test for fast (not TH).

test/data/Bar.hs

@@ -0,0 +1,5 @@
+{-# LANGUAGE TemplateHaskell #-}
+module Bar (bar) where
+import Foo (foo)
+
+bar = $foo ++ "bar"

test/data/Foo.hs

@@ -0,0 +1,5 @@
+module Foo (foo) where
+import Language.Haskell.TH
+
+foo :: ExpQ
+foo = stringE "foo"

test/data/Main.hs

@@ -0,0 +1,3 @@
+import Bar (bar)
+
+main = putStrLn bar