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.

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) {
-      // eslint-disable-next-line no-unsanitized/method
-      return import(moduleName);
-    })
+    ].map(moduleName => import(moduleName)) // eslint-disable-line no-unsanitized/method
   );
 
   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) {
-      return s.stat === "Overall";
-    });
+    rows = rows.filter(s => 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) {
-    return s.length;
-  });
+  const width = labels.map(s => 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) {
-    return new Array(w + 1).join("-");
-  });
+  const hline = width.map(w => 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) {
-      return s.closed;
-    });
+    const allClosed = sessions.every(s => 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) {
-        return loadingTask.destroy();
-      });
+      const destroyPromises = loadingTasks.map(loadingTask =>
+        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) {
-      // eslint-disable-next-line no-unsanitized/method
-      return import(moduleName);
-    })
+    ].map(moduleName => import(moduleName)) // eslint-disable-line no-unsanitized/method
   );
 
   if (isNodeJS) {