diff --git a/cabal.project.local b/cabal.project.local
--- a/cabal.project.local
+++ b/cabal.project.local
@@ -1,6 +1,2 @@
 constraints: hspec-dirstream +development
-with-compiler: ghc-8.2.2
-tests: True
 documentation: True
-haddock-hoogle: True
-haddock-internal: True
diff --git a/hspec-dirstream.cabal b/hspec-dirstream.cabal
--- a/hspec-dirstream.cabal
+++ b/hspec-dirstream.cabal
@@ -1,62 +1,77 @@
-name:                hspec-dirstream
-version:             0.4.0.0
-synopsis:            Helper functions to simplify adding integration tests.
-description:         This package uses [hspec](http://hackage.haskell.org/package/hspec) and [dirstream](http://hackage.haskell.org/package/dirstream) to provide easy-to-use functions for integration tests.
-homepage:            https://hub.darcs.net/vmchale/hspec-dirstream
-license:             BSD3
-license-file:        LICENSE
-author:              Vanessa McHale
-maintainer:          vamchale@gmail.com
-copyright:           Copyright: (c) 2018 Vanessa McHale
-category:            Testing, Development
-build-type:          Simple
-extra-doc-files:     README.md
-data-files:          test/data/*.hs
-                   , test/data/*.out
-extra-source-files:  stack.yaml
-                   , cabal.project.local
-cabal-version:       >=1.18
+cabal-version: 1.18
+name: hspec-dirstream
+version: 0.5.0.0
+license: BSD3
+license-file: LICENSE
+copyright: Copyright: (c) 2018 Vanessa McHale
+maintainer: vamchale@gmail.com
+author: Vanessa McHale
+homepage: https://hub.darcs.net/vmchale/hspec-dirstream
+synopsis: Helper functions to simplify adding integration tests.
+description:
+    This package uses [hspec](http://hackage.haskell.org/package/hspec) and [dirstream](http://hackage.haskell.org/package/dirstream) to provide easy-to-use functions for integration tests.
+category: Testing, Development
+build-type: Simple
+data-files:
+    test/data/*.hs
+    test/data/*.out
+extra-source-files:
+    stack.yaml
+    cabal.project.local
+extra-doc-files: README.md
 
-Flag development {
-  Description: Enable `-Werror`
-  manual: True
-  default: False
-}
+source-repository head
+    type: darcs
+    location: https://hub.darcs.net/vmchale/hspec-dirstream
 
+flag development
+    description:
+        Enable `-Werror`
+    default: False
+    manual: True
+
 library
-  hs-source-dirs:      src
-  exposed-modules:     Test.Hspec.Dirstream
-  build-depends:       base >= 4.7 && < 5
-                     , hspec
-                     , dirstream
-                     , pipes
-                     , pipes-safe
-                     , filepath
-                     , hspec-core
-                     , system-filepath
-                     , text
-  default-language:    Haskell2010
-  if flag(development)
-    ghc-options:       -Werror
-  if impl(ghc >= 8.0)
-    ghc-options:       -Wincomplete-uni-patterns -Wincomplete-record-updates -Wcompat
-  ghc-options:         -Wall
+    exposed-modules:
+        Test.Hspec.Dirstream
+    hs-source-dirs: src
+    default-language: Haskell2010
+    ghc-options: -Wall
+    build-depends:
+        base >=4.7 && <5,
+        hspec -any,
+        dirstream -any,
+        pipes -any,
+        pipes-safe -any,
+        filepath -any,
+        hspec-core -any,
+        system-filepath -any,
+        text -any,
+        bytestring -any
+    
+    if flag(development)
+        ghc-options: -Werror
+    
+    if impl(ghc >=8.0)
+        ghc-options: -Wincomplete-uni-patterns -Wincomplete-record-updates
+                     -Wcompat
 
 test-suite hspec-dirstream-test
-  type:                exitcode-stdio-1.0
-  hs-source-dirs:      test
-  main-is:             Spec.hs
-  build-depends:       base
-                     , hspec-dirstream
-                     , hspec
-  if flag(development)
-    if impl(ghc >= 8.0)
-      ghc-options:     -Werror
-  if impl(ghc >= 8.0)
-    ghc-options:       -Wincomplete-uni-patterns -Wincomplete-record-updates -Wcompat
-  ghc-options:         -threaded -rtsopts -with-rtsopts=-N -Wall
-  default-language:    Haskell2010
-
-source-repository head
-  type:     darcs
-  location: https://hub.darcs.net/vmchale/hspec-dirstream
+    type: exitcode-stdio-1.0
+    main-is: Spec.hs
+    hs-source-dirs: test
+    default-language: Haskell2010
+    ghc-options: -threaded -rtsopts -with-rtsopts=-N -Wall
+    build-depends:
+        base -any,
+        hspec-dirstream -any,
+        hspec -any,
+        bytestring -any
+    
+    if flag(development)
+        
+        if impl(ghc >=8.0)
+            ghc-options: -Werror
+    
+    if impl(ghc >=8.0)
+        ghc-options: -Wincomplete-uni-patterns -Wincomplete-record-updates
+                     -Wcompat
diff --git a/src/Test/Hspec/Dirstream.hs b/src/Test/Hspec/Dirstream.hs
--- a/src/Test/Hspec/Dirstream.hs
+++ b/src/Test/Hspec/Dirstream.hs
@@ -10,12 +10,14 @@
     , testFilesIO
     , testFilesErr
     , testFilesPredicate
+    , testFilesPredicateBS
     , testPaths
     -- * Helper functions for dealing with file extensions
     , F.extension
     , Test.Hspec.Dirstream.hasExtension
     ) where
 
+import qualified Data.ByteString.Lazy      as BSL
 import           Data.DirStream
 import           Data.Text                 (Text)
 import qualified Filesystem.Path.CurrentOS as F
@@ -81,6 +83,15 @@
                    -> SpecWith ()
 testFilesPredicate dir p f pr = runSafeT $ runEffect $ paths dir p >-> mapS (testFilePredicate f pr)
 
+-- | Same as @testFilesPredicate@, but reads the file as a 'ByteString'.
+testFilesPredicateBS :: (Show a, Eq a)
+                    => FilePath
+                    -> (F.FilePath -> Bool)
+                    -> (BSL.ByteString -> a)
+                    -> (a -> Bool)
+                    -> SpecWith ()
+testFilesPredicateBS dir p f pr = runSafeT $ runEffect $ paths dir p >-> mapS (testFilePredicateBS f pr)
+
 -- | Run an action on a file path.
 testPathWorks :: (FilePath -> IO ()) -> FilePath -> SpecWith ()
 testPathWorks fun path = it path $
@@ -97,6 +108,11 @@
 -- file.
 testFilesErr :: (Show b, Eq b) => FilePath -> (F.FilePath -> Bool) -> (String -> Either String b) -> SpecWith ()
 testFilesErr dir p f = runSafeT $ runEffect $ paths dir p >-> mapS (testFileErr f)
+
+testFilePredicateBS :: (Eq a, Show a) => (BSL.ByteString -> a) -> (a -> Bool) -> String -> SpecWith ()
+testFilePredicateBS fun p f = it f $ do
+    sample <- BSL.readFile f
+    fun sample `shouldSatisfy` p
 
 testFilePredicate :: (Eq a, Show a) => (String -> a) -> (a -> Bool) -> String -> SpecWith ()
 testFilePredicate fun p f = it f $ do
diff --git a/test/Spec.hs b/test/Spec.hs
--- a/test/Spec.hs
+++ b/test/Spec.hs
@@ -1,10 +1,7 @@
-{-# LANGUAGE CPP               #-}
 {-# LANGUAGE OverloadedStrings #-}
 
-#if __GLASGOW_HASKELL__ <= 708
-import           Control.Applicative
-#endif
 import           Control.Monad
+import qualified Data.ByteString.Lazy as BSL
 import           Test.Hspec
 import           Test.Hspec.Dirstream
 
@@ -16,5 +13,7 @@
             testFilesIO "test/data" (hasExtension "hs") (pure . tail)
     describe "testFilesPredicate" $
             testFilesPredicate "test/data" (hasExtension "hs") tail ((>= 0) . length)
+    describe "testFilesPredicateBS" $
+            testFilesPredicateBS "test/data" (hasExtension "hs") id ((>= 0) . BSL.length)
     describe "testPaths" $
             testPaths "test/data" (hasExtension "hs") (void . readFile)