Re-factor the PDFDataRangeTransport unit-tests and enable them in Node.js/Travis

There doesn't appear to be any particular reason for only running these unit-tests in browsers, since the `PDFDataRangeTransport` functionality itself should be back-end agnostic.

test/unit/api_spec.js

@@ -1453,99 +1453,87 @@ describe('api', function() {
       }).catch(done.fail);
     });
   });
-  describe('PDFDataRangeTransport', function () {
-    var loadPromise;
-    function getDocumentData() {
-      const pdfPath = new URL('../pdfs/tracemonkey.pdf', window.location).href;
-      if (loadPromise) {
-        return loadPromise;
-      }
-      loadPromise = new Promise(function (resolve, reject) {
-        var xhr = new XMLHttpRequest(pdfPath);
-        xhr.open('GET', pdfPath);
-        xhr.responseType = 'arraybuffer';
-        xhr.onload = function () {
-          resolve(new Uint8Array(xhr.response));
-        };
-        xhr.onerror = function () {
-          reject(new Error('PDF is not loaded'));
-        };
-        xhr.send();
-      });
-      return loadPromise;
-    }
-    it('should fetch document info and page using ranges', function (done) {
-      if (isNodeJS()) {
-        pending('XMLHttpRequest is not supported in Node.js.');
-      }
 
-      var transport;
+  describe('PDFDataRangeTransport', function() {
-      var initialDataLength = 4000;
+    let dataPromise;
-      var fetches = 0;
+
-      var getDocumentPromise = getDocumentData().then(function (data) {
+    beforeAll(function(done) {
-        var initialData = data.subarray(0, initialDataLength);
+      const fileName = 'tracemonkey.pdf';
-        transport = new PDFDataRangeTransport(data.length, initialData);
+      if (isNodeJS()) {
-        transport.requestDataRange = function (begin, end) {
+        dataPromise = NodeFileReaderFactory.fetch({
+          path: TEST_PDFS_PATH.node + fileName,
+        });
+      } else {
+        dataPromise = DOMFileReaderFactory.fetch({
+          path: TEST_PDFS_PATH.dom + fileName,
+        });
+      }
+      done();
+    });
+
+    afterAll(function() {
+      dataPromise = null;
+    });
+
+    it('should fetch document info and page using ranges', function(done) {
+      const initialDataLength = 4000;
+      let fetches = 0, loadingTask;
+
+      dataPromise.then(function(data) {
+        const initialData = data.subarray(0, initialDataLength);
+        const transport = new PDFDataRangeTransport(data.length, initialData);
+        transport.requestDataRange = function(begin, end) {
           fetches++;
-          waitSome(function () {
+          waitSome(function() {
             transport.onDataProgress(4000);
             transport.onDataRange(begin, data.subarray(begin, end));
           });
         };
-        var loadingTask = getDocument(transport);
+        loadingTask = getDocument(transport);
         return loadingTask.promise;
-      });
+      }).then(function(pdfDocument) {
-      var pdfDocument;
-      var getPagePromise = getDocumentPromise.then(function (pdfDocument_) {
-        pdfDocument = pdfDocument_;
-        var pagePromise = pdfDocument.getPage(10);
-        return pagePromise;
-      });
-
-      getPagePromise.then(function (page) {
         expect(pdfDocument.numPages).toEqual(14);
-        expect(page.rotate).toEqual(0);
+
+        return pdfDocument.getPage(10);
+      }).then(function(pdfPage) {
+        expect(pdfPage.rotate).toEqual(0);
         expect(fetches).toBeGreaterThan(2);
-        done();
+
+        loadingTask.destroy().then(done);
       }).catch(done.fail);
     });
-    it('should fetch document info and page using range and streaming',
-        function (done) {
-      if (isNodeJS()) {
-        pending('XMLHttpRequest is not supported in Node.js.');
-      }
 
-      var transport;
+    it('should fetch document info and page using range and streaming',
-      var initialDataLength = 4000;
+        function(done) {
-      var fetches = 0;
+      const initialDataLength = 4000;
-      var getDocumentPromise = getDocumentData().then(function (data) {
+      let fetches = 0, loadingTask;
-        var initialData = data.subarray(0, initialDataLength);
+
-        transport = new PDFDataRangeTransport(data.length, initialData);
+      dataPromise.then(function(data) {
-        transport.requestDataRange = function (begin, end) {
+        const initialData = data.subarray(0, initialDataLength);
+        const transport = new PDFDataRangeTransport(data.length, initialData);
+        transport.requestDataRange = function(begin, end) {
           fetches++;
           if (fetches === 1) {
-            // send rest of the data on first range request.
+            // Send rest of the data on first range request.
             transport.onDataProgressiveRead(data.subarray(initialDataLength));
           }
-          waitSome(function () {
+          waitSome(function() {
             transport.onDataRange(begin, data.subarray(begin, end));
           });
         };
-        var loadingTask = getDocument(transport);
+        loadingTask = getDocument(transport);
         return loadingTask.promise;
-      });
+      }).then(function(pdfDocument) {
-      var pdfDocument;
-      var getPagePromise = getDocumentPromise.then(function (pdfDocument_) {
-        pdfDocument = pdfDocument_;
-        var pagePromise = pdfDocument.getPage(10);
-        return pagePromise;
-      });
-
-      getPagePromise.then(function (page) {
         expect(pdfDocument.numPages).toEqual(14);
-        expect(page.rotate).toEqual(0);
+
+        return pdfDocument.getPage(10);
+      }).then(function(pdfPage) {
+        expect(pdfPage.rotate).toEqual(0);
         expect(fetches).toEqual(1);
-        done();
+
+        waitSome(function() {
+          loadingTask.destroy().then(done);
+        });
       }).catch(done.fail);
     });
   });