graphex graph all fails when no modules match the query (#59)

ChangeLog.md

@@ -2,6 +2,8 @@
 
 ## Unreleased changes
 
+- `graphex graph all` now fails when no modules match the query.
+
 ## 0.1.2.1
 
 - Fix `graphex cabal` for units with multiple source directories.

app/Main.hs

@@ -1,13 +1,15 @@
 {-# LANGUAGE ApplicativeDo #-}
 module Main where
 
+import           Control.Monad            (when)
 import           Data.Aeson               (encode)
 import           Data.Bool                (bool)
 import qualified Data.ByteString.Lazy     as BL
 import qualified Data.Csv                 as CSV
 import           Data.Foldable
 import           Data.List.NonEmpty       (NonEmpty (..))
 import qualified Data.List.NonEmpty       as NE
+import qualified Data.Map                 as Map
 import           Data.Maybe               (fromMaybe)
 import           Data.Text                (Text)
 import qualified Data.Text                as T
@@ -137,7 +139,8 @@ main = customExecParser (prefs showHelpOnError) opts >>= \case
         AllDepsOn{..}      -> do
           let ms =
                 if | useRegex -> filter (\m -> any (m =~) patterns) (graphNodes graph)
-                   | otherwise -> NE.toList patterns
+                   | otherwise -> filter (flip Map.member (unGraph graph)) $ NE.toList patterns
+          when (null ms) $ error $ unwords ["No nodes in the graph match:", show patterns]
           printStrs $ foldMap (allDepsOn graph) ms
         Rankings         -> printStrs $ fmap (\(n,m) -> m <> " - " <> (T.pack . show) n) $ rankings graph
         FindLongest      -> printStrs $ longest graph