Use shorter arrow functions where possible

For arrow functions that are both simple and short, we can avoid using explicit `return` to shorten them even further without hurting readability.

For the `gulp mozcentral` build-target this reduces the overall size of the output by just under 1 kilo-byte (which isn't a lot but still can't hurt).

src/core/annotation.js

@@ -4824,9 +4824,7 @@ class StampAnnotation extends MarkupAnnotation {
 
     const jpegBufferPromise = canvas
       .convertToBlob({ type: "image/jpeg", quality: 1 })
-      .then(blob => {
+      .then(blob => blob.arrayBuffer());
-        return blob.arrayBuffer();
-      });
 
     const xobjectName = Name.get("XObject");
     const imageName = Name.get("Image");

src/core/cmap.js

@@ -691,9 +691,9 @@ async function createBuiltInCMap(name, fetchBuiltInCMap) {
   const cMap = new CMap(true);
 
   if (compressionType === CMapCompressionType.BINARY) {
-    return new BinaryCMapReader().process(cMapData, cMap, useCMap => {
+    return new BinaryCMapReader().process(cMapData, cMap, useCMap =>
-      return extendCMap(cMap, fetchBuiltInCMap, useCMap);
+      extendCMap(cMap, fetchBuiltInCMap, useCMap)
-    });
+    );
   }
   if (compressionType === CMapCompressionType.NONE) {
     const lexer = new Lexer(new Stream(cMapData));

src/core/fonts.js

@@ -2093,9 +2093,7 @@ class Font {
           endOffset: 0,
         });
       }
-      locaEntries.sort((a, b) => {
+      locaEntries.sort((a, b) => a.offset - b.offset);
-        return a.offset - b.offset;
-      });
       // Now the offsets are sorted, calculate the end offset of each glyph.
       // The last loca entry's endOffset is not calculated since it's the end
       // of the data and will be stored on the previous entry's endOffset.
@@ -2103,9 +2101,7 @@ class Font {
         locaEntries[i].endOffset = locaEntries[i + 1].offset;
       }
       // Re-sort so glyphs aren't out of order.
-      locaEntries.sort((a, b) => {
+      locaEntries.sort((a, b) => a.index - b.index);
-        return a.index - b.index;
-      });
       // Calculate the endOffset of the "first" glyph correctly when there are
       // *multiple* empty ones at the start of the data (fixes issue14618.pdf).
       for (i = 0; i < numGlyphs; i++) {

src/core/writer.js

@@ -344,10 +344,9 @@ async function incrementalUpdate({
 
   // Add a ref for the new xref and sort them
   newRefs.push({ ref: refForXrefTable, data: "" });
-  newRefs = newRefs.sort((a, b) => {
+  newRefs = newRefs.sort(
-    // compare the refs
+    (a, b) => /* compare the refs */ a.ref.num - b.ref.num
-    return a.ref.num - b.ref.num;
+  );
-  });
 
   const xrefTableData = [[0, 1, 0xffff]];
   const indexes = [0, 1];

src/display/api.js

@@ -771,19 +771,13 @@ class PDFDocumentProxy {
     if (typeof PDFJSDev === "undefined" || PDFJSDev.test("TESTING")) {
       // For testing purposes.
       Object.defineProperty(this, "getXFADatasets", {
-        value: () => {
+        value: () => this._transport.getXFADatasets(),
-          return this._transport.getXFADatasets();
-        },
       });
       Object.defineProperty(this, "getXRefPrevValue", {
-        value: () => {
+        value: () => this._transport.getXRefPrevValue(),
-          return this._transport.getXRefPrevValue();
-        },
       });
       Object.defineProperty(this, "getAnnotArray", {
-        value: pageIndex => {
+        value: pageIndex => this._transport.getAnnotArray(pageIndex),
-          return this._transport.getAnnotArray(pageIndex);
-        },
       });
     }
   }
@@ -1628,9 +1622,7 @@ class PDFPageProxy {
     if (this._transport._htmlForXfa) {
       // TODO: We need to revisit this once the XFA foreground patch lands and
       // only do this for non-foreground XFA.
-      return this.getXfa().then(xfa => {
+      return this.getXfa().then(xfa => XfaText.textContent(xfa));
-        return XfaText.textContent(xfa);
-      });
     }
     const readableStream = this.streamTextContent(params);
 
@@ -2358,21 +2350,16 @@ class WorkerTransport {
     if (typeof PDFJSDev === "undefined" || PDFJSDev.test("TESTING")) {
       // For testing purposes.
       Object.defineProperty(this, "getXFADatasets", {
-        value: () => {
+        value: () =>
-          return this.messageHandler.sendWithPromise("GetXFADatasets", null);
+          this.messageHandler.sendWithPromise("GetXFADatasets", null),
-        },
       });
       Object.defineProperty(this, "getXRefPrevValue", {
-        value: () => {
+        value: () =>
-          return this.messageHandler.sendWithPromise("GetXRefPrevValue", null);
+          this.messageHandler.sendWithPromise("GetXRefPrevValue", null),
-        },
       });
       Object.defineProperty(this, "getAnnotArray", {
-        value: pageIndex => {
+        value: pageIndex =>
-          return this.messageHandler.sendWithPromise("GetAnnotArray", {
+          this.messageHandler.sendWithPromise("GetAnnotArray", { pageIndex }),
-            pageIndex,
-          });
-        },
       });
     }
   }
@@ -2737,9 +2724,7 @@ class WorkerTransport {
 
           this.fontLoader
             .bind(font)
-            .catch(reason => {
+            .catch(() => messageHandler.sendWithPromise("FontFallback", { id }))
-              return messageHandler.sendWithPromise("FontFallback", { id });
-            })
             .finally(() => {
               if (!params.fontExtraProperties && font.data) {
                 // Immediately release the `font.data` property once the font
@@ -3013,9 +2998,7 @@ class WorkerTransport {
   getOptionalContentConfig() {
     return this.messageHandler
       .sendWithPromise("GetOptionalContentConfig", null)
-      .then(results => {
+      .then(results => new OptionalContentConfig(results));
-        return new OptionalContentConfig(results);
-      });
   }
 
   getPermissions() {
@@ -3192,9 +3175,7 @@ class RenderTask {
     if (typeof PDFJSDev === "undefined" || PDFJSDev.test("TESTING")) {
       // For testing purposes.
       Object.defineProperty(this, "getOperatorList", {
-        value: () => {
+        value: () => this.#internalRenderTask.operatorList,
-          return this.#internalRenderTask.operatorList;
-        },
       });
     }
   }

src/display/display_utils.js

@@ -483,9 +483,9 @@ class DOMStandardFontDataFactory extends BaseStandardFontDataFactory {
    * @ignore
    */
   _fetchData(url) {
-    return fetchData(url, /* type = */ "arraybuffer").then(data => {
+    return fetchData(url, /* type = */ "arraybuffer").then(
-      return new Uint8Array(data);
+      data => new Uint8Array(data)
-    });
+    );
   }
 }
 

src/display/fetch_stream.js

@@ -147,9 +147,8 @@ class PDFFetchStreamReader {
         this._reader = response.body.getReader();
         this._headersCapability.resolve();
 
-        const getResponseHeader = name => {
+        const getResponseHeader = name => response.headers.get(name);
-          return response.headers.get(name);
+
-        };
         const { allowRangeRequests, suggestedLength } =
           validateRangeRequestCapabilities({
             getResponseHeader,

src/display/network.js

@@ -279,9 +279,8 @@ class PDFNetworkStreamFullRequestReader {
     const fullRequestXhrId = this._fullRequestId;
     const fullRequestXhr = this._manager.getRequestXhr(fullRequestXhrId);
 
-    const getResponseHeader = name => {
+    const getResponseHeader = name => fullRequestXhr.getResponseHeader(name);
-      return fullRequestXhr.getResponseHeader(name);
+
-    };
     const { allowRangeRequests, suggestedLength } =
       validateRangeRequestCapabilities({
         getResponseHeader,

src/display/node_stream.js

@@ -326,11 +326,11 @@ class PDFNodeStreamFullReader extends BaseFullReader {
       this._headersCapability.resolve();
       this._setReadableStream(response);
 
-      const getResponseHeader = name => {
+      // Make sure that headers name are in lower case, as mentioned
-        // Make sure that headers name are in lower case, as mentioned
+      // here: https://nodejs.org/api/http.html#http_message_headers.
-        // here: https://nodejs.org/api/http.html#http_message_headers.
+      const getResponseHeader = name =>
-        return this._readableStream.headers[name.toLowerCase()];
+        this._readableStream.headers[name.toLowerCase()];
-      };
+
       const { allowRangeRequests, suggestedLength } =
         validateRangeRequestCapabilities({
           getResponseHeader,

src/pdf.sandbox.js

@@ -141,9 +141,7 @@ class Sandbox {
 }
 
 function QuickJSSandbox() {
-  return ModuleLoader().then(module => {
+  return ModuleLoader().then(module => new Sandbox(window, module));
-    return new Sandbox(window, module);
-  });
 }
 
 export { QuickJSSandbox };

src/scripting_api/util.js

@@ -212,66 +212,26 @@ class Util extends PDFObject {
     }
 
     const handlers = {
-      mmmm: data => {
+      mmmm: data => this._months[data.month],
-        return this._months[data.month];
+      mmm: data => this._months[data.month].substring(0, 3),
-      },
+      mm: data => (data.month + 1).toString().padStart(2, "0"),
-      mmm: data => {
+      m: data => (data.month + 1).toString(),
-        return this._months[data.month].substring(0, 3);
+      dddd: data => this._days[data.dayOfWeek],
-      },
+      ddd: data => this._days[data.dayOfWeek].substring(0, 3),
-      mm: data => {
+      dd: data => data.day.toString().padStart(2, "0"),
-        return (data.month + 1).toString().padStart(2, "0");
+      d: data => data.day.toString(),
-      },
+      yyyy: data => data.year.toString(),
-      m: data => {
+      yy: data => (data.year % 100).toString().padStart(2, "0"),
-        return (data.month + 1).toString();
+      HH: data => data.hours.toString().padStart(2, "0"),
-      },
+      H: data => data.hours.toString(),
-      dddd: data => {
+      hh: data => (1 + ((data.hours + 11) % 12)).toString().padStart(2, "0"),
-        return this._days[data.dayOfWeek];
+      h: data => (1 + ((data.hours + 11) % 12)).toString(),
-      },
+      MM: data => data.minutes.toString().padStart(2, "0"),
-      ddd: data => {
+      M: data => data.minutes.toString(),
-        return this._days[data.dayOfWeek].substring(0, 3);
+      ss: data => data.seconds.toString().padStart(2, "0"),
-      },
+      s: data => data.seconds.toString(),
-      dd: data => {
+      tt: data => (data.hours < 12 ? "am" : "pm"),
-        return data.day.toString().padStart(2, "0");
+      t: data => (data.hours < 12 ? "a" : "p"),
-      },
-      d: data => {
-        return data.day.toString();
-      },
-      yyyy: data => {
-        return data.year.toString();
-      },
-      yy: data => {
-        return (data.year % 100).toString().padStart(2, "0");
-      },
-      HH: data => {
-        return data.hours.toString().padStart(2, "0");
-      },
-      H: data => {
-        return data.hours.toString();
-      },
-      hh: data => {
-        return (1 + ((data.hours + 11) % 12)).toString().padStart(2, "0");
-      },
-      h: data => {
-        return (1 + ((data.hours + 11) % 12)).toString();
-      },
-      MM: data => {
-        return data.minutes.toString().padStart(2, "0");
-      },
-      M: data => {
-        return data.minutes.toString();
-      },
-      ss: data => {
-        return data.seconds.toString().padStart(2, "0");
-      },
-      s: data => {
-        return data.seconds.toString();
-      },
-      tt: data => {
-        return data.hours < 12 ? "am" : "pm";
-      },
-      t: data => {
-        return data.hours < 12 ? "a" : "p";
-      },
     };
 
     const data = {

test/integration/freetext_editor_spec.mjs

@@ -237,9 +237,10 @@ describe("FreeText Editor", () => {
           await clearAll(page);
 
           for (const n of [0, 1, 2]) {
-            const hasEditor = await page.evaluate(sel => {
+            const hasEditor = await page.evaluate(
-              return !!document.querySelector(sel);
+              sel => !!document.querySelector(sel),
-            }, getEditorSelector(n));
+              getEditorSelector(n)
+            );
 
             expect(hasEditor).withContext(`In ${browserName}`).toEqual(false);
           }

test/unit/api_spec.js

@@ -942,14 +942,10 @@ describe("api", function () {
       );
 
       const loadingTask1 = getDocument(basicApiGetDocumentParams);
-      const promise1 = loadingTask1.promise.then(pdfDoc => {
+      const promise1 = loadingTask1.promise.then(pdfDoc => pdfDoc.numPages);
-        return pdfDoc.numPages;
-      });
 
       const loadingTask2 = getDocument(tracemonkeyGetDocumentParams);
-      const promise2 = loadingTask2.promise.then(pdfDoc => {
+      const promise2 = loadingTask2.promise.then(pdfDoc => pdfDoc.numPages);
-        return pdfDoc.numPages;
-      });
 
       const [numPages1, numPages2] = await Promise.all([promise1, promise2]);
       expect(numPages1).toEqual(3);
@@ -3901,9 +3897,9 @@ Caron Broadcasting, Inc., an Ohio corporation (“Lessee”).`)
             true
           );
           expect(
-            currentImgData.data.every((value, index) => {
+            currentImgData.data.every(
-              return value === firstImgData.data[index];
+              (value, index) => value === firstImgData.data[index]
-            })
+            )
           ).toEqual(true);
 
           if (i === NUM_PAGES_THRESHOLD) {

test/unit/cff_parser_spec.js

@@ -377,9 +377,7 @@ describe("CFFCompiler", function () {
     bytes = new Uint8Array(bytes);
     return new CFFParser(
       {
-        getBytes: () => {
+        getBytes: () => bytes,
-          return bytes;
-        },
       },
       {},
       SEAC_ANALYSIS_ENABLED

test/unit/message_handler_spec.js

@@ -24,9 +24,7 @@ import { MessageHandler } from "../../src/shared/message_handler.js";
 describe("message_handler", function () {
   // Sleep function to wait for sometime, similar to setTimeout but faster.
   function sleep(ticks) {
-    return Promise.resolve().then(() => {
+    return Promise.resolve().then(() => ticks && sleep(ticks - 1));
-      return ticks && sleep(ticks - 1);
-    });
   }
 
   describe("sendWithStream", function () {

test/unit/node_stream_spec.js

@@ -62,9 +62,7 @@ describe("node_stream", function () {
             const [start, end] = request.headers.range
               .split("=")[1]
               .split("-")
-              .map(x => {
+              .map(x => Number(x));
-                return Number(x);
-              });
             const stream = fs.createReadStream(filePath, { start, end });
             response.writeHead(206, {
               "Content-Type": "application/pdf",

test/unit/pdf_find_controller_spec.js

@@ -121,9 +121,7 @@ function testSearch({
       }
     }
 
-    const totalMatches = matchesPerPage.reduce((a, b) => {
+    const totalMatches = matchesPerPage.reduce((a, b) => a + b);
-      return a + b;
-    });
 
     if (updateFindControlState) {
       eventBus.on(

test/unit/scripting_spec.js

@@ -52,9 +52,9 @@ describe("Scripting", function () {
       send_queue.set(command, { command, value });
     };
     // eslint-disable-next-line no-unsanitized/method
-    const promise = import(sandboxBundleSrc).then(pdfjsSandbox => {
+    const promise = import(sandboxBundleSrc).then(pdfjsSandbox =>
-      return pdfjsSandbox.QuickJSSandbox();
+      pdfjsSandbox.QuickJSSandbox()
-    });
+    );
     sandbox = {
       createSandbox(data) {
         promise.then(sbx => sbx.create(data));

web/app.js

@@ -1764,9 +1764,7 @@ const PDFViewerApplication = {
       .catch(() => {
         /* Avoid breaking printing; ignoring errors. */
       })
-      .then(() => {
+      .then(() => this.pdfDocument?.annotationStorage.print);
-        return this.pdfDocument?.annotationStorage.print;
-      });
 
     if (this.printService) {
       // There is no way to suppress beforePrint/afterPrint events,

web/pdf_link_service.js

@@ -54,9 +54,7 @@ function addLinkAttributes(link, { url, target, rel, enabled = true } = {}) {
   } else {
     link.href = "";
     link.title = `Disabled: ${url}`;
-    link.onclick = () => {
+    link.onclick = () => false;
-      return false;
-    };
   }
 
   let targetStr = ""; // LinkTarget.NONE

web/pdf_scripting_manager.component.js

@@ -30,13 +30,9 @@ class PDFScriptingManagerComponents extends PDFScriptingManager {
     }
 
     options.externalServices ||= {
-      createScripting: () => {
+      createScripting: () => new GenericScripting(options.sandboxBundleSrc),
-        return new GenericScripting(options.sandboxBundleSrc);
-      },
-    };
-    options.docProperties ||= pdfDocument => {
-      return docProperties(pdfDocument);
     };
+    options.docProperties ||= pdfDocument => docProperties(pdfDocument);
     super(options);
   }
 }

web/ui_utils.js

@@ -206,20 +206,18 @@ function parseQueryString(query) {
   return params;
 }
 
-const InvisibleCharactersRegExp = /[\x00-\x1F]/g;
+const InvisibleCharsRegExp = /[\x00-\x1F]/g;
 
 /**
  * @param {string} str
  * @param {boolean} [replaceInvisible]
  */
 function removeNullCharacters(str, replaceInvisible = false) {
-  if (!InvisibleCharactersRegExp.test(str)) {
+  if (!InvisibleCharsRegExp.test(str)) {
     return str;
   }
   if (replaceInvisible) {
-    return str.replaceAll(InvisibleCharactersRegExp, m => {
+    return str.replaceAll(InvisibleCharsRegExp, m => (m === "\x00" ? "" : " "));
-      return m === "\x00" ? "" : " ";
-    });
   }
   return str.replaceAll("\x00", "");
 }