[Tensor] Add unit tests for scalar tensor

Add test_tensor_scalar.py python unit tests testing:
- construction with 0-rank np array,
- contruction with scalar numpy types
- access/coord/idx on scalar tensor.

aidge_core/unit_tests/test_tensor_scalar.py

+"""
+Copyright (c) 2023 CEA-List
+
+This program and the accompanying materials are made available under the
+terms of the Eclipse Public License 2.0 which is available at
+http://www.eclipse.org/legal/epl-2.0.
+
+SPDX-License-Identifier: EPL-2.0
+"""
+
+import unittest
+import numpy as np
+
+import aidge_core
+
+class test_tensor_scalar(unittest.TestCase):
+    """Test tensor binding for scalar (0-rank) tensors
+    """
+    def setUp(self):
+        pass
+    def tearDown(self):
+        pass
+
+    def _scalar_np_array(self, dtype=None):
+        return np.array(1, dtype=dtype)
+
+    def _scalar_np(self, dtype=None):
+        return np.int32(1).astype(dtype)
+    
+    def test_np_array_int_to_tensor(self):
+        np_array = self._scalar_np_array(dtype="int8")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.int8)
+
+        np_array = self._scalar_np_array(dtype="int16")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.int16)
+
+        np_array = self._scalar_np_array(dtype="int32")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.int32)
+
+        np_array = self._scalar_np_array(dtype="int64")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.int64)
+
+    def test_np_array_uint_to_tensor(self):
+        np_array = self._scalar_np_array(dtype="uint8")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.uint8)
+
+        np_array = self._scalar_np_array(dtype="uint16")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.uint16)
+
+        np_array = self._scalar_np_array(dtype="uint32")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.uint32)
+
+        np_array = self._scalar_np_array(dtype="uint64")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.uint64)
+        
+    def test_np_scalar_int_to_tensor(self):
+        np_array = self._scalar_np(dtype="int8")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.int8)
+
+        np_array = self._scalar_np(dtype="int16")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.int16)
+
+        np_array = self._scalar_np(dtype="int32")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.int32)
+
+        np_array = self._scalar_np(dtype="int64")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.int64)
+
+    def test_np_scalar_uint_to_tensor(self):
+        np_array = self._scalar_np(dtype="uint8")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.uint8)
+
+        np_array = self._scalar_np(dtype="uint16")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.uint16)
+
+        np_array = self._scalar_np(dtype="uint32")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.uint32)
+
+        np_array = self._scalar_np(dtype="uint64")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.uint64)
+        
+    def test_np_array_float_to_tensor(self):
+        np_array = self._scalar_np_array(dtype="float32")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.float32)
+        np_array = self._scalar_np_array(dtype="float64")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.float64)
+
+    def test_np_scalar_float_to_tensor(self):
+        np_array = self._scalar_np(dtype="float32")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.float32)
+        np_array = self._scalar_np(dtype="float64")
+        t = aidge_core.Tensor(np_array)
+        self.assertEqual(t.dtype(), aidge_core.dtype.float64)
+
+    def test_getcoord_getidx_scalar(self):
+        np_array = self._scalar_np_array()
+        t = aidge_core.Tensor(np_array)
+        coord = t.get_coord(0)
+        self.assertEqual(tuple(coord), ())
+        idx = t.get_idx(coord)
+        self.assertEqual(idx, 0)
+
+    def test_indexing_scalar(self):
+        np_array = self._scalar_np_array()
+        t = aidge_core.Tensor(np_array)
+        val = t[0]
+        self.assertEqual(val, np_array[()])
+
+    def test_coord_indexing_scalar(self):
+        np_array = self._scalar_np_array()
+        t = aidge_core.Tensor(np_array)
+        val = t[()]
+        self.assertEqual(val, np_array[()])
+
+
+if __name__ == '__main__':
+    unittest.main()