Specify error message on non-contiguous numpy array

Author: ijl

src/serialize/serializer.rs

@@ -330,14 +330,18 @@ impl<'p> Serialize for PyObjectSerializer {
                 Ok(val) => val.serialize(serializer),
                 Err(PyArrayError::Malformed) => err!("numpy array is malformed"),
                 Err(PyArrayError::NotContiguous) | Err(PyArrayError::UnsupportedDataType) => {
-                    DefaultSerializer::new(
-                        self.ptr,
-                        self.opts,
-                        self.default_calls,
-                        self.recursion,
-                        self.default,
-                    )
-                    .serialize(serializer)
+                    if self.default.is_none() {
+                        err!("numpy array is not C contiguous; use ndarray.tolist() in default")
+                    } else {
+                        DefaultSerializer::new(
+                            self.ptr,
+                            self.opts,
+                            self.default_calls,
+                            self.recursion,
+                            self.default,
+                        )
+                        .serialize(serializer)
+                    }
                 }
             },
             ObType::NumpyScalar => NumpyScalar::new(self.ptr).serialize(serializer),

test/test_numpy.py

@@ -182,7 +182,7 @@ def test_numpy_array_d3_f64(self):
             b"[[[1.0,2.0],[3.0,4.0]],[[5.0,6.0],[7.0,8.0]]]",
         )
 
-    def test_numpy_array_fotran(self):
+    def test_numpy_array_fortran(self):
         array = numpy.array([[1, 2], [3, 4]], order="F")
         assert array.flags["F_CONTIGUOUS"] == True
         with self.assertRaises(orjson.JSONEncodeError):
@@ -194,6 +194,18 @@ def test_numpy_array_fotran(self):
             orjson.dumps(array.tolist()),
         )
 
+    def test_numpy_array_non_contiguous_message(self):
+        array = numpy.array([[1, 2], [3, 4]], order="F")
+        assert array.flags["F_CONTIGUOUS"] == True
+        try:
+            orjson.dumps(array, option=orjson.OPT_SERIALIZE_NUMPY)
+            assert False
+        except TypeError as exc:
+            self.assertEqual(
+                str(exc),
+                "numpy array is not C contiguous; use ndarray.tolist() in default",
+            )
+
     def test_numpy_array_unsupported_dtype(self):
         array = numpy.array([[1, 2], [3, 4]], numpy.float16)
         with self.assertRaises(orjson.JSONEncodeError):