2.3 Test Selectors

Functions like ert accept a test selector, a Lisp expression specifying a set of tests. Test selector syntax is similar to Common Lisp’s type specifier syntax:

• nil selects no tests.
• t selects all tests.
• :new selects all tests that have not been run yet.
• :failed and :passed select tests according to their most recent result.
• :expected, :unexpected select tests according to their most recent result.
• A string is a regular expression that selects all tests with matching names.
• A test (i.e., an object of ert-test data type) selects that test.
• A symbol selects the test that the symbol names.
• (member TESTS...) selects the elements of TESTS, a list of tests or symbols naming tests.
• (eql TEST) selects TEST, a test or a symbol naming a test.
• (and SELECTORS...) selects the tests that match all SELECTORS.
• (or SELECTORS...) selects the tests that match any SELECTOR.
• (not SELECTOR) selects all tests that do not match SELECTOR.
• (tag TAG) selects all tests that have TAG on their tags list. (Tags are optional labels you can apply to tests when you define them.)
• (satisfies PREDICATE) selects all tests that satisfy PREDICATE, a function that takes a test as argument and returns non-nil if it is selected.

Selectors that are frequently useful when selecting tests to run include t to run all tests that are currently defined in Emacs, "^foo-" to run all tests in package foo (this assumes that package foo uses the prefix foo- for its test names), result-based selectors such as (or :new :unexpected) to run all tests that have either not run yet or that had an unexpected result in the last run, and tag-based selectors such as (not (tag :causes-redisplay)) to run all tests that are not tagged :causes-redisplay.