Data.Music.Lilypond: Add regression test for tempo

test/Regression.hs

@@ -1,5 +1,5 @@
-
 import Data.ByteString.Lazy (ByteString, fromStrict)
+import qualified Data.Music.Lilypond as Lilypond
 import Data.Text (pack)
 import Data.Text.Encoding (encodeUtf8)
 import Music.Prelude (Music, c, d, e, pseq, timeSignature, (|>))
@@ -13,16 +13,39 @@ toLilypondRaw :: Music -> IO ByteString
 toLilypondRaw music = do
   work <- runIOExportM $ toStandardNotation music
   (h, ly) <- runIOExportM $ toLy defaultLilypondOptions work
-  let ly' = h ++ show (Text.Pretty.pretty ly)
+  toLilypondRaw' h ly
+
+toLilypondRaw' :: String -> Lilypond.Music -> IO ByteString
+toLilypondRaw' header ly = do
+  let ly' = header ++ show (Text.Pretty.pretty ly)
   pure $ fromStrict $ encodeUtf8 $ pack ly'
 
+lilypondRegresionTest name =
+  goldenVsString
+    name
+    ("test/regression/lilypond" ++ name ++ ".ly")
+
 tests :: [TestTree]
 tests =
-  [ goldenVsString
-      "tempo-change-generated"
-      "test/regression/lilypond/tempo-change-generated.ly"
-      $ do
-        toLilypondRaw $ c |> timeSignature (3 / 4) (pseq [d, e])
+  [ lilypondRegresionTest
+      "tempo-change-generated" -- TODO this is time, not tempo, fix!!
+      $ toLilypondRaw $ c |> timeSignature (3 / 4) (pseq [d, e]),
+    lilypondRegresionTest
+      "data-lilypond-tempo-change-text-generated"
+      $ toLilypondRaw'
+        ""
+        ( Lilypond.sequential
+            (Lilypond.Tempo (Just "Allegro") Nothing)
+            (Lilypond.Note c Nothing [])
+        ),
+    lilypondRegresionTest
+      "data-lilypond-tempo-change-bpm-generated"
+      $ toLilypondRaw'
+        ""
+        ( Lilypond.sequential
+            (Lilypond.Tempo Nothing (Just (1 / 4, 120)))
+            (Lilypond.Note c Nothing [])
+        )
   ]
 
 main = defaultMain (testGroup "Regression tests" tests)

test/regression/lilypond/data-lilypond-tempo-change-bpm-generated.ly

@@ -0,0 +1 @@
+{ \tempo 4 = 120 c,,,, }

test/regression/lilypond/data-lilypond-tempo-change-text-generated.ly

@@ -0,0 +1 @@
+{ \tempo "Allegro" c,,,, }