tests/test_collector.py

# Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0
# For details: https://github.com/nedbat/coveragepy/blob/master/NOTICE.txt

"""Tests of coverage/collector.py and other collectors."""

import os.path

import coverage

from tests.coveragetest import CoverageTest
from tests.helpers import CheckUniqueFilenames


class CollectorTest(CoverageTest):
    """Test specific aspects of the collection process."""

    def test_should_trace_cache(self):
        # The tracers should only invoke should_trace once for each file name.

        # Make some files that invoke each other.
        self.make_file("f1.py", """\
            def f1(x, f):
                return f(x)
            """)

        self.make_file("f2.py", """\
            import f1

            def func(x):
                return f1.f1(x, otherfunc)

            def otherfunc(x):
                return x*x

            for i in range(10):
                func(i)
            """)

        # Trace one file, but not the other. CheckUniqueFilenames will assert
        # that _should_trace hasn't been called twice for the same file.
        cov = coverage.Coverage(include=["f1.py"])
        should_trace_hook = CheckUniqueFilenames.hook(cov, '_should_trace')

        # Import the Python file, executing it.
        self.start_import_stop(cov, "f2")

        # Double-check that our files were checked.
        abs_files = set(os.path.abspath(f) for f in should_trace_hook.filenames)
        self.assertIn(os.path.abspath("f1.py"), abs_files)
        self.assertIn(os.path.abspath("f2.py"), abs_files)