diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,8 @@
+# Changelog for Shellify
+
+## 0.10.0
+- Add dependency bounds
+
+## 0.9.0
+- Completed usable with good test coverage. I'll await some feedback before declaring a v1.0.0 release.
+
diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,201 @@
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diff --git a/app/Main.hs b/app/Main.hs
new file mode 100644
--- /dev/null
+++ b/app/Main.hs
@@ -0,0 +1,13 @@
+module Main where
+
+import Data.Text (pack)
+import Shellify (runShellify)
+import System.Environment (getArgs, getProgName)
+
+main :: IO ()
+main = do
+  progName <- pack <$> getProgName
+  getTextArgs
+    >>= runShellify . (<>) [progName]
+
+getTextArgs = fmap pack <$> getArgs
diff --git a/shellify.cabal b/shellify.cabal
new file mode 100644
--- /dev/null
+++ b/shellify.cabal
@@ -0,0 +1,72 @@
+cabal-version:      3.0
+name:               shellify
+version:            0.10.0
+
+author: Daniel Rolls
+maintainer: daniel.rolls.27@googlemail.com
+license: Apache-2.0
+license-files: LICENSE
+copyright: (c) 2023 Daniel Rolls
+synopsis: A tool for generating shell.nix files
+description:
+        Please see the README on GitHub at <https://github.com/danielrolls/shellify>
+category: Packaging
+extra-source-files:
+        CHANGELOG.md
+        test/outputs/*.nix
+
+common deps
+    default-language: GHC2021
+    build-depends:
+        base >=4.16.4.0 && <4.17,
+        raw-strings-qq >=1.1 && <1.2,
+        text >=1.2.5.0 && <1.3
+
+    default-extensions:
+        LambdaCase
+        OverloadedStrings
+        QuasiQuotes
+   
+library
+    import: deps
+    exposed-modules:
+        Constants
+        FlakeTemplate
+        Options
+        Shellify
+        ShellifyTemplate
+        TemplateGeneration
+        Paths_shellify
+    autogen-modules:
+        Paths_shellify
+    hs-source-dirs: src
+    build-depends:
+        containers >=0.6.5.1 && <0.7,
+        data-default-class >=0.1.2.0 && <0.2,
+        directory >=1.3.6.2 && <1.4,
+        extra >=1.7.13 && <1.8,
+        HStringTemplate >=0.8.8 && <0.9,
+        mtl >=2.2.2 && <2.3,
+        shake >=0.19.7 && <0.20,
+        unordered-containers >=0.2.19.1 && <0.3
+
+executable shellify
+    import: deps
+    main-is: Main.hs
+    build-depends:    
+        shellify >=0
+    hs-source-dirs: app
+
+test-suite haskelltest-test
+    import: deps
+    type: exitcode-stdio-1.0
+    main-is: Spec.hs
+    hs-source-dirs: test
+    other-modules:
+        Paths_shellify
+    ghc-options: -threaded -rtsopts -with-rtsopts=-N
+    build-depends:
+        hspec >=2.9.7 && <2.10,
+        hspec-core >=2.9.7 && <2.10,
+        shellify >=0
+
diff --git a/src/Constants.hs b/src/Constants.hs
new file mode 100644
--- /dev/null
+++ b/src/Constants.hs
@@ -0,0 +1,33 @@
+module Constants where
+
+import Data.Text (Text())
+import Text.RawString.QQ (r)
+
+helpText :: Text -> Text
+helpText progName = "USAGE: " <> progName <> [r| -p [PACKAGES] 
+       |] <> progName <> [r| [--with-flakes] [PACKAGES]
+
+Pass nix-shell arguments to nix-shellify to have it generate a shell.nix in
+the current directory. You can then just run nix shell or nix-shell in that
+directory to have those packages in your environment. To run nix commands
+you must first install Nix.
+
+Options
+
+    -p / --packages
+    Specify packages for nix-shell compatability
+
+    --command / --run
+    Command to run after creating the shell
+
+    --with-flake
+    When using the command in a flake-like style use this switch to have a
+    flake.nix created in addition to a shell.nix. Highly recommended to ensure
+    the versions of dependencies are kept for reproducibility and so that
+    shells are cached to load faster.
+|]
+
+noPackagesError = [r|I can't write out a shell file without any packages specified.
+Try 'nix-shellify --help' for more information.|] :: Text
+
+pkgsDecl var repo = var <> [r| = if builtins.hasAttr "packages" |] <> repo <> [r| then |] <> repo <> [r|.packages.${system} else ( if builtins.hasAttr "legacyPackages" |] <> repo <> [r| then |] <> repo <> [r|.legacyPackages.${system} else |] <> repo <> [r|);|]
diff --git a/src/FlakeTemplate.hs b/src/FlakeTemplate.hs
new file mode 100644
--- /dev/null
+++ b/src/FlakeTemplate.hs
@@ -0,0 +1,27 @@
+module FlakeTemplate where
+
+import Text.RawString.QQ (r)
+
+
+flakeTemplate = [r|{
+  description = "my project description";
+
+  inputs = {
+
+    flake-utils.url = "github:numtide/flake-utils";
+    $repo_inputs;separator='
+    '$
+
+  };
+
+  outputs = { self, $repos;separator=', '$, flake-utils }:
+    flake-utils.lib.eachDefaultSystem
+      (system:
+        let $pkgs_decls;separator='
+            '$
+        in
+        {
+          devShells.default = import ./shell.nix { $shell_args;separator=' '$ };
+        }
+      );
+}|]
diff --git a/src/Options.hs b/src/Options.hs
new file mode 100644
--- /dev/null
+++ b/src/Options.hs
@@ -0,0 +1,105 @@
+module Options (Package(..), Options(..), def, Packages, options) where
+import Prelude hiding (takeWhile, writeFile)
+
+import Constants
+import FlakeTemplate
+import ShellifyTemplate
+
+import Control.Applicative ((<|>))
+import Control.Arrow ((+++))
+import Control.Monad (when)
+import Data.Bool (bool)
+import Data.Default.Class (Default(def))
+import Data.List (find, sort)
+import Data.Maybe (fromMaybe)
+import Data.Text (isInfixOf, isPrefixOf, pack, replace, splitOn, stripPrefix, takeWhile, Text(), unpack)
+import Data.Text.IO (hPutStrLn, writeFile)
+import qualified Data.Text.IO as Text
+import GHC.IO.Exception (ExitCode(ExitSuccess, ExitFailure))
+import System.Directory (doesPathExist)
+import System.Exit (exitWith)
+import System.IO (stderr)
+import Text.StringTemplate (newSTMP, render, setAttribute, StringTemplate)
+
+type Package = Text
+type Packages = [ Package ]
+data Options = Options {
+    packages :: Packages
+  , command :: Maybe Text
+  , generateFlake :: Bool
+}
+
+data OptionsParser = OptionsParser [Text] -- remainingOptions
+                                   (Either Text (Options -> Options)) -- result
+
+options :: Text -> [Text] -> Either Text Options
+options progName args =
+  let optionsHandler | hasShellArg args = newStyleOption
+                     | otherwise = oldStyleOption
+      shellArgFilter | hasShellArg args = filter (/= "shell")
+                     | otherwise = id
+      optionsCaller f = worker 
+       where worker (OptionsParser [] t) = t
+             worker (OptionsParser (hd:tl) res) =
+               let (OptionsParser newRemaining newRes) = f hd tl
+               in worker $ OptionsParser newRemaining ((.) <$> newRes <*> res)
+
+      screenForNoPackages (Right opts) | null (packages opts) = Left noPackagesError
+      screenForNoPackages anyThingElse = anyThingElse
+      initialArgumentsToParse = shellArgFilter args
+      initialModifier = Right $ if hasShellArg args then setFlakeGeneration else id
+      initialOptionParser = OptionsParser initialArgumentsToParse initialModifier
+  in screenForNoPackages $ ($ def) <$> optionsCaller optionsHandler initialOptionParser
+
+  where oldStyleOption :: Text -> [Text] -> OptionsParser
+        oldStyleOption "-p" = handlePackageSwitch
+        oldStyleOption "--packages" = handlePackageSwitch
+        oldStyleOption opt = baseOption opt
+        newStyleOption "-p" = returnError "-p not supported with new style commands"
+        newStyleOption "--packages" = returnError "--packages not supported with new style commands"
+        newStyleOption arg | isSwitch arg = baseOption arg
+                           | otherwise = transformOptionsWith $ appendPackages [arg]
+        baseOption :: Text -> [Text] -> OptionsParser
+        baseOption "-h" = returnError $ helpText progName
+        baseOption "--help" = returnError $ helpText progName
+        baseOption "--command" = handleCommandSwitch
+        baseOption "--run" = handleCommandSwitch
+        baseOption "--with-flake" = transformOptionsWith setFlakeGeneration
+        baseOption _ = transformOptionsWith id
+        --doNothing = transformOptionsWith id
+        transformOptionsWith fun wds = OptionsParser wds (Right fun)
+        handlePackageSwitch wds = let (pkgs, remainingOptions) = consumePackageArgs wds
+                                  in transformOptionsWith (appendPackages pkgs) remainingOptions
+        handleCommandSwitch (hd:tl) | isSwitch hd
+                                    = returnError "Argument missing to switch" tl
+                                    | otherwise
+                                    = transformOptionsWith (setCommand hd) tl
+        handleCommandSwitch [] = returnError "Argument missing to switch" []
+
+        appendPackages ps opts = opts{packages=ps ++ packages opts}
+        setCommand cmd opts = opts{command=Just cmd}
+        setFlakeGeneration opts = opts{generateFlake=True}
+        returnError errorText remaining = OptionsParser remaining $ Left errorText
+
+consumePackageArgs :: [Text] -> (Packages, [Text])
+consumePackageArgs = worker []
+  where worker pkgs [] = (pkgs, [])
+        worker pkgs options@(hd:_) | isSwitch hd
+                                   = (pkgs, options)
+        worker pkgs (hd:tl) = worker (hd:pkgs) tl
+
+hasShellArg [] = False
+hasShellArg ("shell":_) = True
+hasShellArg (hd:tl) | isSwitch hd = hasShellArg tl
+                    | otherwise = False
+
+isSwitch = isPrefixOf "-"
+
+instance Default Options where
+  def = Options [] Nothing False
+
+instance Eq Options where
+  a == b =  isEqual command
+         && isEqual (sort . packages)
+         && isEqual generateFlake
+    where isEqual f = f a == f b
diff --git a/src/Shellify.hs b/src/Shellify.hs
new file mode 100644
--- /dev/null
+++ b/src/Shellify.hs
@@ -0,0 +1,71 @@
+module Shellify (parseOptionsAndCalculateExpectedFiles, runShellify) where
+
+import Prelude hiding (writeFile)
+import Constants
+import FlakeTemplate
+import Options
+import ShellifyTemplate
+import TemplateGeneration
+
+import Control.Monad (when, (>=>))
+import Data.Bool (bool)
+import Data.Text (pack, Text(), unpack)
+import Data.Text.IO (hPutStrLn, writeFile)
+import qualified Data.Text.IO as Text
+import GHC.IO.Exception (ExitCode(ExitSuccess, ExitFailure))
+import System.Directory (doesPathExist)
+import System.Exit (exitWith)
+import System.IO (stderr)
+
+createAFile (name, content) = do extCde <- createFile (unpack name) content
+                                 when (extCde /= ExitSuccess)
+                                   $ exitWith extCde
+
+
+runShellify :: [Text] -> IO ()
+runShellify(pName:args) = getRegistryDB
+             >>= either
+                   ((printErrorAndReturnFailure . ("Error calling nix registry: " <>) ) >=> exitWith)
+                   (\registryDB -> either printError
+                                          (mapM_ createAFile)
+                                          $ parseOptionsAndCalculateExpectedFiles registryDB pName args)
+
+
+parseOptionsAndCalculateExpectedFiles :: Text -> Text -> [Text] -> Either Text [(Text,Text)]
+parseOptionsAndCalculateExpectedFiles registry programName =
+  fmap
+    (\opts ->
+        ("shell.nix", generateShellDotNixText opts)
+      : maybe
+            []
+            (pure . ("flake.nix",))
+            (generateFlakeText registry opts))
+  . options programName
+
+createFile :: FilePath -> Text -> IO ExitCode
+createFile fileName expectedContents = do
+  fileContents <-     doesPathExist fileName
+                  >>= bool
+                       (return Nothing)
+                       (Just <$> Text.readFile fileName)
+  printError $ actionDescription (pack fileName) expectedContents fileContents
+  when (shouldGenerateNewFile fileContents)
+    $ writeFile fileName expectedContents
+  return $ returnCode expectedContents fileContents
+
+actionDescription :: Text -> Text -> Maybe Text -> Text
+actionDescription fName _ Nothing = fName <> " does not exist. Creating one"
+actionDescription fName a (Just b) | a == b = "The existing " <> fName <> " is good already"
+actionDescription fName _ _ = "A " <> fName <> " exists already. Delete it or move it and try again"
+
+returnCode :: Text -> Maybe Text -> ExitCode
+returnCode _ Nothing = ExitSuccess
+returnCode a (Just b) | a == b = ExitSuccess
+returnCode _ _ = ExitFailure 1
+
+shouldGenerateNewFile :: Maybe Text -> Bool
+shouldGenerateNewFile = (== Nothing)
+
+printErrorAndReturnFailure err = printError err >> return (ExitFailure 1)
+printError = hPutStrLn stderr
+
diff --git a/src/ShellifyTemplate.hs b/src/ShellifyTemplate.hs
new file mode 100644
--- /dev/null
+++ b/src/ShellifyTemplate.hs
@@ -0,0 +1,20 @@
+module ShellifyTemplate where
+
+import Text.RawString.QQ (r)
+
+shellifyTemplate = [r|{ $parameters;separator=', '$ }:
+
+pkgs.mkShell {
+
+  buildInputs = [
+    $build_inputs;separator='
+    '$
+  ];
+$if(shell_hook)$
+
+  shellHook = ''
+    $shell_hook$
+  '';
+$endif$
+}
+|]
diff --git a/src/TemplateGeneration.hs b/src/TemplateGeneration.hs
new file mode 100644
--- /dev/null
+++ b/src/TemplateGeneration.hs
@@ -0,0 +1,112 @@
+module TemplateGeneration (generateShellDotNixText, generateFlakeText, getRegistryDB) where
+
+import Prelude hiding (lines)
+
+import Constants
+import FlakeTemplate
+import Options
+import ShellifyTemplate
+
+import Data.Bool (bool)
+import Data.List (find, sort)
+import Data.List.Extra ((!?))
+import Data.Maybe (catMaybes, fromMaybe)
+import Data.Set (fromList, toList)
+import Data.Text (isInfixOf, isPrefixOf, lines, pack, splitOn, Text())
+import Development.Shake.Command (cmd, Exit(Exit), Stderr(Stderr), Stdout(Stdout))
+import System.Exit (ExitCode (ExitSuccess))
+import Text.StringTemplate (newSTMP, render, setAttribute)
+
+generateFlakeText :: Text -> Options -> Maybe Text
+generateFlakeText db Options{packages=packages, generateFlake=shouldGenerateFlake} =
+  bool
+    Nothing
+    (Just $ render
+          $ setAttribute "repo_inputs" repoInputs
+          $ setAttribute "repos" repos
+          $ setAttribute "pkgs_decls" pkgsDecls
+          $ setAttribute "shell_args" shellArgs
+          $ newSTMP flakeTemplate)
+    shouldGenerateFlake
+  where repos = uniq $ getPackageRepo <$> sort packages
+        repoVars = getPackageRepoVarName <$> repos
+        repoInputs = repoInput <$> repos
+        repoInputLine repoName url = repoName <> ".url = \"" <> url <> "\";"
+        repoInput repoName = repoInputLine repoName .
+          either
+            (error "Unexpected output from nix registry call: " <>)
+            (fromMaybe "PLEASE ENTER input here")
+            . findFlakeRepoUrl db $ repoName
+        pkgsVar = (<> "Pkgs")
+        pkgsVars = pkgsVar <$> repos
+        pkgsDecls = (\repo -> pkgsDecl (pkgsVar repo) repo) <$> repos
+        shellArgs = (\(a,b) -> a <> "=" <> b <> ";") <$> zip repoVars pkgsVars 
+
+generateShellDotNixText :: Options -> Text
+generateShellDotNixText Options{packages=packages, command=command} =
+  render
+  $ setAttribute "build_inputs" pkgs
+  $ setAttribute "parameters" parameters
+  $ maybe id
+          (setAttribute "shell_hook")
+          command
+  $ newSTMP shellifyTemplate
+  where pkgs = generateBuildInput <$> sort packages
+        parameters = uniq $ generateParameters <$> sort packages
+        generateBuildInput input = (toImportVar . getPackageRepo) input <> "." <> getPackageName input
+
+getPackageRepo input | "#" `isInfixOf` input
+                        = head $ splitOn "#" input
+                     | otherwise
+                        = "nixpkgs"
+
+getPackageName input | "#" `isInfixOf` input
+                        = head $ tail $ splitOn "#" input
+                     | otherwise
+                        = input
+
+toImportVar var | var == "nixpkgs"
+                  = "pkgs"
+                | otherwise
+                  = var
+
+getPackageRepoVarName "nixpkgs" = "pkgs"
+getPackageRepoVarName a = a
+
+generateParameters :: Package -> Text
+generateParameters package | "#" `isInfixOf` package
+                           && not ("nixpkgs#" `isPrefixOf` package)
+                           = getPackageRepo package
+generateParameters _ = "pkgs ? import <nixpkgs> {}"
+
+uniq :: Ord a => [a] -> [a]
+uniq = toList . fromList
+
+getRegistryDB :: IO (Either Text Text)
+getRegistryDB =
+     do (Stdout out, Stderr err, Exit ex) <- cmd
+          ("nix --extra-experimental-features nix-command --extra-experimental-features flakes registry list" :: String)
+        return $ bool (Left $ pack err)
+                      (Right $ pack out)
+                      (ex == ExitSuccess)
+
+findFlakeRepoUrl :: Text -> Text -> Either Text (Maybe Text)
+findFlakeRepoUrl haystack needle =
+       fmap repoUrl . find ((needle ==) . repoName) . catMaybes <$> mapM getFlakeRepo (lines haystack)
+
+data FlakeRepo = FlakeRepo {
+    repoName :: Text
+  , repoUrl :: Text
+}
+
+getFlakeRepo :: Text -> Either Text (Maybe FlakeRepo)
+getFlakeRepo line = let expectedField = maybe (Left "unexepected nix registry command format")
+                                              Right
+                                        . (!?) (splitOn " " line)
+                        urlField = expectedField 2
+                        splitRepoField = splitOn ":" <$> expectedField 1
+                        potentialFlakeName ["flake", b] = Just b
+                        potentialFlakeName _ = Nothing
+                        f x y = (`FlakeRepo` y) <$> potentialFlakeName x
+                     in f <$> splitRepoField <*> urlField
+
diff --git a/test/Spec.hs b/test/Spec.hs
new file mode 100644
--- /dev/null
+++ b/test/Spec.hs
@@ -0,0 +1,118 @@
+import Test.Hspec (describe, hspec, it, shouldBe)
+
+import Options
+import TestHelpers
+
+
+main = hspec $ do
+
+  describe "When passing option combinations" $ do
+    it "should print a message saying no package is specified when no argument is supplied" $
+      shellifyWithArgs ""
+        `shouldReturnSubstring`
+      "without any packages specified"
+
+    it "should complain if no package is specified" $
+      shellifyWithArgs "nipkgs#cowsay"
+        `shouldReturnSubstring`
+      "without any packages specified"
+
+    it "should show help text when requested" $ do
+      shellifyWithArgs "-h"
+          `shouldReturnSubstring` "USAGE:"
+      shellifyWithArgs "--help"
+          `shouldReturnSubstring` "USAGE:"
+
+    it "should not support -p with shell" $ do
+      shellifyWithArgs "shell -p cowsay"
+         `shouldBe`
+        Left "-p not supported with new style commands"
+      shellifyWithArgs "shell nixpkgs#python --packages foo nixpkgs#cowsay"
+         `shouldBe`
+        Left "--packages not supported with new style commands"
+
+    it "should allow a simple command to be specified with a package" $
+      theOptions "-p python --command cowsay"
+        `shouldBe`
+      Right def{packages=["python"], command=Just "cowsay"}
+
+    it "should allow a simple command to be specified before a package" $
+      theOptions "--run cowsay -p python"
+        `shouldBe`
+      Right def{packages=["python"], command=Just "cowsay"}
+
+    it "should allow a simple command to be specified before and after a package" $
+      theOptions "-p cowsay --command cowsay -p python"
+        `shouldBe`
+      Right def{packages=[ "cowsay", "python" ], command=Just "cowsay"}
+
+    it "Should fail if command has no argument" $ do
+      shellifyWithArgs "--command -p python"
+          `shouldReturnSubstring` "Argument missing to switch"
+      shellifyWithArgs "--command"
+          `shouldReturnSubstring` "Argument missing to switch"
+
+    it "should be able to specify one program to install after other arguments" $
+      "foo -p python"
+        `shouldResultInPackages`
+      [ "python" ]
+
+    it "should support multiple packages passed to -p" $
+      "-p python cowsay"
+        `shouldResultInPackages`
+      [ "cowsay", "python" ]
+
+    it "should only accept packages up to the next switch" $
+      "-p python --arg x 2"
+        `shouldResultInPackages`
+      [ "python" ]
+
+    it "should support multiple adjacent -p switches" $
+      "-p python -p cowsay"
+        `shouldResultInPackages`
+      [ "python", "cowsay" ]
+
+    it "should support separated -p switches" $
+      "-p cowsay --foo -p python"
+        `shouldResultInPackages`
+      [ "cowsay", "python" ]
+
+    it "should support long switches" $
+      "--packages cowsay"
+        `shouldResultInPackages`
+      [ "cowsay" ]
+
+    it "should support new shell commands" $
+      theOptions "shell nixpkgs#python nixpkgs#cowsay"
+        `shouldBe`
+      Right def{packages=[ "nixpkgs#python", "nixpkgs#cowsay" ], generateFlake=True}
+
+  describe "when two buildInputs are required from two sources" $
+    shellifyWithArgs "--with-flake shell foo#cowsay nixpkgs#python"
+      `shouldReturnShellAndFlakeTextDefinedBy`
+    "inputs-from-know-and-unknown-sources"
+
+  describe "when using 2 simple buildInputs from one source" $
+    shellifyWithArgs "shell --with-flake python cowsay"
+      `shouldReturnShellAndFlakeTextDefinedBy`
+    "two-nixpkgs-inputs"
+
+  describe "when pulling from 2 different known sources" $
+    shellifyWithArgs "shell nixpkgs#python blender-bin#blender_3_5"
+      `shouldReturnShellAndFlakeTextDefinedBy`
+    "inputs-from-different-registries"
+
+  describe "when working with 2 nixkgs buildInputs" $
+      shellifyWithArgs "shell nixpkgs#python nixpkgs#cowsay"
+        `shouldReturnShellTextDefinedBy`
+      "two-nixpkgs-inputs"
+
+  describe "when working with multiple repos for known and unknown sources" $
+      shellifyWithArgs "shell nixpkgs#python foo#cowsay"
+        `shouldReturnShellTextDefinedBy`
+      "multiple-repository-sources"
+
+  describe "when a command is specified" $
+      shellifyWithArgs "-p python -p cowsay --command cowsay"
+        `shouldReturnShellTextDefinedBy`
+      "two-build-inputs-and-command"
diff --git a/test/outputs/inputs-from-different-registries-flake.nix b/test/outputs/inputs-from-different-registries-flake.nix
new file mode 100644
--- /dev/null
+++ b/test/outputs/inputs-from-different-registries-flake.nix
@@ -0,0 +1,22 @@
+{
+  description = "my project description";
+
+  inputs = {
+
+    flake-utils.url = "github:numtide/flake-utils";
+    blender-bin.url = "github:edolstra/nix-warez?dir=blender";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+
+  };
+
+  outputs = { self, blender-bin, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem
+      (system:
+        let blender-binPkgs = if builtins.hasAttr "packages" blender-bin then blender-bin.packages.${system} else ( if builtins.hasAttr "legacyPackages" blender-bin then blender-bin.legacyPackages.${system} else blender-bin);
+            nixpkgsPkgs = if builtins.hasAttr "packages" nixpkgs then nixpkgs.packages.${system} else ( if builtins.hasAttr "legacyPackages" nixpkgs then nixpkgs.legacyPackages.${system} else nixpkgs);
+        in
+        {
+          devShells.default = import ./shell.nix { blender-bin=blender-binPkgs; pkgs=nixpkgsPkgs; };
+        }
+      );
+}
diff --git a/test/outputs/inputs-from-different-registries-shell.nix b/test/outputs/inputs-from-different-registries-shell.nix
new file mode 100644
--- /dev/null
+++ b/test/outputs/inputs-from-different-registries-shell.nix
@@ -0,0 +1,10 @@
+{ blender-bin, pkgs ? import <nixpkgs> {} }:
+
+pkgs.mkShell {
+
+  buildInputs = [
+    blender-bin.blender_3_5
+    pkgs.python
+  ];
+
+}
diff --git a/test/outputs/inputs-from-know-and-unknown-sources-flake.nix b/test/outputs/inputs-from-know-and-unknown-sources-flake.nix
new file mode 100644
--- /dev/null
+++ b/test/outputs/inputs-from-know-and-unknown-sources-flake.nix
@@ -0,0 +1,22 @@
+{
+  description = "my project description";
+
+  inputs = {
+
+    flake-utils.url = "github:numtide/flake-utils";
+    foo.url = "PLEASE ENTER input here";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+
+  };
+
+  outputs = { self, foo, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem
+      (system:
+        let fooPkgs = if builtins.hasAttr "packages" foo then foo.packages.${system} else ( if builtins.hasAttr "legacyPackages" foo then foo.legacyPackages.${system} else foo);
+            nixpkgsPkgs = if builtins.hasAttr "packages" nixpkgs then nixpkgs.packages.${system} else ( if builtins.hasAttr "legacyPackages" nixpkgs then nixpkgs.legacyPackages.${system} else nixpkgs);
+        in
+        {
+          devShells.default = import ./shell.nix { foo=fooPkgs; pkgs=nixpkgsPkgs; };
+        }
+      );
+}
diff --git a/test/outputs/inputs-from-know-and-unknown-sources-shell.nix b/test/outputs/inputs-from-know-and-unknown-sources-shell.nix
new file mode 100644
--- /dev/null
+++ b/test/outputs/inputs-from-know-and-unknown-sources-shell.nix
@@ -0,0 +1,10 @@
+{ foo, pkgs ? import <nixpkgs> {} }:
+
+pkgs.mkShell {
+
+  buildInputs = [
+    foo.cowsay
+    pkgs.python
+  ];
+
+}
diff --git a/test/outputs/multiple-repository-sources-shell.nix b/test/outputs/multiple-repository-sources-shell.nix
new file mode 100644
--- /dev/null
+++ b/test/outputs/multiple-repository-sources-shell.nix
@@ -0,0 +1,10 @@
+{ foo, pkgs ? import <nixpkgs> {} }:
+
+pkgs.mkShell {
+
+  buildInputs = [
+    foo.cowsay
+    pkgs.python
+  ];
+
+}
diff --git a/test/outputs/two-build-inputs-and-command-shell.nix b/test/outputs/two-build-inputs-and-command-shell.nix
new file mode 100644
--- /dev/null
+++ b/test/outputs/two-build-inputs-and-command-shell.nix
@@ -0,0 +1,14 @@
+{ pkgs ? import <nixpkgs> {} }:
+
+pkgs.mkShell {
+
+  buildInputs = [
+    pkgs.cowsay
+    pkgs.python
+  ];
+
+  shellHook = ''
+    cowsay
+  '';
+
+}
diff --git a/test/outputs/two-nixpkgs-inputs-flake.nix b/test/outputs/two-nixpkgs-inputs-flake.nix
new file mode 100644
--- /dev/null
+++ b/test/outputs/two-nixpkgs-inputs-flake.nix
@@ -0,0 +1,20 @@
+{
+  description = "my project description";
+
+  inputs = {
+
+    flake-utils.url = "github:numtide/flake-utils";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem
+      (system:
+        let nixpkgsPkgs = if builtins.hasAttr "packages" nixpkgs then nixpkgs.packages.${system} else ( if builtins.hasAttr "legacyPackages" nixpkgs then nixpkgs.legacyPackages.${system} else nixpkgs);
+        in
+        {
+          devShells.default = import ./shell.nix { pkgs=nixpkgsPkgs; };
+        }
+      );
+}
diff --git a/test/outputs/two-nixpkgs-inputs-shell.nix b/test/outputs/two-nixpkgs-inputs-shell.nix
new file mode 100644
--- /dev/null
+++ b/test/outputs/two-nixpkgs-inputs-shell.nix
@@ -0,0 +1,10 @@
+{ pkgs ? import <nixpkgs> {} }:
+
+pkgs.mkShell {
+
+  buildInputs = [
+    pkgs.cowsay
+    pkgs.python
+  ];
+
+}