Happy Path Testing:
This is also known as Golden Path Testing, this focuses on selective execution of tests that do not exercise the software for negative or error conditions.
A headless browser is a web browser without a graphical user interface. Headless browsers provide automated control of a web page in an environment similar to popular web browsers, but are executed via a command-line interface or using network communication. It is suitable for general command-line based testing, within a pre-commit hook, and as part of a continuous integration system.
Headless browsers aren’t faster than real browsers and make it harder to write/debug tests. Anyways customers don’t use headless browsers. Real browsers can also run headlessly.
Heuristic Testing (originally “Heuristic Evaluation” is proposed by Nielsen and Molich, 1990) is a discount method for quick, cheap, and easy evaluation of the user interface.
The process requires that a small set of testers (or “evaluators”) examine the interface, and judge its compliance with recognised usability principles (the “heuristics”). The goal is the identification of any usability issues so that they can be addressed as part of an iterative design process.
Heuristic Testing is popular in Web development.
This is an integration testing involving both Top-Down and Bottom-Up techniques together. Hence is also called Sandwich Testing. This gives a comprehensive coverage in the integration testing.