chore: validate httpx package is not installed by default

.github/workflows/test.yml

@@ -102,3 +102,39 @@ jobs:
           files: ./coverage.xml
           flags: unit
           fail_ci_if_error: false
+
+  dist:
+    runs-on: ubuntu-latest
+    name: Python wheel
+    steps:
+    - uses: actions/checkout@v1
+    - uses: actions/setup-python@v2
+      with:
+        python-version: "3.11"
+    - name: Install dependencies
+      run: |
+        pip install -r requirements-test.txt
+    - name: Build package
+      run: python -m build -o dist/
+    - uses: actions/upload-artifact@v2
+      with:
+        name: dist
+        path: dist
+
+  test:
+    runs-on: ubuntu-latest
+    needs: [dist]
+    steps:
+    - uses: actions/checkout@v3
+    - name: Set up Python
+      uses: actions/setup-python@v4
+      with:
+        python-version: '3.11'
+    - uses: actions/download-artifact@v2
+      with:
+        name: dist
+        path: dist
+    - name: install dist/*.whl and requirements
+      run: pip install dist/*.whl -r requirements-test.txt tox
+    - name: Run tests
+      run: tox -e install

requirements-test.txt

+build==0.9.0
 coverage==6.5.0
-pytest==7.1.3
 pytest-console-scripts==1.3.1
 pytest-cov==4.0.0
 pytest-github-actions-annotate-failures==0.1.7
+pytest==7.1.3
 PyYaml==5.4.1
 responses==0.21.0

tests/install/test_install.py

+import pytest
+
+
+def test_install() -> None:
+    with pytest.raises(ImportError):
+        import httpx  # type: ignore # noqa

tox.ini

@@ -128,3 +128,9 @@ commands = pytest tests/smoke {posargs}
 skip_install = true
 deps = -r requirements-precommit.txt
 commands = pre-commit run --all-files --show-diff-on-failure
+
+[testenv:install]
+skip_install = true
+deps = -r{toxinidir}/requirements.txt
+       -r{toxinidir}/requirements-test.txt
+commands = pytest tests/install