std.test

Expect, ExpectThrows, Fail, and Skip, what fb test's tests check with.

A @Test Function, one that takes nothing and gives nothing back, though it can throw, is a test, anywhere in a package, and so is one in its tests/ folder, which uses the package from outside. Builds leave tests out, and fb test runs them, in parallel, on as many threads of their own as the pool has workers, so a test that waits for its work leaves the pool to it, but for those whose code uses what only the main thread can. Work a test starts on another thread is the test's, wherever it runs.

Its names are the compiler's own, which a file has with Import std.test, not From or As:

• Expect(condition) and Expect(condition, message): when the condition is False, the test fails, saying what it checked and where, and for a comparison, like Expect(a == b), each side's debug form, then goes on.
• ExpectThrows(x) and ExpectThrows<E>(x): what x throws, which it catches, as Try? would, as an Error? or an E?; when x throws nothing, or nothing that's an E, the test fails, and it gives Null.
• Fail() and Fail(message): the test fails, and goes on.
• Skip() and Skip(reason): the test is skipped, and ends there, as a Return would.

A panic, as a failed Assert's, fails its test, and fb test runs the ones it didn't finish again, and in a debug build, the ones that finished in that run too, whose leaks it didn't check.

Examples

Function Checked(n: Int): Int Throws ArgumentError
    If n < 0 Then Throw ArgumentError(ArgumentErrorKind.INVALID, "negative")
    Return n
End Function

Expect(1 + 1 == 2)
Expect([1, 2].Count == 2, "two elements")
Local error = ExpectThrows<ArgumentError>(Checked(-1))
Expect(error?.Message == "negative")