CODEWITHSUNDEEP
pythongoogle-app-engine
Khoi
Khoi

Reputation: 4635

GAE - how to use blobstore stub in testbed?

My code goes like this:

self.testbed.init_blobstore_stub()
upload_url = blobstore.create_upload_url('/image')
upload_url = re.sub('^http://testbed\.example\.com', '', upload_url)

response = self.testapp.post(upload_url, params={
    'shopid': id,
    'description': 'JLo',
    }, upload_files=[('file', imgPath)])
self.assertEqual(response.status_int, 200)

how come it shows 404 error? For some reasons the upload path does not seem to exist at all.

Upvotes: 1

Views: 669

Answers (2)

Julien
Julien

Reputation: 934

I think Kekito is right, you cannot POST to the upload_url directly.

But if you want to test the BlobstoreUploadHandler, you can fake the POST request it would normally received from the blobstore in the following way. Assuming your handler is at /handler :

    import email
    ...

    def test_upload(self):
        blob_key = 'abcd'
        # The blobstore upload handler receives a multipart form request
        # containing uploaded files. But instead of containing the actual
        # content, the files contain an 'email' message that has some meta
        # information about the file. They also contain a blob-key that is
        # the key to get the blob from the blobstore

        # see blobstore._get_upload_content
        m = email.message.Message()
        m.add_header('Content-Type', 'image/png')
        m.add_header('Content-Length', '100')
        m.add_header('X-AppEngine-Upload-Creation', '2014-03-02 23:04:05.123456')
        # This needs to be valie base64 encoded
        m.add_header('content-md5', 'd74682ee47c3fffd5dcd749f840fcdd4')
        payload = m.as_string()
        # The blob-key in the Content-type is important
        params = [('file', webtest.forms.Upload('test.png', payload,
                                                'image/png; blob-key='+blob_key))]

        self.testapp.post('/handler', params, content_type='blob-key')

I figured that out by digging into the blobstore code. The important bit is that the POST request that the blobstore sends to the UploadHandler doesn't contain the file content. Instead, it contains an "email message" (well, informations encoded like in an email) with metadata about the file (content-type, content-length, upload time and md5). It also contains a blob-key that can be used to retrieve the file from the blobstore.

Upvotes: 2

minou
minou

Reputation: 16563

You can't do this. I think the problem is that webtest (which I assume is where self.testapp came from) doesn't work well with testbed blobstore functionality. You can find some info at this question.

My solution was to override unittest.TestCase and add the following methods:

def create_blob(self, contents, mime_type):
    "Since uploading blobs doesn't work in testing, create them this way."
    fn = files.blobstore.create(mime_type = mime_type,
                                _blobinfo_uploaded_filename = "foo.blt")
    with files.open(fn, 'a') as f:
        f.write(contents)
    files.finalize(fn)
    return files.blobstore.get_blob_key(fn)

def get_blob(self, key):
    return self.blobstore_stub.storage.OpenBlob(key).read()

You will also need the solution here.

For my tests where I would normally do a get or post to a blobstore handler, I instead call one of the two methods above. It is a bit hacky but it works.

Another solution I am considering is to use Selenium's HtmlUnit driver. This would require the dev server to be running but should allow full testing of blobstore and also javascript (as a side benefit).

Upvotes: 3

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