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[EDIT] FILE: test_build_clib.py

import random
from unittest import mock

import pytest

from setuptools.command.build_clib import build_clib
from setuptools.dist import Distribution

from distutils.errors import DistutilsSetupError

class TestBuildCLib:
    @mock.patch('setuptools.command.build_clib.newer_pairwise_group')
    def test_build_libraries(self, mock_newer):
        dist = Distribution()
        cmd = build_clib(dist)

# this will be a long section, just making sure all
        # exceptions are properly raised
        libs = [('example', {'sources': 'broken.c'})]
        with pytest.raises(DistutilsSetupError):
            cmd.build_libraries(libs)

obj_deps = 'some_string'
        libs = [('example', {'sources': ['source.c'], 'obj_deps': obj_deps})]
        with pytest.raises(DistutilsSetupError):
            cmd.build_libraries(libs)

obj_deps = {'': ''}
        libs = [('example', {'sources': ['source.c'], 'obj_deps': obj_deps})]
        with pytest.raises(DistutilsSetupError):
            cmd.build_libraries(libs)

obj_deps = {'source.c': ''}
        libs = [('example', {'sources': ['source.c'], 'obj_deps': obj_deps})]
        with pytest.raises(DistutilsSetupError):
            cmd.build_libraries(libs)

# with that out of the way, let's see if the crude dependency
        # system works
        cmd.compiler = mock.MagicMock(spec=cmd.compiler)
        mock_newer.return_value = ([], [])

obj_deps = {'': ('global.h',), 'example.c': ('example.h',)}
        libs = [('example', {'sources': ['example.c'], 'obj_deps': obj_deps})]

cmd.build_libraries(libs)
        assert [['example.c', 'global.h', 'example.h']] in mock_newer.call_args[0]
        assert not cmd.compiler.compile.called
        assert cmd.compiler.create_static_lib.call_count == 1

# reset the call numbers so we can test again
        cmd.compiler.reset_mock()

mock_newer.return_value = ''  # anything as long as it's not ([],[])
        cmd.build_libraries(libs)
        assert cmd.compiler.compile.call_count == 1
        assert cmd.compiler.create_static_lib.call_count == 1

@mock.patch('setuptools.command.build_clib.newer_pairwise_group')
    def test_build_libraries_reproducible(self, mock_newer):
        dist = Distribution()
        cmd = build_clib(dist)

# with that out of the way, let's see if the crude dependency
        # system works
        cmd.compiler = mock.MagicMock(spec=cmd.compiler)
        mock_newer.return_value = ([], [])

original_sources = ['a-example.c', 'example.c']
        sources = original_sources

obj_deps = {'': ('global.h',), 'example.c': ('example.h',)}
        libs = [('example', {'sources': sources, 'obj_deps': obj_deps})]

cmd.build_libraries(libs)
        computed_call_args = mock_newer.call_args[0]

while sources == original_sources:
            sources = random.sample(original_sources, len(original_sources))
        libs = [('example', {'sources': sources, 'obj_deps': obj_deps})]

cmd.build_libraries(libs)
        assert computed_call_args == mock_newer.call_args[0]

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