Patch call with new content-type does nothing

[ex-nerd]

As far as I can see in the fake-gcs-server code, contentType is only set when the object is created, and can't be updated.

I'm using the official python gcs library, basically as follows:

# init
from google.cloud import storage
client = BigMessyConnectionToFakeGcsServer(storage.Client)
bucket = client.bucket("my-test-bucket")
key = "test-key"

# upload some data
blob = bucket.blob(key)
blob.upload_from_string(b"some data", content_type="application/octet-stream")

# now fix the content type
blob = bucket.get_blob(key)
blob.content_type = "text/plain"
blob.patch()

The content-type value returned from the API request (buried in google's patch() method definition) is the original unchanged application/octet-stream, as is the content-type when trying to download the blob.

Debugging into google's code, this is sending {"contentType": "application/some-new-type"} along with the API request as the body content, which seems to be completely ignored by Server.patchObject unmarshaling into its metadata struct.

[corytheboyd-smartsheet]

FWIW I think I just ran into this same issue. Wrote the integration test for our feature that updates an object's content-type, and was confused about what I was doing wrong with what I though was a very simple implementation 😅