1 files changed, 42 insertions, 0 deletions
diff --git a/pkgs/development/python-modules/invisible-watermark/tests/python/default.nix b/pkgs/development/python-modules/invisible-watermark/tests/python/default.nix
new file mode 100644
index 00000000000..63db5886737
--- /dev/null
+++ b/pkgs/development/python-modules/invisible-watermark/tests/python/default.nix
@@ -0,0 +1,42 @@
+{ image
+, invisible-watermark
+, opencv4
+, python3
+, runCommand
+, stdenvNoCC
+}:
+
+# This test checks if the python code shown in the README works correctly
+
+let
+  message = "fnörd1";
+  method = "dwtDct";
+
+  pythonWithPackages = python3.withPackages (pp: with pp; [ invisible-watermark opencv4 ]);
+  pythonInterpreter = pythonWithPackages.interpreter;
+
+  encode = stdenvNoCC.mkDerivation {
+    name = "encode";
+    realBuilder = pythonInterpreter;
+    args = [ ./encode.py ];
+    inherit image message method;
+  };
+
+  decode = stdenvNoCC.mkDerivation {
+    name = "decode";
+    realBuilder = pythonInterpreter;
+    args = [ ./decode.py ];
+    inherit method;
+    image = "${encode}/test_wm.png";
+    num_bits = (builtins.stringLength message) * 8;
+  };
+in
+runCommand "invisible-watermark-test-python" { } ''
+  decoded_message="$(cat '${decode}')"
+  if [ '${message}' != "$decoded_message" ]; then
+    echo "invisible-watermark did not decode the watermark correctly."
+    echo "The original message was ${message} but the decoded message was $decoded_message."
+    exit 1
+  fi
+  touch "$out"
+''