Merge pull request #24 from numpy/stringdtype-tests

Add tests for string dtype

Author: ngoldbaum

.github/workflows/ci.yml

@@ -64,3 +64,12 @@ jobs:
         working-directory: quaddtype
         run: |
           pytest -vvv --color=yes
+      - name: Install stringdtype
+        working-directory: stringdtype
+        run: |
+          python -m build --no-isolation --wheel -Cbuilddir=build
+          find ./dist/*.whl | xargs python -m pip install
+      - name: Run stringdtype tests
+        working-directory: stringdtype
+        run: |
+          pytest -vvv --color=yes

stringdtype/stringdtype/src/dtype.c

@@ -93,6 +93,10 @@ static int
 stringdtype_setitem(StringDTypeObject *descr, PyObject *obj, char **dataptr)
 {
     PyObject *val_obj = get_value(obj);
+    if (val_obj == NULL) {
+        return -1;
+    }
+
     char *val = NULL;
     Py_ssize_t length = 0;
     if (PyBytes_AsStringAndSize(val_obj, &val, &length) == -1) {

stringdtype/tests/test_stringdtype.py

@@ -0,0 +1,99 @@
+import numpy as np
+import pytest
+
+from stringdtype import StringDType, StringScalar
+
+
+@pytest.fixture
+def string_list():
+    return ['abc', 'def', 'ghi']
+
+
+def test_scalar_creation():
+    assert str(StringScalar('abc', StringDType())) == 'abc'
+
+
+def test_dtype_creation():
+    assert str(StringDType()) == 'StringDType'
+
+
+@pytest.mark.parametrize(
+    'data', [
+        ['abc', 'def', 'ghi'],
+        ["🤣", "📵", "😰"],
+        ["🚜", "🙃", "😾"],
+        ["😹", "🚠", "🚌"],
+    ]
+)
+def test_array_creation_utf8(data):
+    arr = np.array(data, dtype=StringDType())
+    assert repr(arr) == f'array({str(data)}, dtype=StringDType)'
+
+
+def test_array_creation_scalars(string_list):
+    dtype = StringDType()
+    arr = np.array(
+        [
+            StringScalar('abc', dtype=dtype),
+            StringScalar('def', dtype=dtype),
+            StringScalar('ghi', dtype=dtype),
+        ]
+    )
+    assert repr(arr) == repr(np.array(string_list, dtype=StringDType()))
+
+
+@pytest.mark.parametrize(
+   'data', [
+       [1, 2, 3],
+       [None, None, None],
+       [b'abc', b'def', b'ghi'],
+       [object, object, object],
+   ]
+)
+def test_bad_scalars(data):
+    with pytest.raises(TypeError):
+        np.array(data, dtype=StringDType())
+
+
+@pytest.mark.xfail(reason='Not yet implemented')
+def test_cast_to_stringdtype(string_list):
+    arr = np.array(string_list, dtype='<U3').astype(StringDType())
+    expected = np.array(string_list, dtype=StringDType())
+    np.testing.assert_array_equal(arr, expected)
+
+
+@pytest.mark.xfail(reason='Not yet implemented')
+def test_cast_to_unicode_safe(string_list):
+    arr = np.array(string_list, dtype=StringDType())
+
+    np.testing.assert_array_equal(
+        arr.astype('<U3', casting='safe'),
+        np.array(string_list, dtype='<U3')
+    )
+
+    # Safe casting should preserve data
+    with pytest.raises(TypeError):
+        arr.astype('<U2', casting='safe')
+
+
+@pytest.mark.xfail(reason='Not yet implemented')
+def test_cast_to_unicode_unsafe(string_list):
+    arr = np.array(string_list, dtype=StringDType())
+
+    np.testing.assert_array_equal(
+        arr.astype('<U3', casting='unsafe'),
+        np.array(string_list, dtype='<U3')
+    )
+
+    # Unsafe casting: each element is truncated
+    np.testing.assert_array_equal(
+        arr.astype('<U2', casting='unsafe'),
+        np.array(string_list, dtype='<U2')
+    )
+
+
+def test_insert_scalar(string_list):
+    dtype = StringDType()
+    arr = np.array(string_list, dtype=dtype)
+    arr[1] = StringScalar('what', dtype=dtype)
+    assert repr(arr) == repr(np.array(['abc', 'what', 'ghi'], dtype=dtype))