As a study participant, I want to link my FitBit account so that I can share my sleep data with researchers.

[agretta]

Scenario: The study participant inputs valid FitBit credentials and links their account. Given: The participant has valid FitBit credentials and is on the link device page; When: The participant inputs valid credentials; Then: The FitBit account is authenticated, data is loaded and a success message is then displayed on the screen.

Scenario: The study participant inputs invalid FitBit credentials. Given: The participant's FitBit credentials are not correct when they input them into the link device page; When: The participant inputs credentials Then: The FitBit account is not linked and an error message is displayed on the screen asking them to try again or go to the FitBit website to reset their password.

Scenario: The study participant inputs valid FitBit credentials, but there's a problem with linking the account. Given: The participant's FitBit credentials are correct, but API returns an error for retrieving data; When: the participant is on the link device page and inputs their credentials; Then: The data is not loaded and an appropriate error message is displayed on the screen referencing the API error.

Scenario: The study participant wants to add a second FitBit account. Given: The participant already has a FitBit account linked; When: The participant is on the link device page and attempts to link another; Then: A message is displayed on the screen telling the user only one FitBit account is allowed per user account.

[graham-ely]

Most of the user cases above are invalid in this case as the fitbit account login is handled on fitbit's side, we just send the user over and get data back.

[graham-ely]

@graham-ely fix state detection when navigating to page from dashboard