Integrate elm-check

README.md

@@ -7,6 +7,8 @@ Provides an efficient development workflow and a starting point for building Elm
 - automated build of all application resources using [webpack](http://webpack.github.io/)
 - Hot Module Replacement for the Elm code using [elm-hot-loader](https://github.com/fluxxu/elm-hot-loader)
 - automatic re-execution of tests on source change for Elm and JavaScript code
+- property based testing using [elm-check](https://github.com/NoRedInk/elm-check) for the Elm tests
+- test coverage using [istanbul](https://github.com/gotwarlost/istanbul) for the JavaScript tests
 - [Semantic UI](http://semantic-ui.com/) integration
 - JavaScript code written in ES6, transpiled using [Babel](https://babeljs.io/)
 - JavaScript linted using [eslint](http://eslint.org/)

elm-package.json

@@ -9,6 +9,7 @@
     ],
     "exposed-modules": [],
     "dependencies": {
+        "NoRedInk/elm-check": "3.0.0 <= v < 4.0.0",
         "deadfoxygrandpa/elm-test": "3.1.0 <= v < 4.0.0",
         "elm-lang/core": "3.0.0 <= v < 4.0.0",
         "evancz/elm-effects": "2.0.1 <= v < 3.0.0",
@@ -18,4 +19,4 @@
         "laszlopandy/elm-console": "1.1.0 <= v < 2.0.0"
     },
     "elm-version": "0.16.0 <= v < 0.17.0"
-}
+}

elm-test/App/SampleTest.elm

@@ -4,14 +4,28 @@ module App.SampleTest
 
 import App.Sample exposing (sum, product)
 import ElmTest exposing (Test, test, suite, assertEqual)
+import Check exposing (Claim, Evidence, claim, that, is, true, for, quickCheck)
+import Check.Producer exposing (filter, tuple, int, float)
+import Check.Test exposing (evidenceToTest)
 
 testSuite : Test
 testSuite =
   suite "App.Sample"
     [ suite "sum"
-        [ test "should return a sum of 2 numbers" <| assertEqual 8 (sum 3 5)
+        [ test "should return a sum of 2 Ints" <| assertEqual 8 (sum 3 5)
+        , test "should return a sum of 2 Floats" <| assertEqual -10.5 (sum -20.5 10)
         ]
-    , suite "product"
-        [ test "should return a product of 2 numbers" <| assertEqual 15 (product 3 5)
+    , evidenceToTest << quickCheck <| Check.suite "product"
+        [ claim "should multiply Ints"
+            `that` (\(a, b) -> product a b)
+            `is` (\(a, b) -> a * b)
+            `for` tuple (int, int)
+        , claim "should multiply Floats"
+            `that` (\(a, b) -> product a b)
+            `is` (\(a, b) -> a * b)
+            `for` tuple (float, float)
+        , claim "should be inverted by division with minimal imprecision"
+            `true` (\(a, b) -> abs (product a b / b - a) < 1e-10)
+            `for` (filter (\(a, b) -> b /= 0) (tuple (float, float)))
         ]
     ]