Add some unit tests

.github/workflows/CI.yml

@@ -87,6 +87,33 @@ jobs:
           name: wheels-${{ runner.os }}-${{ matrix.target }}
           path: dist/*
 
+  test:
+    name: Test wheels on ${{ matrix.os }} (${{ matrix.python-version }})
+    needs: linux
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest]
+        python-version: ['3.10']
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Download x86_64 wheels
+        uses: actions/download-artifact@v4
+        with:
+          name: wheels-Linux-x86_64
+          path: dist
+      - name: Install wheel and dependencies
+        run: |
+          pip install --upgrade pip
+          pip install --no-index --find-links=dist lightningcss
+          pip install --group dev
+      - name: Run tests
+        run: pytest
+
   sdist:
     runs-on: ubuntu-latest
     steps:

pyproject.toml

@@ -37,6 +37,10 @@ classifiers = [
 [project.urls]
 Source = "https://github.com/pydsigner/python-lightningcss"
 
+[dependency-groups]
+dev = [
+    "pytest>=9.0.2",
+]
 
 [tool.maturin]
 features = ["pyo3/extension-module"]

tests/data/invalid.css

@@ -0,0 +1,5 @@
+* {
+  box-sizing: border-box;
+}
+
+something invalid

tests/data/main.css

@@ -0,0 +1,5 @@
+@import "normalize.css" layer(normalize);
+
+a {
+  color: blue;
+}

tests/data/normalize.css

@@ -0,0 +1,3 @@
+* {
+  box-sizing: border-box;
+}

tests/test_bundle_css.py

@@ -0,0 +1,30 @@
+from pathlib import Path
+import pytest
+import lightningcss as lcss
+
+TEST_DATA_DIR = Path(__file__).parent / "data"
+MAIN_CSS_PATH = TEST_DATA_DIR / "main.css"
+NORMALIZE_CSS_PATH = TEST_DATA_DIR / "normalize.css"
+MISSING_CSS_PATH = TEST_DATA_DIR / "not-there.css"
+INVALID_CSS_PATH = TEST_DATA_DIR / "invalid.css"
+
+
+def test_minify():
+    expected = "@layer normalize{*{box-sizing:border-box}}a{color:#00f}"
+
+    result = lcss.bundle_css(str(MAIN_CSS_PATH))
+    assert result == expected
+
+def test_pretty_print():
+    expected = "* {\n  box-sizing: border-box;\n}\n"
+
+    result = lcss.bundle_css(str(NORMALIZE_CSS_PATH), minify=False)
+    assert result == expected
+
+def test_file_not_found():
+    with pytest.raises(OSError):
+        lcss.bundle_css(str(MISSING_CSS_PATH))
+
+def test_parse_error():
+    with pytest.raises(ValueError):
+        lcss.bundle_css(str(INVALID_CSS_PATH))

tests/test_process_stylesheet.py

@@ -0,0 +1,33 @@
+import lightningcss as lcss
+import pytest
+
+
+def test_minify():
+    code = ".content { margin-inline: 3vw; padding: 1rem 2rem 1rem 2rem; }"
+    expected = ".content{margin-inline:3vw;padding:1rem 2rem}"
+
+    result = lcss.process_stylesheet(code)
+    assert result == expected
+
+def test_pretty_print():
+    code = ".content { margin: 3vw; }"
+    expected = ".content {\n  margin: 3vw;\n}\n"
+
+    result = lcss.process_stylesheet(code, minify=False)
+    assert result == expected
+
+def test_parse_error():
+    code = "img { display: block; } nonsense }{ non-terminated"
+
+    with pytest.raises(ValueError):
+        lcss.process_stylesheet(code)
+
+def test_error_recovery():
+    code = "img { display: block; } nonsense }{ non-terminated"
+    expected = "img{display:block}"
+
+    with pytest.raises(ValueError):
+        lcss.process_stylesheet(code, error_recovery=False)
+
+    result = lcss.process_stylesheet(code, error_recovery=True)
+    assert result == expected