Test for Firefox download disconnecting push channel

Change-Id: Iacf2b04b96c237ad377dbd75ad07f86a00660319

uitest/src/main/java/com/vaadin/tests/resources/DownloadWithPush.java

@@ -0,0 +1,94 @@
+package com.vaadin.tests.resources;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import com.vaadin.annotations.Push;
+import com.vaadin.server.DownloadStream;
+import com.vaadin.server.Resource;
+import com.vaadin.server.StreamResource;
+import com.vaadin.server.StreamResource.StreamSource;
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.tests.components.AbstractTestUIWithLog;
+import com.vaadin.ui.Button;
+import com.vaadin.ui.Button.ClickEvent;
+
+@Push
+public class DownloadWithPush extends AbstractTestUIWithLog {
+
+    private static class GeneratedStream extends InputStream {
+        int read = 0;
+        int next = 'a';
+        private final int size;
+
+        public GeneratedStream(int size) {
+            this.size = size;
+        }
+
+        @Override
+        public int read() throws IOException {
+            if (available() == 0) {
+                return -1;
+            }
+
+            read++;
+            next++;
+            if (next > 'z') {
+                next = 'a';
+            }
+            return next;
+        }
+
+        @Override
+        public int available() throws IOException {
+            return size - read;
+        }
+    }
+
+    private final class DownloadResoure extends StreamResource {
+        private DownloadResoure(StreamSource streamSource, String filename) {
+            super(streamSource, filename);
+        }
+
+        @Override
+        public DownloadStream getStream() {
+            DownloadStream ds = super.getStream();
+            ds.setParameter("Content-Disposition",
+                    "attachment; filename=" + getFilename() + ";");
+            return ds;
+        }
+    }
+
+    private Resource hugeFileResource = createResource();;
+    private int fileSize = 300 * (1024 * 1024);
+
+    @Override
+    protected void setup(VaadinRequest request) {
+        Button b = new Button("Download a "
+                + String.format("%.1f", fileSize / 1024.0 / 1024.0) + "MB file",
+                new Button.ClickListener() {
+                    @Override
+                    public void buttonClick(ClickEvent event) {
+                        getUI().getPage().open(hugeFileResource, "", false);
+                    }
+                });
+        addComponent(b);
+    }
+
+    private Resource createResource() {
+        Resource hugeFileResource = new DownloadResoure(new StreamSource() {
+            @Override
+            public InputStream getStream() {
+                return new GeneratedStream(fileSize);
+            }
+        }, "hugefile.txt");
+        return hugeFileResource;
+    }
+
+
+    @Override
+    protected Integer getTicketNumber() {
+        return 19709;
+    }
+
+}