nbstripout: fix tests

pkgs/applications/version-management/nbstripout/default.nix

@@ -2,6 +2,7 @@
   lib,
   python3,
   fetchPypi,
+  fetchFromGitHub,
   coreutils,
   gitMinimal,
   mercurial,
@@ -16,11 +17,12 @@ python3.pkgs.buildPythonApplication rec {
     hash = "sha256-6qyLa05yno3+Hl3ywPi6RKvFoXplRI8EgBQfgL4jC7E=";
   };
 
-  # for some reason, darwin uses /bin/sh echo native instead of echo binary, so
-  # force using the echo binary
-  postPatch = ''
-    substituteInPlace tests/test-git.t --replace "echo" "${coreutils}/bin/echo"
-  '';
+  testAssets = fetchFromGitHub {
+    owner = "kynan";
+    repo = "nbstripout";
+    rev = "${version}";
+    hash = "sha256-OSJLrWkYQIhcdyofS3Bo39ppsU6K3A4546UKB8Q1GGg=";
+  };
 
   propagatedBuildInputs = with python3.pkgs; [
     nbformat
@@ -33,14 +35,21 @@ python3.pkgs.buildPythonApplication rec {
       mercurial
     ]
     ++ (with python3.pkgs; [
-      pytest-cram
       pytestCheckHook
     ]);
 
+  checkInputs = [
+    testAssets
+  ];
+
   preCheck = ''
     export HOME=$(mktemp -d)
     export PATH=$out/bin:$PATH
     git config --global init.defaultBranch main
+
+    cp -r --no-preserve=mode,ownership ${testAssets}/tests/e2e_notebooks $TMPDIR/e2e_notebooks
+    chmod -R +w $TMPDIR/e2e_notebooks
+    substituteInPlace tests/test_end_to_end.py --replace "tests/e2e_notebooks" "$TMPDIR/e2e_notebooks"
   '';
 
   meta = {