CI: add a build against numpy nightly

Author: jakevdp

.github/workflows/test.yml

@@ -23,17 +23,23 @@ jobs:
           python-version: 3.9
       - uses: pre-commit/action@v3.0.0
   build:
-    name: ${{ matrix.os }} Python ${{ matrix.python-version }}
+    name: ${{ matrix.os }} Python ${{ matrix.python-version }} numpy-nightly=${{ matrix.numpy-nightly }}
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
         os: ["ubuntu-latest"]
         python-version: ["3.9", "3.10", "3.11", "3.12"]
+        numpy-nightly: [false]
         include:
+          - os: ubuntu-latest
+            python-version: "3.12"
+            numpy-nightly: true
           - os: macOS-11
             python-version: "3.11"
+            numpy-nightly: false
           - os: windows-2019
             python-version: "3.11"
+            numpy-nightly: false
 
     steps:
       - uses: actions/checkout@v3
@@ -47,6 +53,12 @@ jobs:
         run: |
           python -m pip install --upgrade pip
           pip install .[dev]
+      - name: Install numpy nightly
+        if: ${{ matrix.numpy-nightly == true }}
+        run: |
+            pip install -U --pre numpy \
+              -i https://pypi.anaconda.org/scientific-python-nightly-wheels/simple
+
       - name: Run tests
         run: |
           pytest -n auto

ml_dtypes/tests/custom_float_test.py

@@ -703,7 +703,7 @@ def testCasts(self, float_type):
       self.assertTrue(np.all(x == z))
       self.assertEqual(dtype, z.dtype)
 
-  @ignore_warning(category=np.ComplexWarning)
+  @ignore_warning(category=np.exceptions.ComplexWarning)
   def testConformNumpyComplex(self, float_type):
     for dtype in [np.complex64, np.complex128, np.clongdouble]:
       x = np.array([1.5, 2.5 + 2.0j, 3.5], dtype=dtype)

pytest.ini

@@ -1,3 +1,4 @@
 [pytest]
 filterwarnings =
     error
+    ignore:numpy.core._multiarray_umat.*:DeprecationWarning