testing-patterns

Testing Patterns

Test Structure

File Naming

• Test files: test_*.py in tests/ directory
• One test file per format/feature: test_csv.py, test_parquet.py
• Test classes: Test* (e.g., TestCSV, TestParquet)
• Test functions: test_* (e.g., test_read, test_write)

Running Tests

# All tests
pytest --verbose

# Specific test file
pytest tests/test_csv.py -v

# Specific test function
pytest tests/test_csv.py::TestCSV::test_read -v

# Parallel execution
pytest -n auto

# With coverage
pytest --cov=iterable --cov-report=html

Test Patterns

Basic Read Test

def test_read(self):
    with open_iterable('testdata/test.csv') as source:
        rows = list(source)
        assert len(rows) > 0
        assert isinstance(rows[0], dict)

Basic Write Test

def test_write(self, tmp_path):
    output = tmp_path / 'output.csv'
    data = [{'col1': 'val1', 'col2': 'val2'}]
    
    with open_iterable(output, 'w') as dest:
        dest.write_bulk(data)
    
    # Verify written data
    with open_iterable(output) as source:
        rows = list(source)
        assert rows == data

Compression Tests

def test_gzip_compression(self):
    with open_iterable('testdata/test.csv.gz') as source:
        rows = list(source)
        assert len(rows) > 0

Bulk Operations Test

def test_read_bulk(self):
    with open_iterable('testdata/test.csv') as source:
        chunks = list(source.read_bulk(size=100))
        assert len(chunks) > 0
        assert all(isinstance(chunk, list) for chunk in chunks)

Edge Cases

def test_empty_file(self):
    with open_iterable('testdata/empty.csv') as source:
        rows = list(source)
        assert rows == []

def test_malformed_data(self):
    with pytest.raises(ValueError):
        with open_iterable('testdata/malformed.csv') as source:
            list(source)