return a - b;
-    });
     return this._requestChunks(chunksToRequest);
   }
 

src/core/fonts.js

@@ -576,9 +576,7 @@ function getRanges(glyphs, toUnicodeExtraMap, numGlyphs) {
   if (codes.length === 0) {
     codes.push({ fontCharCode: 0, glyphId: 0 });
   }
-  codes.sort(function fontGetRangesSort(a, b) {
+  codes.sort((a, b) => a.fontCharCode - b.fontCharCode);
-    return a.fontCharCode - b.fontCharCode;
-  });
 
   // Split the sorted codes into ranges.
   const ranges = [];
@@ -1777,9 +1775,7 @@ class Font {
       }
 
       // removing duplicate entries
-      mappings.sort(function (a, b) {
+      mappings.sort((a, b) => a.charCode - b.charCode);
-        return a.charCode - b.charCode;
-      });
       const finalMappings = [],
         seenCharCodes = new Set();
       for (const map of mappings) {

src/core/jbig2.js

@@ -374,9 +374,7 @@ function decodeBitmap(
   // Sorting is non-standard, and it is not required. But sorting increases
   // the number of template bits that can be reused from the previous
   // contextLabel in the main loop.
-  template.sort(function (a, b) {
+  template.sort((a, b) => a.y - b.y || a.x - b.x);
-    return a.y - b.y || a.x - b.x;
-  });
 
   const templateLength = template.length;
   const templateX = new Int8Array(templateLength);

src/core/xml_parser.js

@@ -321,11 +321,7 @@ class SimpleDOMNode {
     if (!this.childNodes) {
       return this.nodeValue || "";
     }
-    return this.childNodes
+    return this.childNodes.map(child => child.textContent).join("");
-      .map(function (child) {
-        return child.textContent;
-      })
-      .join("");
   }
 
   get children() {

test/font/jasmine-boot.js

@@ -49,10 +49,7 @@ async function initializePDFJS(callback) {
       "pdfjs-test/font/font_os2_spec.js",
       "pdfjs-test/font/font_post_spec.js",
       "pdfjs-test/font/font_fpgm_spec.js",
-    ].map(function (moduleName) {
+    ].map(moduleName => import(moduleName)) // eslint-disable-line no-unsanitized/method
-      // eslint-disable-next-line no-unsanitized/method
-      return import(moduleName);
-    })
   );
 
   callback();

test/stats/statcmp.js

@@ -64,9 +64,7 @@ function flatten(stats) {
   });
   // Use only overall results if not grouped by 'stat'
   if (!options.groupBy.includes("stat")) {
-    rows = rows.filter(function (s) {
+    rows = rows.filter(s => s.stat === "Overall");
-      return s.stat === "Overall";
-    });
   }
   return rows;
 }
@@ -129,9 +127,7 @@ function stat(baseline, current) {
   }
   const rows = [];
   // collect rows and measure column widths
-  const width = labels.map(function (s) {
+  const width = labels.map(s => s.length);
-    return s.length;
-  });
   rows.push(labels);
   for (const key of keys) {
     const baselineMean = mean(baselineGroup[key]);
@@ -162,9 +158,7 @@ function stat(baseline, current) {
   }
 
   // add horizontal line
-  const hline = width.map(function (w) {
+  const hline = width.map(w => new Array(w + 1).join("-"));
-    return new Array(w + 1).join("-");
-  });
   rows.splice(1, 0, hline);
 
   // print output

test/test.mjs

@@ -1051,9 +1051,7 @@ async function closeSession(browser) {
       await session.browser.close();
     }
     session.closed = true;
-    const allClosed = sessions.every(function (s) {
+    const allClosed = sessions.every(s => s.closed);
-      return s.closed;
-    });
     if (allClosed) {
       if (tempDir) {
         fs.rmSync(tempDir, { recursive: true, force: true });

test/unit/api_spec.js

@@ -4869,9 +4869,9 @@ Caron Broadcasting, Inc., an Ohio corporation (“Lessee”).`)
       // Issue 6205 reported an issue with font rendering, so clear the loaded
       // fonts so that we can see whether loading PDFs in parallel does not
       // cause any issues with the rendered fonts.
-      const destroyPromises = loadingTasks.map(function (loadingTask) {
+      const destroyPromises = loadingTasks.map(loadingTask =>
-        return loadingTask.destroy();
+        loadingTask.destroy()
-      });
+      );
       await Promise.all(destroyPromises);
     });
 

test/unit/jasmine-boot.js

@@ -100,10 +100,7 @@ async function initializePDFJS(callback) {
       "pdfjs-test/unit/xfa_serialize_data_spec.js",
       "pdfjs-test/unit/xfa_tohtml_spec.js",
       "pdfjs-test/unit/xml_spec.js",
-    ].map(function (moduleName) {
+    ].map(moduleName => import(moduleName)) // eslint-disable-line no-unsanitized/method
-      // eslint-disable-next-line no-unsanitized/method
-      return import(moduleName);
-    })
   );
 
   if (isNodeJS) {

web/debugger.mjs

@@ -398,9 +398,7 @@ class Stepper {
   }
 
   getNextBreakPoint() {
-    this.breakPoints.sort(function (a, b) {
+    this.breakPoints.sort((a, b) => a - b);
-      return a - b;
-    });
     for (const breakPoint of this.breakPoints) {
       if (breakPoint > this.currentIdx) {
         return breakPoint;
@@ -487,9 +485,7 @@ const Stats = (function Stats() {
       statsDiv.textContent = stat.toString();
       wrapper.append(title, statsDiv);
       stats.push({ pageNumber, div: wrapper });
-      stats.sort(function (a, b) {
+      stats.sort((a, b) => a.pageNumber - b.pageNumber);
-        return a.pageNumber - b.pageNumber;
-      });
       clear(this.panel);
       for (const entry of stats) {
         this.panel.append(entry.div);