Non-string header values on http response throws error

[ahmelsayed]

From @graham-sportsmgmt on February 17, 2018 3:49

azure-functions-core-tools@2.0.1-beta.22
JavaScript HttpTrigger
Local function emulator on Windows 10 x64

I am trying to set a response header in order to flag the length of the result set to our front end code.

This method throws an error:

context.res = {
  "headers" : { "length": response.length },
  "body": response
};

invocationResponse.outputData.data.http.headers: string{k:string} expected

This method doesn't throw an error, but adds no header to the response:

context.res.setHeader('length', response.length);

Copied from original issue: Azure/azure-functions-core-tools#386

[ahmelsayed]

From @pilot4u on February 22, 2018 11:55

I'm struggling with this issue as well, has anyone managed to overcome this issue?

[pragnagopa]

@mhoeger - here is the test that might be throwing the same error BadContentType_ThrowsExpectedException_Conneg

Right now headers in the proto file are key ,value pairs: RpcHttp Header. Please investigate if we need to move to
map<string,TypedData> headers = 3;

[mhoeger]

Thanks for finding the related test! I think you're right that we should be able to accept TypedData instead of just string, since V1 lets users do this.

The error is that we only accept string:string key value pairs on http headers right now.
The workaround is to cast the header value to a string.

[pragnagopa]

This issue was moved to Azure/azure-functions-language-worker-protobuf#9