Can someone explain how the testLoad method works in flutter_dotenv?

Question

I am using environment variables for testing (username and password).

I have my .env file setup.

I also have the flutter_dotenv imported in my test file as per:

However, under "Using in tests #" it mentions using the method testLoad to load a static set of variables for testing.

The document also offers 2 examples:

Example 1: Loading from a static string.

dotenv.testLoad(fileInput: '''FOO=foo
BAR=bar
''');

Example 2: Loading from a file synchronously.

dotenv.testLoad(fileInput: File('test/.env').readAsStringSync());

Can someone explain how these examples work?

In Example 1, it seems the testLoad method would return all variables listed in .env in a single call.

So I have a USERNAME=Bobby and a PASSWORD=1234 in my .env file. If I use testLoad it would return both Bobby and 1234.

However, I don't want to get both variables at once. When I test my app, I need to select the field "username" to input the username and afterwards, select the field "password" to input the password; I don't want to input both variables in a single field.

Am I missing something? What use is there for both variables to come in at once?

I also do not understand the use for Example 2 at all.

My guess would be that it separates them, based on the fact that there is a line feed in the assignment, so that it's provided as two lines and not one, and that you would end up with two separate variables (USERNAME and PASSWORD), not just one. The second looks pretty self-explanatory; you would put the variable assignments in a text file, one on each line, and pass that filename as the File() argument, and it would read the lines in the file and create the variables. I doubt in either case that the variables both come in at once. Couldn't you just do a quick test to find out? — Ken White