Implement builtins.currentTime

hnix.cabal

@@ -2,7 +2,7 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 495fbcc0ec91c76bd2a6f9a571bca3014f7dd68489dc137eb17528a4dfde7a00
+-- hash: 3939e6333d509e27377d1de951e2b57efc80952e134d6666a530407b9aa32b3d
 
 name:           hnix
 version:        0.5.0
@@ -118,6 +118,7 @@ library
     , template-haskell
     , text
     , these
+    , time
     , transformers
     , unix
     , unordered-containers >=0.2.9 && <0.3
@@ -158,6 +159,7 @@ executable hnix
     , serialise
     , template-haskell
     , text
+    , time
     , transformers
     , unordered-containers >=0.2.9 && <0.3
   if flag(tracing)
@@ -201,6 +203,7 @@ test-suite hnix-tests
     , tasty-th
     , template-haskell
     , text
+    , time
     , transformers
     , unix
     , unordered-containers >=0.2.9 && <0.3
@@ -234,6 +237,7 @@ benchmark hnix-benchmarks
     , serialise
     , template-haskell
     , text
+    , time
     , transformers
     , unordered-containers >=0.2.9 && <0.3
   if flag(tracing)

main/Main.hs

@@ -19,6 +19,7 @@ import qualified Data.HashMap.Lazy as M
 import qualified Data.Map as Map
 import           Data.List (sortOn)
 import           Data.Maybe (fromJust)
+import           Data.Time
 import qualified Data.Text as Text
 import qualified Data.Text.IO as Text
 import qualified Data.Text.Lazy.Encoding as TL
@@ -39,7 +40,8 @@ import qualified Text.Show.Pretty as PS
 
 main :: IO ()
 main = do
-    opts <- execParser nixOptionsInfo
+    time <- liftIO getCurrentTime
+    opts <- execParser (nixOptionsInfo time)
     runLazyM opts $ case readFrom opts of
         Just path -> do
             let file = addExtension (dropExtension path) "nix"

package.yaml

@@ -28,6 +28,7 @@ dependencies:
   - serialise
   - template-haskell
   - text
+  - time
   - transformers
   - unordered-containers        >= 0.2.9 && < 0.3
 

src/Nix/Builtins.hs

@@ -23,6 +23,7 @@ module Nix.Builtins (builtins) where
 import           Control.Monad
 import           Control.Monad.Catch
 import           Control.Monad.ListM (sortByM)
+import           Control.Monad.Reader (asks)
 import qualified Crypto.Hash.MD5 as MD5
 import qualified Crypto.Hash.SHA1 as SHA1
 import qualified Crypto.Hash.SHA256 as SHA256
@@ -51,6 +52,7 @@ import           Data.Text.Encoding
 import qualified Data.Text.Lazy as LazyText
 import qualified Data.Text.Lazy.Builder as Builder
 import           Data.These (fromThese)
+import qualified Data.Time.Clock.POSIX as Time
 import           Data.Traversable (mapM)
 import           Language.Haskell.TH.Syntax (addDependentFile, runIO)
 import           Nix.Atoms
@@ -62,6 +64,7 @@ import           Nix.Expr.Types
 import           Nix.Expr.Types.Annotated
 import           Nix.Frames
 import           Nix.Normal
+import           Nix.Options
 import           Nix.Parser
 import           Nix.Render
 import           Nix.Scope
@@ -122,6 +125,7 @@ builtinsList = sequence [
     , add  Normal   "concatLists"                concatLists
     , add' Normal   "concatStringsSep"           (arity2 Text.intercalate)
     , add0 Normal   "currentSystem"              currentSystem
+    , add0 Normal   "currentTime"                currentTime_
     , add2 Normal   "deepSeq"                    deepSeq
     , add0 TopLevel "derivation"                 $(do
           let f = "data/nix/corepkgs/derivation.nix"
@@ -929,6 +933,11 @@ currentSystem = do
   arch <- getCurrentSystemArch
   return $ nvStr (arch <> "-" <> os) mempty
 
+currentTime_ :: MonadNix e m => m (NValue m)
+currentTime_ = do
+    opts :: Options <- asks (view hasLens)
+    toNix @Integer $ round $ Time.utcTimeToPOSIXSeconds (currentTime opts)
+
 derivationStrict_ :: MonadNix e m => m (NValue m) -> m (NValue m)
 derivationStrict_ = (>>= derivationStrict)
 

src/Nix/Options.hs

@@ -5,6 +5,7 @@ import           Data.Char (isDigit)
 import           Data.Maybe (fromMaybe)
 import           Data.Text (Text)
 import qualified Data.Text as Text
+import           Data.Time
 import           Options.Applicative hiding (ParserResult(..))
 import           Text.PrettyPrint.ANSI.Leijen hiding ((<$>))
 
@@ -36,12 +37,13 @@ data Options = Options
     , arg          :: [(Text, Text)]
     , argstr       :: [(Text, Text)]
     , fromFile     :: Maybe FilePath
+    , currentTime  :: UTCTime
     , filePaths    :: [FilePath]
     }
     deriving Show
 
-defaultOptions :: Options
-defaultOptions = Options
+defaultOptions :: UTCTime -> Options
+defaultOptions current = Options
     { verbose      = ErrorsOnly
     , tracing      = False
     , thunks       = False
@@ -69,6 +71,7 @@ defaultOptions = Options
     , arg          = []
     , argstr       = []
     , fromFile     = Nothing
+    , currentTime  = current
     , filePaths    = []
     }
 
@@ -96,8 +99,8 @@ argPair = option $ str >>= \s ->
             "Format of --arg/--argstr in hnix is: name=expr"
         Just i -> return $ second Text.tail $ Text.splitAt i s
 
-nixOptions :: Parser Options
-nixOptions = Options
+nixOptions :: UTCTime -> Parser Options
+nixOptions current = Options
     <$> (fromMaybe ErrorsOnly <$>
          optional
            (option (do a <- str
@@ -189,8 +192,13 @@ nixOptions = Options
         (   short 'f'
          <> long "file"
          <> help "Parse all of the files given in FILE; - means stdin"))
+    <*> option (parseTimeOrError True defaultTimeLocale "%Y/%m/%d %H:%M:%S" <$> str)
+        (   long "now"
+         <> value current
+         <> help "Set current time for testing purposes")
     <*> many (strArgument (metavar "FILE" <> help "Path of file to parse"))
 
-nixOptionsInfo :: ParserInfo Options
-nixOptionsInfo = info (helper <*> nixOptions)
-                      (fullDesc <> progDesc "" <> header "hnix")
+nixOptionsInfo :: UTCTime -> ParserInfo Options
+nixOptionsInfo current =
+    info (helper <*> nixOptions current)
+         (fullDesc <> progDesc "" <> header "hnix")

tests/EvalTests.hs

@@ -14,6 +14,7 @@ import qualified Data.HashMap.Lazy as M
 import           Data.Maybe (isJust)
 import           Data.String.Interpolate.IsString
 import           Data.Text (Text)
+import           Data.Time
 import           Nix
 import qualified System.Directory as D
 import           System.Environment
@@ -174,10 +175,12 @@ instance (Show r, Show (NValueF m r), Eq r) => Eq (NValueF m r) where
 
 constantEqual :: NExprLoc -> NExprLoc -> Assertion
 constantEqual a b = do
+    time <- liftIO getCurrentTime
+    let opts = defaultOptions time
     -- putStrLn =<< lint (stripAnnotation a)
-    a' <- runLazyM defaultOptions $ normalForm =<< nixEvalExprLoc Nothing a
+    a' <- runLazyM opts $ normalForm =<< nixEvalExprLoc Nothing a
     -- putStrLn =<< lint (stripAnnotation b)
-    b' <- runLazyM defaultOptions $ normalForm =<< nixEvalExprLoc Nothing b
+    b' <- runLazyM opts $ normalForm =<< nixEvalExprLoc Nothing b
     assertEqual "" a' b'
 
 constantEqualText' :: Text -> Text -> Assertion

tests/Main.hs

@@ -8,11 +8,13 @@ module Main where
 import           Control.DeepSeq
 import qualified Control.Exception as Exc
 import           Control.Monad
+import           Control.Monad.IO.Class
 import           Data.Fix
 import           Data.List (isInfixOf)
 import           Data.Maybe (isJust)
 import           Data.String.Interpolate.IsString
 import           Data.Text (unpack)
+import           Data.Time
 import qualified EvalTests
 import qualified Nix
 import           Nix.Exec
@@ -57,7 +59,9 @@ ensureNixpkgsCanParse =
           url    = "https://github.com/NixOS/nixpkgs/archive/#{rev}.tar.gz";
           sha256 = "#{sha256}";
         }|]) $ \expr -> do
-        NVStr dir _ <- runLazyM defaultOptions $ Nix.nixEvalExprLoc Nothing expr
+        NVStr dir _ <- do
+            time <- liftIO getCurrentTime
+            runLazyM (defaultOptions time) $ Nix.nixEvalExprLoc Nothing expr
         files <- globDir1 (compile "**/*.nix") (unpack dir)
         forM_ files $ \file ->
           -- Parse and deepseq the resulting expression tree, to ensure the

tests/NixLanguageTests.hs

@@ -15,6 +15,7 @@ import           Data.Map (Map)
 import qualified Data.Map as Map
 import qualified Data.Text as Text
 import qualified Data.Text.IO as Text
+import           Data.Time
 import           GHC.Exts
 import           Nix.Lint
 import           Nix.Options
@@ -68,12 +69,15 @@ genTests = do
     mkTestGroup (kind, tests) =
         testGroup (unwords kind) $ map (mkTestCase kind) tests
     mkTestCase kind (basename, files) =
-        testCase (takeFileName basename) $ case kind of
-            ["parse", "okay"] -> assertParse defaultOptions $ the files
-            ["parse", "fail"] -> assertParseFail defaultOptions $ the files
-            ["eval", "okay"]  -> assertEval defaultOptions files
-            ["eval", "fail"]  -> assertEvalFail $ the files
-            _ -> error $ "Unexpected: " ++ show kind
+        testCase (takeFileName basename) $ do
+            time <- liftIO getCurrentTime
+            let opts = defaultOptions time
+            case kind of
+                ["parse", "okay"] -> assertParse opts $ the files
+                ["parse", "fail"] -> assertParseFail opts $ the files
+                ["eval", "okay"]  -> assertEval opts files
+                ["eval", "fail"]  -> assertEvalFail $ the files
+                _ -> error $ "Unexpected: " ++ show kind
 
 assertParse :: Options -> FilePath -> Assertion
 assertParse _opts file = parseNixFileLoc file >>= \case
@@ -105,11 +109,13 @@ assertLangOkXml opts file = do
   assertEqual "" expected $ Text.pack actual
 
 assertEval :: Options -> [FilePath] -> Assertion
-assertEval _opts files =
+assertEval _opts files = do
+    time <- liftIO getCurrentTime
+    let opts = defaultOptions time
     case delete ".nix" $ sort $ map takeExtensions files of
-        [] -> () <$ hnixEvalFile defaultOptions (name ++ ".nix")
-        [".exp"] -> assertLangOk defaultOptions name
-        [".exp.xml"] -> assertLangOkXml defaultOptions name
+        [] -> () <$ hnixEvalFile opts (name ++ ".nix")
+        [".exp"] -> assertLangOk opts name
+        [".exp.xml"] -> assertLangOkXml opts name
         [".exp.disabled"] -> return ()
         [".exp-disabled"] -> return ()
         [".exp", ".flags"] -> do
@@ -117,7 +123,7 @@ assertEval _opts files =
             flags <- Text.readFile (name ++ ".flags")
             let flags' | Text.last flags == '\n' = Text.init flags
                        | otherwise = flags
-            case Opts.execParserPure Opts.defaultPrefs nixOptionsInfo
+            case Opts.execParserPure Opts.defaultPrefs (nixOptionsInfo time)
                      (fixup (map Text.unpack (Text.splitOn " " flags'))) of
                 Opts.Failure err -> errorWithoutStackTrace $
                     "Error parsing flags from " ++ name ++ ".flags: "
@@ -142,7 +148,8 @@ assertEval _opts files =
 
 assertEvalFail :: FilePath -> Assertion
 assertEvalFail file = catch ?? (\(_ :: SomeException) -> return ()) $ do
-  evalResult <- printNix <$> hnixEvalFile defaultOptions file
+  time <- liftIO getCurrentTime
+  evalResult <- printNix <$> hnixEvalFile (defaultOptions time) file
   evalResult `seq` assertFailure $
       file ++ " should not evaluate.\nThe evaluation result was `"
            ++ evalResult ++ "`."

tests/TestCommon.hs

@@ -4,7 +4,9 @@
 module TestCommon where
 
 import Control.Monad.Catch
+import Control.Monad.IO.Class
 import Data.Text (Text, unpack)
+import Data.Time
 import Nix
 import System.Environment
 import System.IO
@@ -50,13 +52,15 @@ nixEvalFile fp = readProcess "nix-instantiate" ["--eval", fp] ""
 
 assertEvalFileMatchesNix :: FilePath -> Assertion
 assertEvalFileMatchesNix fp = do
-  hnixVal <- (++"\n") . printNix <$> hnixEvalFile defaultOptions fp
+  time <- liftIO getCurrentTime
+  hnixVal <- (++"\n") . printNix <$> hnixEvalFile (defaultOptions time) fp
   nixVal <- nixEvalFile fp
   assertEqual fp nixVal hnixVal
 
 assertEvalMatchesNix :: Text -> Assertion
 assertEvalMatchesNix expr = do
-  hnixVal <- (++"\n") . printNix <$> hnixEvalText defaultOptions expr
+  time <- liftIO getCurrentTime
+  hnixVal <- (++"\n") . printNix <$> hnixEvalText (defaultOptions time) expr
   nixVal <- nixEvalString expr'
   assertEqual expr' nixVal hnixVal
  where