Positive Testing
Positive testing verifies that a system behaves correctly when given valid, expected input — confirming the happy path works as designed. It's usually the first and most obvious category of test written for any feature, checked before anyone considers what happens with bad input.
Positive test cases are typically the easiest to write and the first ones a team creates: enter a valid email and password, submit the form, confirm login succeeds. They confirm the core functionality exists and works, but on their own give a false sense of completeness.
A test suite made up entirely of positive tests can reach high pass rates while still shipping a fragile product, because it never checks what happens when input isn't perfect. Positive and negative testing are meant to be paired, not chosen between.
