tools: add easytest (github) as an extra dep, for experiments

stack.yaml

@@ -7,11 +7,14 @@ nix:
   pure: false
   packages: [perl gmp ncurses zlib]
 
-extra-deps: []
-
 packages:
 - hledger-lib
 - hledger
 - hledger-ui
 - hledger-web
 - hledger-api
+
+extra-deps:
+# for tools/easytest.hs. Should be harmless otherwise.
+- git: git@github.com:joelburget/easytest.git
+  commit: 5d5b851e77368071b5727cd366af9c6ecd288add

tools/easytest.hs

@@ -0,0 +1,36 @@
+#!/usr/bin/env stack
+-- stack runghc --install-ghc --package easytest
+-- (use project's resolver)
+
+-- stack script --resolver lts-10.3 --package easytest
+-- (use specific resolver, be more self-contained)
+
+-- Examples of https://github.com/joelburget/easytest, an easier testing framework.
+
+{-# LANGUAGE OverloadedStrings #-}
+
+import EasyTest
+import Control.Applicative
+import Control.Monad
+
+suite1 :: Test ()
+suite1 = tests
+  [ scope "a" ok
+  , scope "b.c" ok
+  , scope "b" ok
+  , scope "b" . scope "c" . scope "d" $ ok
+  , scope "c" ok ]
+
+reverseTest :: Test ()
+reverseTest = scope "list reversal" $ do
+  nums <- listsOf [0..100] (int' 0 99)
+  nums `forM_` \nums -> expect (reverse (reverse nums) == nums)
+
+main :: IO ()
+main = do
+  run suite1
+  runOnly "a" suite1
+  runOnly "b" suite1
+  runOnly "b" $ tests [suite1, scope "xyz" (crash "never run")]
+  runOnly "b.c" $ tests [suite1, scope "b" (crash "never run")]
+  run reverseTest