Add unit tests

.flake8

@@ -17,5 +17,5 @@ exclude =
 
     # Git
     .git/,
-application-import-names = torchgeo
+application-import-names = docs,tests,torchgeo
 import-order-style = google

.github/workflows/pytest.yaml

@@ -0,0 +1,35 @@
+name: pytest
+on:
+  push:
+    branches:
+    - main
+    paths:
+    - '**.py'
+    - 'requirements.txt'
+    - '.github/workflows/pytest.yaml'
+  pull_request:
+    branches:
+    - main
+    paths:
+    - '**.py'
+    - 'requirements.txt'
+    - '.github/workflows/pytest.yaml'
+jobs:
+  pytest:
+    name: pytest
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        python-version: [3.5, 3.6, 3.7, 3.8, 3.9]
+    steps:
+    - name: Clone repo
+      uses: actions/checkout@v2
+    - name: Set up python
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install dependencies
+      run: pip3 install -r requirements.txt
+    - name: Run pytest checks
+      run: pytest

requirements.txt

@@ -5,6 +5,8 @@ mypy
 opencv-python
 pillow
 pycocotools
+pytest
+pytest-cov
 pytorch-sphinx-theme
 radiant-mlhub>=0.2.1
 rarfile

setup.cfg

@@ -30,6 +30,9 @@ install_requires =
 python_requires = >= 3.5
 packages = find:
 
+[options.packages.find]
+include = torchgeo
+
 [options.extras_require]
 cv4akenyacroptype =
     radiant-mlhub>=0.2.1

spack.yaml

@@ -8,6 +8,8 @@ spack:
   - py-mypy
   - py-pillow-simd
   - py-pycocotools
+  - py-pytest
+  - py-pytest-cov
   - py-pytorch-sphinx-theme
   - "py-radiant-mlhub@0.2.1:"
   - py-rarfile

tests/datasets/test_utils.py

@@ -0,0 +1,22 @@
+import pathlib
+
+from torchgeo.datasets.utils import working_dir
+
+
+def test_existing_directory(tmp_path: pathlib.Path) -> None:
+    subdir = tmp_path / "foo" / "bar"
+    subdir.mkdir(parents=True)
+
+    assert subdir.exists()
+
+    with working_dir(str(subdir)):
+        assert subdir.cwd() == subdir
+
+
+def test_nonexisting_directory(tmp_path: pathlib.Path) -> None:
+    subdir = tmp_path / "foo" / "bar"
+
+    assert not subdir.exists()
+
+    with working_dir(str(subdir), create=True):
+        assert subdir.cwd() == subdir