Don't swallow namespace-parsing errors

Previously, if there was a problem with the inputs and bild failed to
determine the namespace, 'fromPath' would return 'Nothing' and then
'catMaybes' would drop the error-causing input altogether. In the one
time that I had a bad input, this made debugging incredibly difficult.
It's always a bad idea to swallow errors silently, so instead lets just
kill the program if we have bad inputs.

1 files changed, 48 insertions, 7 deletions

diff --git a/Biz/Bild.hs b/Biz/Bild.hs
index d8cdc6f..d178a83 100644
--- a/Biz/Bild.hs
+++ b/Biz/Bild.hs
@@ -10,6 +10,7 @@
 -- | A specific-purpose build tool.
 --
 -- : out bild
+-- : run git
 --
 -- == Design constraints
 --
@@ -157,7 +158,8 @@ main = Cli.Plan help move test_ pure |> Cli.main
       Test.group
         "Biz.Bild"
         [ test_bildBild,
-          test_bildExamples
+          test_bildExamples,
+          test_isGitIgnored
         ]
 
 test_bildBild :: Test.Tree
@@ -196,11 +198,10 @@ move args =
   IO.hSetBuffering stdout IO.NoBuffering
     >> Env.getEnv "CODEROOT" +> \root ->
       Cli.getAllArgs args (Cli.argument "target")
-        |> filter (not <. Namespace.isCab)
         |> filterM Dir.doesFileExist
+        +> filterM (\x -> isGitIgnored x /> don't)
         +> traverse Dir.makeAbsolute
-        /> map (Namespace.fromPath root)
-        /> catMaybes
+        +> traverse (namespaceFromPathOrDie root)
         +> foldM analyze mempty
         /> Map.filter (namespace .> isBuildableNs)
         +> printOrBuild
@@ -223,6 +224,11 @@ move args =
           Just n -> n
     printOrBuild :: Analysis -> IO [ExitCode]
     printOrBuild targets
+      | Map.null targets =
+          Log.wipe
+            >> Log.fail ["bild", "nothing to build"]
+            >> Log.br
+            >> exitWith (ExitFailure 1)
       | args `Cli.has` Cli.longOption "json" =
           Log.wipe >> putJSON targets >> pure [Exit.ExitSuccess]
       | otherwise = do
@@ -233,6 +239,35 @@ move args =
     isLoud = args `Cli.has` Cli.longOption "loud"
     putJSON = Aeson.encode .> ByteString.Lazy.toStrict .> Char8.putStrLn
 
+-- | Don't try to build stuff that isn't part of the git repo.
+isGitIgnored :: FilePath -> IO Bool
+isGitIgnored path =
+  Process.readProcessWithExitCode "git" ["check-ignore", path] ""
+    +> \case
+      (ExitSuccess, _, _) -> pure True
+      (ExitFailure _, _, _) -> pure False
+
+test_isGitIgnored :: Test.Tree
+test_isGitIgnored =
+  Test.group
+    "isGitIgnored"
+    [ Test.unit "filters one" <| do
+        res <- isGitIgnored "_"
+        res @=? True,
+      Test.unit "filters many" <| do
+        traverse isGitIgnored ["Biz/Bild.hs", "__pycache__"]
+          +> (@=? [False, True])
+    ]
+
+namespaceFromPathOrDie :: FilePath -> FilePath -> IO Namespace
+namespaceFromPathOrDie root path =
+  Namespace.fromPath root path |> \case
+    Just x -> pure x
+    Nothing ->
+      Log.fail ["bild", str path, "could not get namespace"]
+        >> Log.br
+        >> exitWith (ExitFailure 1)
+
 nixStore :: String
 nixStore = "/nix/store/00000000000000000000000000000000-"
 
@@ -367,21 +402,24 @@ instance ToNixFlag Builder where
 -- | We can't build everything yet...
 isBuildableNs :: Namespace -> Bool
 isBuildableNs = \case
+  (Namespace _ Namespace.Bash) -> False
   (Namespace _ Namespace.C) -> True
   (Namespace _ Namespace.Css) -> False
   (Namespace _ Namespace.Hs) -> True
+  (Namespace _ Namespace.Html) -> False
   (Namespace _ Namespace.Json) -> False
   (Namespace _ Namespace.Keys) -> False
   (Namespace _ Namespace.Lisp) -> True
   (Namespace _ Namespace.Md) -> False
+  (Namespace path Namespace.Nix)
+    | path `elem` nixTargets -> True
+    | otherwise -> False
   (Namespace _ Namespace.None) -> False
   (Namespace _ Namespace.Py) -> True
   (Namespace _ Namespace.Sh) -> False
   (Namespace _ Namespace.Scm) -> True
   (Namespace _ Namespace.Rs) -> True
-  (Namespace path Namespace.Nix)
-    | path `elem` nixTargets -> True
-    | otherwise -> False
+  (Namespace _ Namespace.Toml) -> True
   where
     nixTargets =
       [ ["Biz", "Pie"],
@@ -461,11 +499,14 @@ analyze hmap ns = case Map.lookup ns hmap of
               /> Text.lines
       case ext of
         -- basically we don't support building these
+        Namespace.Bash -> pure Nothing
         Namespace.Css -> pure Nothing
         Namespace.Json -> pure Nothing
         Namespace.Keys -> pure Nothing
         Namespace.Md -> pure Nothing
         Namespace.None -> pure Nothing
+        Namespace.Html -> pure Nothing
+        Namespace.Toml -> pure Nothing
         Namespace.Py ->
           contentLines
             |> Meta.detectAll "#"