TestClient: EnvironBuilder cannot be passed in

[mitsuhiko]

In a normal test client from werkzeug you can pass the environment builder in. With Flask that is currently not possible. In some situations people might want to interface with the builder directly.

[davidism]

I'm assuming you mean passing an EnvironBuilder to FlaskClient.open?

[pachewise]

would FlaskClient.open simply use the EnvironBuilder passed in (without the defaults in make_test_environ_builder)?

[mitsuhiko]

@davidism yeah. or at least have an option to play with the builder before its being used to create the environment.

[davidism]

What happens if they've overridden client.environ_base? Does that get ignored? Or ignored for for EnvironBuilder but not dict instances?

How should environ.environ_overrides['flask._preserve_context'] be handled? It's required for keeping the behavior of the test client, but setting it would mutate the passed environ.

[mitsuhiko]

A crude way could be to pass in a function that is called with the builder so you can modify it before open takes place.