Try loading a module if findModule failed for it

Language/Haskell/GhcMod/Browse.hs

@@ -7,6 +7,7 @@ import Data.List
 import Data.Maybe (fromMaybe)
 import DataCon (dataConRepType)
 import GHC
+import Panic(throwGhcException)
 import Language.Haskell.GhcMod.Doc (showUnqualifiedPage)
 import Language.Haskell.GhcMod.GHCApi
 import Language.Haskell.GhcMod.Types
@@ -50,11 +51,26 @@ browse opt cradle mdlName = do
     void $ initializeFlagsWithCradle opt cradle [] False
     getModule >>= getModuleInfo >>= listExports
   where
-    getModule = findModule (mkModuleName mdlName) Nothing
+    getModule =
+      findModule (mkModuleName mdlName) Nothing
+      `gcatch` (\e ->
+                  case e of
+                    -- findModule works only for package modules, moreover,
+                    -- you cannot load a package module. On the other hand,
+                    -- to browse a local module you need to load it first.
+                    -- If CmdLineError is signalled, we assume the user
+                    -- tried browsing a local module.
+                    CmdLineError _ -> loadAndFind
+                    _ -> throwGhcException e)
     listExports Nothing       = return []
     listExports (Just mdinfo)
       | detailed opt = processModule mdinfo
       | otherwise    = return (processExports mdinfo)
+    loadAndFind = do
+      setTargetFiles [mdlName]
+      checkSlowAndSet
+      void $ load LoadAllTargets
+      findModule (mkModuleName mdlName) Nothing
 
 processExports :: ModuleInfo -> [String]
 processExports = map getOccString . modInfoExports

test/BrowseSpec.hs

@@ -2,8 +2,11 @@ module BrowseSpec where
 
 import Control.Applicative
 import Language.Haskell.GhcMod
+import Language.Haskell.GhcMod.Cradle
 import Test.Hspec
 
+import Dir
+
 spec :: Spec
 spec = do
     describe "browseModule" $ do
@@ -22,3 +25,10 @@ spec = do
             cradle <- findCradle
             syms <- lines <$> browseModule defaultOptions { detailed = True} cradle "Data.Either"
             syms `shouldContain` ["Left :: a -> Either a b"]
+
+    describe "browseModule local" $ do
+        it "lists symbols in a local module" $ do
+            withDirectory_ "test/data" $ do
+                cradle <- findCradleWithoutSandbox
+                syms <- lines <$> browseModule defaultOptions cradle "Baz"
+                syms `shouldContain` ["baz"]