Merge pull request #2044 from github/js-exports

Eval `export function ...` in JavaScript

src/Data/Syntax/Declaration.hs

@@ -10,7 +10,7 @@ import           Prologue
 import           Proto3.Suite.Class
 
 data Function a = Function { functionContext :: ![a], functionName :: !a, functionParameters :: ![a], functionBody :: !a }
-  deriving (Eq, Ord, Show, Foldable, Traversable, Functor, Generic1, Hashable1, Mergeable, FreeVariables1, Declarations1, ToJSONFields1, Named1, Message1)
+  deriving (Eq, Ord, Show, Foldable, Traversable, Functor, Generic1, Hashable1, Mergeable, FreeVariables1, ToJSONFields1, Named1, Message1)
 
 instance Diffable Function where
   equivalentBySubterm = Just . functionName
@@ -33,6 +33,11 @@ instance Evaluatable Function where
 instance Declarations a => Declarations (Function a) where
   declaredName Function{..} = declaredName functionName
 
+instance Declarations1 Function where
+  liftDeclaredName declaredName Function{..} =
+    case declaredName functionName of
+      [] -> Nothing
+      (x:_) -> Just x
 
 data Method a = Method { methodContext :: ![a], methodReceiver :: !a, methodName :: !a, methodParameters :: ![a], methodBody :: !a }
   deriving (Eq, Ord, Show, Foldable, Traversable, Functor, Generic1, Hashable1, Mergeable, FreeVariables1, Declarations1, ToJSONFields1, Named1, Message1)

src/Language/TypeScript/Syntax.hs

@@ -270,10 +270,10 @@ instance Show1 DefaultExport where liftShowsPrec = genericLiftShowsPrec
 
 instance Evaluatable DefaultExport where
   eval (DefaultExport term) = do
-    v <- subtermValue term
     case declaredName term of
       Just name -> do
         addr <- lookupOrAlloc name
+        v <- subtermValue term
         assign addr v
         export name name Nothing
         bind name addr

test/fixtures/javascript/analysis/exports/lib.js

@@ -0,0 +1,6 @@
+export function square(x) {
+    return x * x;
+}
+export function area(x, y) {
+  return x * y;
+}

test/fixtures/javascript/analysis/exports/main.js

@@ -0,0 +1,3 @@
+import { square, area } from 'lib';
+console.log(square(11)); // 121
+console.log(area(4, 3)); // 12