Merge pull request #59 from rimmington/dollar-quoting

Dollar quoting

Nix/Pretty.hs

@@ -70,7 +70,7 @@ prettyString (Indented parts)
     f ([Plain t] : xs) | Text.null (strip t) = xs
     f xs = xs
   prettyLine = hcat . map prettyPart
-  prettyPart (Plain t) = text . unpack . replace "$" "''$" . replace "''" "'''" $ t
+  prettyPart (Plain t) = text . unpack . replace "${" "''${" . replace "''" "'''" $ t
   prettyPart (Antiquoted r) = text "$" <> braces (withoutParens r)
 
 prettyParams :: Params NixDoc -> Doc

hnix.cabal

@@ -107,6 +107,8 @@ Test-suite hnix-tests
   Other-modules:
     ParserTests
     EvalTests
+    ShorthandTests
+    PrettyTests
   Build-depends:
       base >= 4.3 && < 5
     , containers

tests/Main.hs

@@ -5,6 +5,7 @@ import Test.Tasty
 import qualified ParserTests
 import qualified EvalTests
 import qualified ShorthandTests
+import qualified PrettyTests
 
 import Prelude (IO, ($))
 
@@ -13,4 +14,5 @@ main = defaultMain $ testGroup "hnix"
   [ ParserTests.tests
   , EvalTests.tests
   , ShorthandTests.tests
+  , PrettyTests.tests
   ]

tests/PrettyTests.hs

@@ -0,0 +1,28 @@
+{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE OverloadedStrings #-}
+module PrettyTests (tests) where
+
+import Test.Tasty
+import Test.Tasty.HUnit
+import Test.Tasty.TH
+
+import Nix.Expr
+import Nix.Pretty
+
+case_indented_antiquotation :: Assertion
+case_indented_antiquotation = do
+    assertPretty (mkIndentedStr "echo $foo") "''echo $foo''"
+    assertPretty (mkIndentedStr "echo ${foo}") "''echo ''${foo}''"
+
+case_string_antiquotation :: Assertion
+case_string_antiquotation = do
+    -- TODO: plain $ doesn't need to be escaped here either
+    assertPretty (mkStr "echo $foo") "\"echo \\$foo\""
+    assertPretty (mkStr "echo ${foo}") "\"echo \\${foo}\""
+
+tests :: TestTree
+tests = $testGroupGenerator
+
+--------------------------------------------------------------------------------
+assertPretty :: NExpr -> String -> Assertion
+assertPretty e s = assertEqual ("When pretty-printing " ++ show e) s . show $ prettyNix e