All Magento core features (order placement, product creation, checkout, etc) are covered by automated functional tests. Magento Functional Testing Framework (MFTF) was introduced in order to allow engineers to write tests for the new functionality in very simple sophisticated way. These functional tests are located under each module directory in an MFTF directory: app/code/Magento/<module_name>/Tests/Mftf.
Currently, Magento core has a significant amount of automated test coverage based on the outdated Magento Testing Framework (MTF). We are opening this project to the Community to help convert all valuable tests to the efficient MFTF and to eliminate the maintenance effort of outdated testing framework (MTF).