Merge pull request #862 from mozilla/i844

fixes #844

app/api.js

@@ -160,6 +160,7 @@ function download(id, keychain, onprogress, canceller) {
         resolve(this.result);
       };
     });
+
     xhr.addEventListener('progress', function(event) {
       if (event.lengthComputable && event.target.status === 200) {
         onprogress([event.loaded, event.total]);
@@ -168,8 +169,10 @@ function download(id, keychain, onprogress, canceller) {
     const auth = await keychain.authHeader();
     xhr.open('get', `/api/download/${id}`);
     xhr.setRequestHeader('Authorization', auth);
+    xhr.setRequestHeader('Connection', 'close');
     xhr.responseType = 'blob';
     xhr.send();
+    onprogress([0, 1]);
   });
 }
 

server/routes/download.js

@@ -14,10 +14,15 @@ module.exports = async function(req, res) {
       'WWW-Authenticate': `send-v1 ${req.nonce}`
     });
     const file_stream = storage.get(id);
-    let sentBytes = 0;
+    let cancelled = false;
-    file_stream.on('data', c => (sentBytes += c.length));
+
-    file_stream.on('end', async () => {
+    req.on('close', () => {
-      if (sentBytes < contentLength) {
+      cancelled = true;
+      file_stream.destroy();
+    });
+
+    file_stream.on('close', async () => {
+      if (cancelled) {
         return;
       }
       const dl = meta.dl + 1;
@@ -32,6 +37,7 @@ module.exports = async function(req, res) {
         log.info('StorageError:', id);
       }
     });
+
     file_stream.pipe(res);
   } catch (e) {
     res.sendStatus(404);

test/frontend/tests/workflow-tests.js

@@ -134,6 +134,27 @@ describe('Upload / Download flow', function() {
     }
   });
 
+  it('can cancel and not increase download count', async function() {
+    const fs = new FileSender(blob);
+    const file = await fs.upload();
+    const fr = new FileReceiver({
+      secretKey: file.toJSON().secretKey,
+      id: file.id,
+      nonce: file.keychain.nonce,
+      requiresPassword: false
+    });
+    await fr.getMetadata();
+    fr.once('progress', () => fr.cancel());
+
+    try {
+      await fr.download(noSave);
+      assert.fail('not cancelled');
+    } catch (e) {
+      await file.updateDownloadCount();
+      assert.equal(file.dtotal, 0);
+    }
+  });
+
   it('can allow multiple downloads', async function() {
     const fs = new FileSender(blob);
     const file = await fs.upload();