| Message ID | 20201130233242.78413-1-dlatypov@google.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [1/5] kunit: tool: fix unit test cleanup handling | expand |
On Tue, Dec 1, 2020 at 7:32 AM Daniel Latypov <dlatypov@google.com> wrote: > > * Stop leaking file objects. > * Use self.addCleanup() to ensure we call cleanup functions even if > setUp() fails. > * use mock.patch.stopall instead of more error-prone manual approach > > Signed-off-by: Daniel Latypov <dlatypov@google.com> > --- I won't pretend to be an expert on Python, but this seems good to me. I tested it on my machine and it works fine. So, Reviewed-by: David Gow <davidgow@google.com> -- Davkd > tools/testing/kunit/kunit_tool_test.py | 14 ++++++-------- > 1 file changed, 6 insertions(+), 8 deletions(-) > > diff --git a/tools/testing/kunit/kunit_tool_test.py b/tools/testing/kunit/kunit_tool_test.py > index 497ab51bc170..3fbe1acd531a 100755 > --- a/tools/testing/kunit/kunit_tool_test.py > +++ b/tools/testing/kunit/kunit_tool_test.py > @@ -288,19 +288,17 @@ class StrContains(str): > class KUnitMainTest(unittest.TestCase): > def setUp(self): > path = get_absolute_path('test_data/test_is_test_passed-all_passed.log') > - file = open(path) > - all_passed_log = file.readlines() > - self.print_patch = mock.patch('builtins.print') > - self.print_mock = self.print_patch.start() > + with open(path) as file: > + all_passed_log = file.readlines() > + > + self.print_mock = mock.patch('builtins.print').start() > + self.addCleanup(mock.patch.stopall) > + > self.linux_source_mock = mock.Mock() > self.linux_source_mock.build_reconfig = mock.Mock(return_value=True) > self.linux_source_mock.build_um_kernel = mock.Mock(return_value=True) > self.linux_source_mock.run_kernel = mock.Mock(return_value=all_passed_log) > > - def tearDown(self): > - self.print_patch.stop() > - pass > - > def test_config_passes_args_pass(self): > kunit.main(['config', '--build_dir=.kunit'], self.linux_source_mock) > assert self.linux_source_mock.build_reconfig.call_count == 1 > > base-commit: b65054597872ce3aefbc6a666385eabdf9e288da > -- > 2.29.2.454.gaff20da3a2-goog >
On Tue, Dec 1, 2020 at 7:33 AM Daniel Latypov <dlatypov@google.com> wrote: > > get_absolute_path() makes an attempt to allow for this. > But that doesn't work as soon as os.chdir() gets called. Can we explain why this doesn't work? It's because the test_data/ files are accessed with relative paths, so chdir breaks access to them, right? > > So make it so that os.chdir() does nothing to avoid this. > > Note: mock.patch.object() doesn't seem to work in setUpModule(), hence > the introduction of a new base class instead. > > Fixes: 5578d008d9e0 ("kunit: tool: fix running kunit_tool from outside kernel tree") > Signed-off-by: Daniel Latypov <dlatypov@google.com> > --- I don't like this: disabling a real system call seems like overkill to work around a path issue like this. Wouldn't it be better to either: (a) stop kunit_tool from needing to chdir entirely; or (b) have get_absolute_path() / test_data_path() produce an absolute path. The latter really seems like the most sensible approach: have the script read its own path and read files relative to that. Cheers, -- David > tools/testing/kunit/kunit_tool_test.py | 15 +++++++++++---- > 1 file changed, 11 insertions(+), 4 deletions(-) > > diff --git a/tools/testing/kunit/kunit_tool_test.py b/tools/testing/kunit/kunit_tool_test.py > index 3fbe1acd531a..9f1f1e1b772a 100755 > --- a/tools/testing/kunit/kunit_tool_test.py > +++ b/tools/testing/kunit/kunit_tool_test.py > @@ -32,7 +32,13 @@ def tearDownModule(): > def get_absolute_path(path): > return os.path.join(os.path.dirname(__file__), path) > > -class KconfigTest(unittest.TestCase): > +class KUnitTest(unittest.TestCase): > + """Contains common setup, like stopping main() from calling chdir.""" > + def setUp(self): > + mock.patch.object(os, 'chdir').start() > + self.addCleanup(mock.patch.stopall) > + > +class KconfigTest(KUnitTest): > > def test_is_subset_of(self): > kconfig0 = kunit_config.Kconfig() > @@ -88,7 +94,7 @@ class KconfigTest(unittest.TestCase): > self.assertEqual(actual_kconfig.entries(), > expected_kconfig.entries()) > > -class KUnitParserTest(unittest.TestCase): > +class KUnitParserTest(KUnitTest): > > def assertContains(self, needle, haystack): > for line in haystack: > @@ -250,7 +256,7 @@ class KUnitParserTest(unittest.TestCase): > result.status) > self.assertEqual('kunit-resource-test', result.suites[0].name) > > -class KUnitJsonTest(unittest.TestCase): > +class KUnitJsonTest(KUnitTest): > > def _json_for(self, log_file): > with(open(get_absolute_path(log_file))) as file: > @@ -285,8 +291,9 @@ class StrContains(str): > def __eq__(self, other): > return self in other > > -class KUnitMainTest(unittest.TestCase): > +class KUnitMainTest(KUnitTest): > def setUp(self): > + super().setUp() > path = get_absolute_path('test_data/test_is_test_passed-all_passed.log') > with open(path) as file: > all_passed_log = file.readlines() > -- > 2.29.2.454.gaff20da3a2-goog >
On Tue, Dec 1, 2020 at 7:33 AM Daniel Latypov <dlatypov@google.com> wrote: > > The use of manual open() and .close() calls seems to be an attempt to > keep the contents in scope. > But Python doesn't restrict variables like that, so we can introduce new > variables inside of a `with` and use them outside. > > Do so to make the code more Pythonic. > > Signed-off-by: Daniel Latypov <dlatypov@google.com> > --- I'm fine with this, and it clearly works fine for me. Out of curiosity, though, is there any difference here other than it being more usual Python style? We've struggled a bit in the past toeing a line between trying to follow "normal" Python style versus adapting it a bit to be more "kernel-y". Experience thus far has actually been that going out on our own has caused more problems than it solves, so I'm all for this change, but I do admit that my brain does understand the older code a touch more easily. In any case, Reviewed-by: David Gow <davidgow@google.com> -- David
On Mon, Nov 30, 2020 at 11:33 PM David Gow <davidgow@google.com> wrote: > > On Tue, Dec 1, 2020 at 7:33 AM Daniel Latypov <dlatypov@google.com> wrote: > > > > The use of manual open() and .close() calls seems to be an attempt to > > keep the contents in scope. > > But Python doesn't restrict variables like that, so we can introduce new > > variables inside of a `with` and use them outside. > > > > Do so to make the code more Pythonic. > > > > Signed-off-by: Daniel Latypov <dlatypov@google.com> > > --- > I'm fine with this, and it clearly works fine for me. Out of > curiosity, though, is there any difference here other than it being > more usual Python style? Files aren't leaked if we error out due to some exception before we call close(). And self.assertEqual() and friends raise exceptions on failure, so we're toeing that line here. But other than being more robust, it should be equivalent. > > We've struggled a bit in the past toeing a line between trying to > follow "normal" Python style versus adapting it a bit to be more > "kernel-y". Experience thus far has actually been that going out on > our own has caused more problems than it solves, so I'm all for this > change, but I do admit that my brain does understand the older code a > touch more easily. Ack. Python's lack of lexical scopes is a bit disconcerting. But from a readability standpoint, it's a bit more self-evident than having to write it would be, imo. So I think following more standard Python style here outweighs the cost. > > In any case, > Reviewed-by: David Gow <davidgow@google.com> > > > -- David
On Mon, Nov 30, 2020 at 11:33 PM David Gow <davidgow@google.com> wrote: > > On Tue, Dec 1, 2020 at 7:33 AM Daniel Latypov <dlatypov@google.com> wrote: > > > > get_absolute_path() makes an attempt to allow for this. > > But that doesn't work as soon as os.chdir() gets called. > > Can we explain why this doesn't work? It's because the test_data/ > files are accessed with relative paths, so chdir breaks access to > them, right? Correct. Because it actually returns a relative path. (I forgot that I called out that get_absolute_path() gives relative paths in the last patch, and not this one. I can update the commit desc if we want a v2 of this) > > > > > So make it so that os.chdir() does nothing to avoid this. > > > > Note: mock.patch.object() doesn't seem to work in setUpModule(), hence > > the introduction of a new base class instead. > > > > Fixes: 5578d008d9e0 ("kunit: tool: fix running kunit_tool from outside kernel tree") > > Signed-off-by: Daniel Latypov <dlatypov@google.com> > > --- > > I don't like this: disabling a real system call seems like overkill to > work around a path issue like this. > > Wouldn't it be better to either: > (a) stop kunit_tool from needing to chdir entirely; or a) is doable, but would require plumbing cwd=get_kernel_root_path() to all the subprocess calls to make, etc. I'm not sure fixing a internal test-only issue necessarily justifies taking that path instead of the easier "just add a chdir" we opted for in 5578d008d9e0 ("kunit: tool: fix running kunit_tool from outside kernel tree"). > (b) have get_absolute_path() / test_data_path() produce an absolute path. > > The latter really seems like the most sensible approach: have the > script read its own path and read files relative to that. b) is not that simple, sadly. Say I invoke $ python3 kunit_tool_test.py then __file__ = kunit_tool_test.py. So __file__ is a relative path, but the code assumed it was an absolute one and any change of directory breaks things. Working around that would require something like caching the result of os.path.abspath(__file__) somewhere. I can see the point about not mocking out something like os.chdir(). But on the other hand, do we have any other legitimate reason to call it besides that one place in kunit.py? If we do have something that relies on doing an os.chdir(), it should ideally notice that it didn't work and manifest in a unit test failure somehow. Alternatively, we could make get_kernel_root_path() return ""/None to avoid the chdir call. kunit.py: if get_kernel_root_path(): kunit.py: os.chdir(get_kernel_root_path()) There'd be no adverse affects atm for stubbing that out, and I don't forsee any. But if we want to be even safer, then perhaps we have def chdir_to_kernel_root(): ... and mock out just that func in the unit test? > > Cheers, > -- David > > > > tools/testing/kunit/kunit_tool_test.py | 15 +++++++++++---- > > 1 file changed, 11 insertions(+), 4 deletions(-) > > > > diff --git a/tools/testing/kunit/kunit_tool_test.py b/tools/testing/kunit/kunit_tool_test.py > > index 3fbe1acd531a..9f1f1e1b772a 100755 > > --- a/tools/testing/kunit/kunit_tool_test.py > > +++ b/tools/testing/kunit/kunit_tool_test.py > > @@ -32,7 +32,13 @@ def tearDownModule(): > > def get_absolute_path(path): > > return os.path.join(os.path.dirname(__file__), path) > > > > -class KconfigTest(unittest.TestCase): > > +class KUnitTest(unittest.TestCase): > > + """Contains common setup, like stopping main() from calling chdir.""" > > + def setUp(self): > > + mock.patch.object(os, 'chdir').start() > > + self.addCleanup(mock.patch.stopall) > > + > > +class KconfigTest(KUnitTest): > > > > def test_is_subset_of(self): > > kconfig0 = kunit_config.Kconfig() > > @@ -88,7 +94,7 @@ class KconfigTest(unittest.TestCase): > > self.assertEqual(actual_kconfig.entries(), > > expected_kconfig.entries()) > > > > -class KUnitParserTest(unittest.TestCase): > > +class KUnitParserTest(KUnitTest): > > > > def assertContains(self, needle, haystack): > > for line in haystack: > > @@ -250,7 +256,7 @@ class KUnitParserTest(unittest.TestCase): > > result.status) > > self.assertEqual('kunit-resource-test', result.suites[0].name) > > > > -class KUnitJsonTest(unittest.TestCase): > > +class KUnitJsonTest(KUnitTest): > > > > def _json_for(self, log_file): > > with(open(get_absolute_path(log_file))) as file: > > @@ -285,8 +291,9 @@ class StrContains(str): > > def __eq__(self, other): > > return self in other > > > > -class KUnitMainTest(unittest.TestCase): > > +class KUnitMainTest(KUnitTest): > > def setUp(self): > > + super().setUp() > > path = get_absolute_path('test_data/test_is_test_passed-all_passed.log') > > with open(path) as file: > > all_passed_log = file.readlines() > > -- > > 2.29.2.454.gaff20da3a2-goog > >
On Wed, Dec 2, 2020 at 3:00 AM Daniel Latypov <dlatypov@google.com> wrote: > > On Mon, Nov 30, 2020 at 11:33 PM David Gow <davidgow@google.com> wrote: > > > > On Tue, Dec 1, 2020 at 7:33 AM Daniel Latypov <dlatypov@google.com> wrote: > > > > > > get_absolute_path() makes an attempt to allow for this. > > > But that doesn't work as soon as os.chdir() gets called. > > > > Can we explain why this doesn't work? It's because the test_data/ > > files are accessed with relative paths, so chdir breaks access to > > them, right? > > Correct. > Because it actually returns a relative path. > > (I forgot that I called out that get_absolute_path() gives relative > paths in the last patch, and not this one. I can update the commit > desc if we want a v2 of this) > > > > > > > > > So make it so that os.chdir() does nothing to avoid this. > > > > > > Note: mock.patch.object() doesn't seem to work in setUpModule(), hence > > > the introduction of a new base class instead. > > > > > > Fixes: 5578d008d9e0 ("kunit: tool: fix running kunit_tool from outside kernel tree") > > > Signed-off-by: Daniel Latypov <dlatypov@google.com> > > > --- > > > > I don't like this: disabling a real system call seems like overkill to > > work around a path issue like this. > > > > Wouldn't it be better to either: > > (a) stop kunit_tool from needing to chdir entirely; or > > a) is doable, but would require plumbing cwd=get_kernel_root_path() to > all the subprocess calls to make, etc. > I'm not sure fixing a internal test-only issue necessarily justifies > taking that path instead of the easier "just add a chdir" we opted for > in 5578d008d9e0 ("kunit: tool: fix running kunit_tool from outside > kernel tree"). > > > (b) have get_absolute_path() / test_data_path() produce an absolute path. > > > > The latter really seems like the most sensible approach: have the > > script read its own path and read files relative to that. > > b) is not that simple, sadly. > > Say I invoke > $ python3 kunit_tool_test.py > then __file__ = kunit_tool_test.py. > > So __file__ is a relative path, but the code assumed it was an > absolute one and any change of directory breaks things. > Working around that would require something like caching the result of > os.path.abspath(__file__) somewhere. So, to clarify, __file__ is a relative path based on the cwd when the script is initially run, right? In any case, caching the result of os.path.abspath(__file__) seems like the most sensible solution to me. There's global state anyway (the current directory), we might as well have it in an explicit variable, IMHO. > > I can see the point about not mocking out something like os.chdir(). > But on the other hand, do we have any other legitimate reason to call > it besides that one place in kunit.py? > If we do have something that relies on doing an os.chdir(), it should > ideally notice that it didn't work and manifest in a unit test failure > somehow. Certainly there doesn't seem to be any other need to chdir() in kunit_tool at the moment, but I could see us doing so when adding other features. More to the point, if both kunit.py and kunit_tool_test.py rely on or manipulate the current directory as part of their state, that seems like it's asking for some trouble down the line. If we use an absolute path for the test data, that's something that seems unlikely to ever need further changes or cause issues. > > Alternatively, we could make get_kernel_root_path() return ""/None to > avoid the chdir call. > kunit.py: if get_kernel_root_path(): > kunit.py: os.chdir(get_kernel_root_path()) > > There'd be no adverse affects atm for stubbing that out, and I don't forsee any. > But if we want to be even safer, then perhaps we have > > def chdir_to_kernel_root(): > ... > > and mock out just that func in the unit test? I'd be okay with this, even if I'd prefer us to use an absolute path for the test_data as well. Having something like this might even give us the opportunity to verify that we're actually trying to change to the kernel directory in cases where we need to, but that seems like it's out-of-scope for a simple fix. -- David
On Tue, Dec 1, 2020 at 8:41 PM David Gow <davidgow@google.com> wrote: > > On Wed, Dec 2, 2020 at 3:00 AM Daniel Latypov <dlatypov@google.com> wrote: > > > > On Mon, Nov 30, 2020 at 11:33 PM David Gow <davidgow@google.com> wrote: > > > > > > On Tue, Dec 1, 2020 at 7:33 AM Daniel Latypov <dlatypov@google.com> wrote: > > > > > > > > get_absolute_path() makes an attempt to allow for this. > > > > But that doesn't work as soon as os.chdir() gets called. > > > > > > Can we explain why this doesn't work? It's because the test_data/ > > > files are accessed with relative paths, so chdir breaks access to > > > them, right? > > > > Correct. > > Because it actually returns a relative path. > > > > (I forgot that I called out that get_absolute_path() gives relative > > paths in the last patch, and not this one. I can update the commit > > desc if we want a v2 of this) > > > > > > > > > > > > > So make it so that os.chdir() does nothing to avoid this. > > > > > > > > Note: mock.patch.object() doesn't seem to work in setUpModule(), hence > > > > the introduction of a new base class instead. > > > > > > > > Fixes: 5578d008d9e0 ("kunit: tool: fix running kunit_tool from outside kernel tree") > > > > Signed-off-by: Daniel Latypov <dlatypov@google.com> > > > > --- > > > > > > I don't like this: disabling a real system call seems like overkill to > > > work around a path issue like this. > > > > > > Wouldn't it be better to either: > > > (a) stop kunit_tool from needing to chdir entirely; or > > > > a) is doable, but would require plumbing cwd=get_kernel_root_path() to > > all the subprocess calls to make, etc. > > I'm not sure fixing a internal test-only issue necessarily justifies > > taking that path instead of the easier "just add a chdir" we opted for > > in 5578d008d9e0 ("kunit: tool: fix running kunit_tool from outside > > kernel tree"). > > > > > (b) have get_absolute_path() / test_data_path() produce an absolute path. > > > > > > The latter really seems like the most sensible approach: have the > > > script read its own path and read files relative to that. > > > > b) is not that simple, sadly. > > > > Say I invoke > > $ python3 kunit_tool_test.py > > then __file__ = kunit_tool_test.py. > > > > So __file__ is a relative path, but the code assumed it was an > > absolute one and any change of directory breaks things. > > Working around that would require something like caching the result of > > os.path.abspath(__file__) somewhere. > > So, to clarify, __file__ is a relative path based on the cwd when the > script is initially run, right? Yes, on my box at least. https://docs.python.org/3/reference/import.html#__file__ doesn't not seem to stipulate an absolute path, either. > > In any case, caching the result of os.path.abspath(__file__) seems > like the most sensible solution to me. There's global state anyway > (the current directory), we might as well have it in an explicit > variable, IMHO. Ok, sent out a v2 and squash this change with the test_data_path() patch. Not really a fan of the adding the global state, but I see your point about there maybe being need for more chdir calls and I don't see a better way of keeping track of the absolute path. > > > > I can see the point about not mocking out something like os.chdir(). > > But on the other hand, do we have any other legitimate reason to call > > it besides that one place in kunit.py? > > If we do have something that relies on doing an os.chdir(), it should > > ideally notice that it didn't work and manifest in a unit test failure > > somehow. > > Certainly there doesn't seem to be any other need to chdir() in > kunit_tool at the moment, but I could see us doing so when adding > other features. More to the point, if both kunit.py and > kunit_tool_test.py rely on or manipulate the current directory as part > of their state, that seems like it's asking for some trouble down the > line. > > If we use an absolute path for the test data, that's something that > seems unlikely to ever need further changes or cause issues. > > > > Alternatively, we could make get_kernel_root_path() return ""/None to > > avoid the chdir call. > > kunit.py: if get_kernel_root_path(): > > kunit.py: os.chdir(get_kernel_root_path()) > > > > There'd be no adverse affects atm for stubbing that out, and I don't forsee any. > > But if we want to be even safer, then perhaps we have > > > > def chdir_to_kernel_root(): > > ... > > > > and mock out just that func in the unit test? > > I'd be okay with this, even if I'd prefer us to use an absolute path > for the test_data as well. Having something like this might even give > us the opportunity to verify that we're actually trying to change to > the kernel directory in cases where we need to, but that seems like > it's out-of-scope for a simple fix. > > -- David
diff --git a/tools/testing/kunit/kunit_tool_test.py b/tools/testing/kunit/kunit_tool_test.py index 497ab51bc170..3fbe1acd531a 100755 --- a/tools/testing/kunit/kunit_tool_test.py +++ b/tools/testing/kunit/kunit_tool_test.py @@ -288,19 +288,17 @@ class StrContains(str): class KUnitMainTest(unittest.TestCase): def setUp(self): path = get_absolute_path('test_data/test_is_test_passed-all_passed.log') - file = open(path) - all_passed_log = file.readlines() - self.print_patch = mock.patch('builtins.print') - self.print_mock = self.print_patch.start() + with open(path) as file: + all_passed_log = file.readlines() + + self.print_mock = mock.patch('builtins.print').start() + self.addCleanup(mock.patch.stopall) + self.linux_source_mock = mock.Mock() self.linux_source_mock.build_reconfig = mock.Mock(return_value=True) self.linux_source_mock.build_um_kernel = mock.Mock(return_value=True) self.linux_source_mock.run_kernel = mock.Mock(return_value=all_passed_log) - def tearDown(self): - self.print_patch.stop() - pass - def test_config_passes_args_pass(self): kunit.main(['config', '--build_dir=.kunit'], self.linux_source_mock) assert self.linux_source_mock.build_reconfig.call_count == 1
* Stop leaking file objects. * Use self.addCleanup() to ensure we call cleanup functions even if setUp() fails. * use mock.patch.stopall instead of more error-prone manual approach Signed-off-by: Daniel Latypov <dlatypov@google.com> --- tools/testing/kunit/kunit_tool_test.py | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) base-commit: b65054597872ce3aefbc6a666385eabdf9e288da