collecting-tests.md

Collecting tests

1. Use tree-sitter-elm to get all the exposed functions from every test modules.

2. Create a main module a bit like this:

   module Main exposing (main)
   
   import Platform
   import XXX.YYY
   import AAA.BBB
   -- etc
   
   
   findTest : String -> a -> ()
   findTest =
       Debug.todo "replace me"
   
   
   main =
       let
           () =
               findTest "XXX.YYY.zzz1" XXX.YYY.zzz1
   
           () =
               findTest "XXX.YYY.zzz2" XXX.YYY.zzz2
   
           () =
               findTest "AAA.BBB.ccc" AAA.BBB.ccc
   
           () =
               findTest "AAA.BBB.ddd" AAA.BBB.ddd
   
           -- etc
       in
       Platform.woker
           { ... }

3. Compile that main module as an elm application.

4. Replace the generated js for findTest with a function that prints the elm identifier if the second argument is a Test.

5. Run the elm app and inspect the stdout to see all the tests.

Identifying tests

The test custom type is defined elm-explorations:Test.Internal.Test as follows:

type Test
    = UnitTest (() -> List Expectation)
    | FuzzTest (Random.Seed -> Int -> List Expectation)
    | Labeled String Test
    | Skipped Test
    | Only Test
    | Batch (List Test)

or when we have generated javascript:

var $elm_explorations$test$Test$Internal$UnitTest = function (a) {
	return {$: 'UnitTest', a: a};
};
var $elm_explorations$test$Test$Internal$FuzzTest = function (a) {
	return {$: 'FuzzTest', a: a};
};
var $elm_explorations$test$Test$Internal$Labeled = F2(
	function (a, b) {
		return {$: 'Labeled', a: a, b: b};
	});

/* snip */

var $elm_explorations$test$Test$Runner$Skipping = function (a) {
	return {$: 'Skipping', a: a};
};

First we want to insert the following near the top of the file:

var testSymbol = Symbol('testSymbol');

We want to do a find and replace on this js to instead get:

var $elm_explorations$test$Test$Internal$UnitTest = function (a) {
	return {[testSymbol]: true, $: 'UnitTest', a: a};
};
var $elm_explorations$test$Test$Internal$FuzzTest = function (a) {
	return {[testSymbol]: true, $: 'FuzzTest', a: a};
};
var $elm_explorations$test$Test$Internal$Labeled = F2(
	function (a, b) {
		return {[testSymbol]: true, $: 'Labeled', a: a, b: b};
	});

/* snip */

var $elm_explorations$test$Test$Runner$Skipping = function (a) {
	return {[testSymbol]: true, $: 'Skipping', a: a};
};

Then the findTests function can be:

var $author$project$Main$findTests = F2(
	function (elmIndentifier, value) {
		if (value[testSymbol]) {
            console.log(elmIndentifier);
        }
	});