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semantic/semantic-python/test/Directive.hs

128 lines
4.3 KiB
Haskell

{-# LANGUAGE TypeApplications #-}
-- | FileCheck-style directives for testing Core compilers.
module Directive ( Directive (..)
, readDirectivesFromFile
, Expected (..)
, describe
, toProcess
) where
import Control.Applicative
import Control.Monad
import Core.Core (Core)
import Core.Name (Name)
import qualified Core.Parser
import qualified Core.Pretty
import Data.ByteString.Char8 (ByteString)
import qualified Data.ByteString.Char8 as ByteString
import qualified Data.ByteString.Streaming.Char8 as ByteStream
import Data.Text (Text)
import qualified Data.Text as T
import Streaming
import qualified Streaming.Prelude as Stream
import Syntax.Term (Term)
import System.Process
import qualified Text.Parser.Token.Style as Style
import Text.Trifecta (CharParsing, TokenParsing (..))
import qualified Text.Trifecta as Trifecta
import qualified System.Path as Path
import qualified System.Path.PartClass as Path.Class
import Control.Monad.Trans.Resource (ResourceT, runResourceT)
{- |
Directives are parsed from magic comments in test files and
describe to the test suite how to query the results of a given test
case. A directive that looks like this:
@
# CHECK-JQ: has("mach")
@
would, after converting the contents of the file to a Core expression,
dump that expression to JSON and pipe said JSON to @jq -e
'has("mach")@, which will return an error code unless the passed JSON
is a hash containing the @"mach"@ key.
This syntax was inspired by LLVM's
[FileCheck](https://llvm.org/docs/CommandGuide/FileCheck.html). This
approach is less direct than tests that pattern-match over an AST, but
enable us to keep the text of test cases in close proximity to the
assertions we want to make, which improves maintainability
significantly and has been a successful strategy for the LLVM and Rust
projects.
-}
data Directive = JQ ByteString -- | @# CHECK-JQ: expr@
| Tree (Term Core Name) -- | @# CHECK-TREE: core@
| Result Text Expected -- | @# CHECK-RESULT key: expected
| Fails -- | @# CHECK-FAILS@ fails unless translation fails.
deriving (Eq, Show)
-- | Extract all directives from a file.
readDirectivesFromFile :: Path.Class.AbsRel ar => Path.File ar -> IO [Directive]
readDirectivesFromFile
= runResourceT
. Stream.toList_
. Stream.mapM (either perish pure . parseDirective)
. Stream.takeWhile isComment
. Stream.mapped ByteStream.toStrict
. ByteStream.lines
. ByteStream.readFile @(ResourceT IO)
. Path.toString
where
perish s = fail ("Directive parsing error: " <> s)
isComment = (== Just '#') . fmap fst . ByteString.uncons
data Expected
= AString Text
| ABool Bool
| AUnit
deriving (Eq, Show)
describe :: Directive -> String
describe Fails = "<expect failure>"
describe (Tree t) = Core.Pretty.showCore t
describe (JQ b) = ByteString.unpack b
describe (Result t e) = T.unpack t <> ": " <> show e
fails :: CharParsing m => m Directive
fails = Fails <$ Trifecta.string "# CHECK-FAILS"
jq :: (Monad m, CharParsing m) => m Directive
jq = do
void $ Trifecta.string "# CHECK-JQ: "
JQ . ByteString.pack <$> many (Trifecta.noneOf "\n")
tree :: (Monad m, TokenParsing m) => m Directive
tree = do
void $ Trifecta.string "# CHECK-TREE: "
Tree <$> Core.Parser.core
result :: (Monad m, TokenParsing m) => m Directive
result = do
void $ Trifecta.string "# CHECK-RESULT "
key <- Trifecta.ident Style.haskellIdents
void $ Trifecta.symbolic ':'
Result key <$> expected
expected :: TokenParsing m => m Expected
expected = Trifecta.choice
[ AString <$> Trifecta.stringLiteral
, ABool True <$ Trifecta.symbol "#true"
, ABool False <$ Trifecta.symbol "#false"
, AUnit <$ Trifecta.symbol "#unit"
]
directive :: (Monad m, TokenParsing m) => m Directive
directive = Trifecta.choice [ fails, result, jq, tree ]
parseDirective :: ByteString -> Either String Directive
parseDirective = Trifecta.foldResult (Left . show) Right
. Trifecta.parseByteString (directive <* Trifecta.eof) mempty
toProcess :: Directive -> CreateProcess
toProcess (JQ d) = proc "jq" ["-e", ByteString.unpack d]
toProcess x = error ("can't call toProcess on " <> show x)