From d604ac7763f5b5e7e40f015dffb2482d88f6cb3e Mon Sep 17 00:00:00 2001
From: Daniel Wagner <daniel@wagner-home.com>
Date: Fri, 7 Dec 2012 18:31:59 -0800
Subject: [PATCH] add a way to run regression tests

Ignore-this: 5a811f403a442afc19ef9ae2874ac4ae

darcs-hash:20121208023159-76d51-feb50029c8fa6fd30e43e627d1f996ab898f7649
---
 tests/GenerateRegressionTests.hs | 40 --------------------
 tests/RegressionTest.hs          | 65 ++++++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+), 40 deletions(-)
 delete mode 100644 tests/GenerateRegressionTests.hs
 create mode 100644 tests/RegressionTest.hs

diff --git a/tests/GenerateRegressionTests.hs b/tests/GenerateRegressionTests.hs
deleted file mode 100644
index 80c35ba..0000000
--- a/tests/GenerateRegressionTests.hs
+++ /dev/null
@@ -1,40 +0,0 @@
-{-# LANGUAGE NoMonomorphismRestriction #-}
-import Control.Monad
-import Data.ByteString (pack)
-import Data.Encoding
-import System.Random
-
--- for example:
-import Data.Encoding.ISO2022JP
-main = generate ISO2022JP
--- end example
-
-randomRepeat f max = randomRIO (0, max) >>= flip replicateM f
-randomString = randomRepeat randomIO
-randomGoodString = randomRepeat . randomGoodChar
-randomGoodChar f = let
-	good = filter f [minBound..maxBound]
-	n    = length good
-	in do
-	i <- randomRIO (0, n-1)
-	return (good !! i)
-
-generate enc = do
-	let filename = show enc ++ ".regression"
-	    randomGood = randomGoodString (encodeable enc)
-	shortMixedEnc <- replicateM  300 (randomString   10)
-	shortGoodEnc  <- replicateM   30 (randomGood     10)
-	longMixedEnc  <- replicateM  300 (randomString 1000)
-	longGoodEnc   <- replicateM 3000 (randomGood   1000)
-	shortDec      <- replicateM  300 (randomString   10)
-	longDec       <- replicateM 3000 (randomString 1000)
-	writeFile filename (show
-		[ (s, encodeStrictByteStringExplicit enc s)
-		| ss <- [shortMixedEnc, shortGoodEnc, longMixedEnc, longGoodEnc]
-		, s <- ss
-		] ++ "\n")
-	appendFile filename (show
-		[ (bs, decodeStrictByteStringExplicit enc (pack bs))
-		| bss <- [shortDec, longDec]
-		, bs <- bss
-		] ++ "\n")
diff --git a/tests/RegressionTest.hs b/tests/RegressionTest.hs
new file mode 100644
index 0000000..b1f4728
--- /dev/null
+++ b/tests/RegressionTest.hs
@@ -0,0 +1,65 @@
+{-# LANGUAGE NoMonomorphismRestriction #-}
+import Control.Applicative
+import Control.Monad
+import Data.ByteString (ByteString, pack)
+import Data.Encoding
+import Data.Word
+import System.Random
+
+-- for example:
+import Data.Encoding.ISO2022JP
+--main = generate ISO2022JP
+main = test ISO2022JP
+-- end example
+
+randomRepeat f max = randomRIO (0, max) >>= flip replicateM f
+randomString = randomRepeat randomIO
+randomGoodString = randomRepeat . randomGoodChar
+randomGoodChar f = let
+	good = filter f [minBound..maxBound]
+	n    = length good
+	in do
+	i <- randomRIO (0, n-1)
+	return (good !! i)
+
+generate enc = do
+	let filename = show enc ++ ".regression"
+	    randomGood = randomGoodString (encodeable enc)
+	shortMixedEnc <- replicateM  300 (         randomString   10)
+	shortGoodEnc  <- replicateM   30 (         randomGood     10)
+	longMixedEnc  <- replicateM  300 (         randomString 1000)
+	longGoodEnc   <- replicateM 3000 (         randomGood   1000)
+	shortDec      <- replicateM  300 (pack <$> randomString   10)
+	longDec       <- replicateM 3000 (pack <$> randomString 1000)
+	writeFile filename (show
+		[ (s, encodeStrictByteStringExplicit enc s)
+		| ss <- [shortMixedEnc, shortGoodEnc, longMixedEnc, longGoodEnc]
+		, s <- ss
+		] ++ "\n")
+	appendFile filename (show
+		[ (bs, decodeStrictByteStringExplicit enc bs)
+		| bss <- [shortDec, longDec]
+		, bs <- bss
+		] ++ "\n")
+
+complain action input expected actual = when (expected /= actual) . putStrLn . concat $
+	[ "when "
+	, pad action
+	, show input
+	, "\n"
+	, pad "expected"
+	, show expected
+	, "\n"
+	, pad "but got"
+	, show actual
+	]
+	where
+	size  = maximum . map length $ [action, "expected", "but got"]
+	pad s = s ++ replicate (size - length s) ' ' ++ ": "
+
+test enc = do
+	[encoded_, decoded_] <- lines <$> readFile (show enc ++ ".regression")
+	let encoded = read encoded_
+	    decoded = read decoded_
+	forM_ encoded $ \(s , correctEncoding) -> complain "encoding"  s correctEncoding (encodeStrictByteStringExplicit enc  s)
+	forM_ decoded $ \(bs, correctDecoding) -> complain "decoding" bs correctDecoding (decodeStrictByteStringExplicit enc bs)