A structured test runner, incorporating:

• The expectations to run
• The hierarchy of description strings that describe the results

Convert a Test into a Runner.

In order to run any fuzz tests that the Test may have, it requires a default run count as well as an initial Random.Pcg.Seed. 100 is a good run count. To obtain a good random seed, pass a random 32-bit integer to Random.Pcg.initialSeed. You can obtain such an integer by running Math.floor(Math.random()*0xFFFFFFFF) in Node. It's typically fine to hard-code this value into your Elm code; it's easy and makes your tests reproducible.

An unevaluated test. Run it with run to evaluate it into a list of Expectations.

Evaluate a Runnable to get a list of Expectations.

A standard way to format descriptiona and test labels, to keep things consistent across test runner implementations.

The HTML, Node, String, and Log runners all use this.

What it does:

• drop any labels that are empty strings

• format the first label differently from the others

• reverse the resulting list

  [ "the actual test that failed" , "nested description failure" , "top-level description failure" ] |> formatLabels ((++) "↓ ") ((++) "✗ ")

  {- [ "↓ top-level description failure" , "↓ nested description failure" , "✗ the actual test that failed" ] -}