Use arrow functions with some Promise.then calls

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

src/core/annotation.js

@@ -1164,9 +1164,7 @@ class Annotation {
       }
 
       const objectLoader = new ObjectLoader(resources, keys, resources.xref);
-      return objectLoader.load().then(function () {
+      return objectLoader.load().then(() => resources);
-        return resources;
-      });
     });
   }
 

src/core/catalog.js

@@ -1475,9 +1475,7 @@ class Catalog {
           if (!found) {
             throw new FormatError("Kid reference not found in parent's kids.");
           }
-          return Promise.all(kidPromises).then(function () {
+          return Promise.all(kidPromises).then(() => [total, parentRef]);
-            return [total, parentRef];
-          });
         });
     }
 

src/core/document.js

@@ -546,9 +546,7 @@ class Page {
           resources: this.resources,
           operatorList: opList,
         })
-        .then(function () {
+        .then(() => opList);
-          return opList;
-        });
     });
 
     // Fetch the page's annotations and add their operator lists to the

src/core/worker.js

@@ -450,9 +450,9 @@ class WorkerMessageHandler {
     });
 
     handler.on("GetPageJSActions", function ({ pageIndex }) {
-      return pdfManager.getPage(pageIndex).then(function (page) {
+      return pdfManager
-        return pdfManager.ensure(page, "jsActions");
+        .getPage(pageIndex)
-      });
+        .then(page => pdfManager.ensure(page, "jsActions"));
     });
 
     handler.on("GetOutline", function (data) {
@@ -479,9 +479,7 @@ class WorkerMessageHandler {
     });
 
     handler.on("GetData", function (data) {
-      return pdfManager.requestLoadedStream().then(function (stream) {
+      return pdfManager.requestLoadedStream().then(stream => stream.bytes);
-        return stream.bytes;
-      });
     });
 
     handler.on("GetAnnotations", function ({ pageIndex, intent }) {
@@ -812,9 +810,9 @@ class WorkerMessageHandler {
     });
 
     handler.on("GetStructTree", function (data) {
-      return pdfManager.getPage(data.pageIndex).then(function (page) {
+      return pdfManager
-        return pdfManager.ensure(page, "getStructTree");
+        .getPage(data.pageIndex)
-      });
+        .then(page => pdfManager.ensure(page, "getStructTree"));
     });
 
     handler.on("FontFallback", function (data) {
@@ -872,9 +870,9 @@ class WorkerMessageHandler {
         return pdfManager.ensureDoc("startXRef");
       });
       handler.on("GetAnnotArray", function (data) {
-        return pdfManager.getPage(data.pageIndex).then(function (page) {
+        return pdfManager
-          return page.annotations.map(a => a.toString());
+          .getPage(data.pageIndex)
-        });
+          .then(page => page.annotations.map(a => a.toString()));
       });
     }
 

test/unit/api_spec.js

@@ -192,9 +192,9 @@ describe("api", function () {
       expect(loadingTask instanceof PDFDocumentLoadingTask).toEqual(true);
       // This can be somewhat random -- we cannot guarantee perfect
       // 'Terminate' message to the worker before/after setting up pdfManager.
-      const destroyed = loadingTask._worker.promise.then(function () {
+      const destroyed = loadingTask._worker.promise.then(() =>
-        return loadingTask.destroy();
+        loadingTask.destroy()
-      });
+      );
 
       await destroyed;
       expect(true).toEqual(true);
@@ -861,9 +861,9 @@ describe("api", function () {
         expect(!!worker).toEqual(true);
       });
 
-      const destroyPromise = loadingTask.promise.then(function () {
+      const destroyPromise = loadingTask.promise.then(() =>
-        return loadingTask.destroy();
+        loadingTask.destroy()
-      });
+      );
       await destroyPromise;
 
       const destroyedWorker = loadingTask._worker;
@@ -890,9 +890,9 @@ describe("api", function () {
         expect(messageHandlerPort === worker.port).toEqual(true);
       });
 
-      const destroyPromise = loadingTask.promise.then(function () {
+      const destroyPromise = loadingTask.promise.then(() =>
-        return loadingTask.destroy();
+        loadingTask.destroy()
-      });
+      );
       await destroyPromise;
 
       expect(worker.destroyed).toEqual(false);
@@ -1141,8 +1141,8 @@ describe("api", function () {
         buildGetDocumentParams("Pages-tree-refs.pdf")
       );
 
-      const page1 = loadingTask.promise.then(function (pdfDoc) {
+      const page1 = loadingTask.promise.then(pdfDoc =>
-        return pdfDoc.getPage(1).then(
+        pdfDoc.getPage(1).then(
           function (pdfPage) {
             expect(pdfPage instanceof PDFPageProxy).toEqual(true);
             expect(pdfPage.ref).toEqual({ num: 6, gen: 0 });
@@ -1150,11 +1150,11 @@ describe("api", function () {
           function (reason) {
             throw new Error("shall not fail for valid page");
           }
+        )
       );
-      });
 
-      const page2 = loadingTask.promise.then(function (pdfDoc) {
+      const page2 = loadingTask.promise.then(pdfDoc =>
-        return pdfDoc.getPage(2).then(
+        pdfDoc.getPage(2).then(
           function (pdfPage) {
             throw new Error("shall fail for invalid page");
           },
@@ -1164,8 +1164,8 @@ describe("api", function () {
               "Pages tree contains circular reference."
             );
           }
+        )
       );
-      });
 
       await Promise.all([page1, page2]);
       await loadingTask.destroy();
@@ -1396,29 +1396,29 @@ describe("api", function () {
     it("gets page labels", async function () {
       // PageLabels with Roman/Arabic numerals.
       const loadingTask0 = getDocument(buildGetDocumentParams("bug793632.pdf"));
-      const promise0 = loadingTask0.promise.then(function (pdfDoc) {
+      const promise0 = loadingTask0.promise.then(pdfDoc =>
-        return pdfDoc.getPageLabels();
+        pdfDoc.getPageLabels()
-      });
+      );
 
       // PageLabels with only a label prefix.
       const loadingTask1 = getDocument(buildGetDocumentParams("issue1453.pdf"));
-      const promise1 = loadingTask1.promise.then(function (pdfDoc) {
+      const promise1 = loadingTask1.promise.then(pdfDoc =>
-        return pdfDoc.getPageLabels();
+        pdfDoc.getPageLabels()
-      });
+      );
 
       // PageLabels identical to standard page numbering.
       const loadingTask2 = getDocument(buildGetDocumentParams("rotation.pdf"));
-      const promise2 = loadingTask2.promise.then(function (pdfDoc) {
+      const promise2 = loadingTask2.promise.then(pdfDoc =>
-        return pdfDoc.getPageLabels();
+        pdfDoc.getPageLabels()
-      });
+      );
 
       // PageLabels with bad "Prefix" entries.
       const loadingTask3 = getDocument(
         buildGetDocumentParams("bad-PageLabels.pdf")
       );
-      const promise3 = loadingTask3.promise.then(function (pdfDoc) {
+      const promise3 = loadingTask3.promise.then(pdfDoc =>
-        return pdfDoc.getPageLabels();
+        pdfDoc.getPageLabels()
-      });
+      );
 
       const pageLabels = await Promise.all([
         promise0,
@@ -1512,9 +1512,7 @@ describe("api", function () {
       );
 
       const promise1 = loadingTask1.promise
-        .then(function (pdfDoc) {
+        .then(pdfDoc => pdfDoc.getOpenAction())
-          return pdfDoc.getOpenAction();
-        })
         .then(function (openAction) {
           expect(openAction.dest).toBeUndefined();
           expect(openAction.action).toEqual("Print");
@@ -1522,9 +1520,7 @@ describe("api", function () {
           return loadingTask1.destroy();
         });
       const promise2 = loadingTask2.promise
-        .then(function (pdfDoc) {
+        .then(pdfDoc => pdfDoc.getOpenAction())
-          return pdfDoc.getOpenAction();
-        })
         .then(function (openAction) {
           expect(openAction.dest).toBeUndefined();
           expect(openAction.action).toEqual("Print");
@@ -2064,25 +2060,25 @@ describe("api", function () {
       const loadingTask0 = getDocument(
         buildGetDocumentParams("issue9972-1.pdf")
       );
-      const promise0 = loadingTask0.promise.then(function (pdfDoc) {
+      const promise0 = loadingTask0.promise.then(pdfDoc =>
-        return pdfDoc.getPermissions();
+        pdfDoc.getPermissions()
-      });
+      );
 
       // Printing not allowed.
       const loadingTask1 = getDocument(
         buildGetDocumentParams("issue9972-2.pdf")
       );
-      const promise1 = loadingTask1.promise.then(function (pdfDoc) {
+      const promise1 = loadingTask1.promise.then(pdfDoc =>
-        return pdfDoc.getPermissions();
+        pdfDoc.getPermissions()
-      });
+      );
 
       // Copying not allowed.
       const loadingTask2 = getDocument(
         buildGetDocumentParams("issue9972-3.pdf")
       );
-      const promise2 = loadingTask2.promise.then(function (pdfDoc) {
+      const promise2 = loadingTask2.promise.then(pdfDoc =>
-        return pdfDoc.getPermissions();
+        pdfDoc.getPermissions()
-      });
+      );
 
       const totalPermissionCount = Object.keys(PermissionFlag).length;
       const permissions = await Promise.all([promise0, promise1, promise2]);
@@ -3050,9 +3046,7 @@ describe("api", function () {
         params.url = url.href;
         loadingTask = getDocument(params);
         return loadingTask.promise
-          .then(function (pdf) {
+          .then(pdf => pdf.destroy())
-            return pdf.destroy();
-          })
           .then(
             function () {
               expect(expectSuccess).toEqual(true);
@@ -3293,11 +3287,10 @@ describe("api", function () {
       const filename = "bug766086.pdf";
 
       const defaultLoadingTask = getDocument(buildGetDocumentParams(filename));
-      const defaultPromise = defaultLoadingTask.promise.then(function (pdfDoc) {
+      const defaultPromise = defaultLoadingTask.promise.then(async pdfDoc => {
-        return pdfDoc.getPage(1).then(function (pdfPage) {
+        const pdfPage = await pdfDoc.getPage(1);
         return pdfPage.getAnnotations();
       });
-      });
 
       const docBaseUrlLoadingTask = getDocument(
         buildGetDocumentParams(filename, {
@@ -3305,10 +3298,9 @@ describe("api", function () {
         })
       );
       const docBaseUrlPromise = docBaseUrlLoadingTask.promise.then(
-        function (pdfDoc) {
+        async pdfDoc => {
-          return pdfDoc.getPage(1).then(function (pdfPage) {
+          const pdfPage = await pdfDoc.getPage(1);
           return pdfPage.getAnnotations();
-          });
         }
       );
 
@@ -3318,11 +3310,10 @@ describe("api", function () {
         })
       );
       const invalidDocBaseUrlPromise =
-        invalidDocBaseUrlLoadingTask.promise.then(function (pdfDoc) {
+        invalidDocBaseUrlLoadingTask.promise.then(async pdfDoc => {
-          return pdfDoc.getPage(1).then(function (pdfPage) {
+          const pdfPage = await pdfDoc.getPage(1);
           return pdfPage.getAnnotations();
         });
-        });
 
       const [
         defaultAnnotations,