Fix build and test system

* test only on recent versions of python
* test for compatibility with numpy v1
* force minimum version compatibility for numpy v1

.github/workflows/test.yml

@@ -10,18 +10,14 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        python-version: ['3.7', '3.8', '3.9', '3.10', '3.11', '3.12']
-        # exclude MacOS arm64 on 3.7
-        exclude:
-          - os: macos-latest
-            python-version: '3.7'
+        python-version: ['3.9', '3.10', '3.11', '3.12']
     runs-on: ${{ matrix.os }}
     steps:
     - name: Check out code
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Set up Python
-      uses: actions/setup-python@v3
+      uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
 
@@ -33,7 +29,41 @@ jobs:
         pip install -e .
 
     - name: Run linting tests on files in src
-      run: ruff src
+      run: ruff check src
 
     - name: Run tests
-      run: pytest
+      run: pytest
+
+  # test old versions of numpy; this follows advice in
+  # https://numpy.org/doc/stable/dev/depending_on_numpy.html#depending-on-numpy
+  old_numpy_test:
+    strategy:
+      matrix:
+        os: [ubuntu-latest]
+        python-version: ['3.9', '3.10', '3.11', '3.12']
+    runs-on: ${{ matrix.os }}
+    steps:
+    - name: Check out code
+      uses: actions/checkout@v4
+
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: ${{ matrix.python-version }}
+
+    - name: Build wheel via wheel, then install it
+      run: |
+        python -m pip install build
+        python -m build  # This will pull in numpy 2.0 in an isolated env
+        python -m pip install dist/*.whl
+
+    - name: Test against oldest supported numpy version
+      run: |
+        python -m pip install --upgrade pip
+        python -m pip install --upgrade setuptools
+        python -m pip install numpy==1.26.4
+        # now run test suite
+        pip install -r requirements.txt
+        pip install pytest ruff
+        pip install -e .
+        pytest

pyproject.toml

@@ -1,6 +1,11 @@
 [project]
 name = "fastkde"
-dynamic = ["dependencies", "version", "optional-dependencies", "description", "readme", "authors", "keywords"]
+dynamic = ["version", "optional-dependencies", "description", "readme", "authors", "keywords"]
+dependencies = [
+    "numpy>=1.26.4",
+    "scipy",
+    "xarray",
+]
 
 [tool.setuptools.dynamic]
 dependencies = {file = ["requirements.txt"]}
@@ -16,7 +21,7 @@ requires = [
     "wheel",
     "toml",
     "setuptools_scm>=4.1.2",
-    "oldest-supported-numpy; python_version>='3.5'",
+    "numpy>=2.0.0",
 ]
 
 build-backend = "setuptools.build_meta"