Aside from reworking the internals of test_.py to work well with
inherited TestCase classes, this also provides the two main features
that were the main reason for revamping the test framework
1. ./scripts/test_.py --reentrant
Runs reentrant tests (tests with reentrant=true in the .toml
configuration) under gdb such that the program is killed on every
call to lfs_emubd_prog or lfs_emubd_erase.
Currently this just increments a number of prog/erases to skip, which
means it doesn't necessarily check every possible branch of the test,
but this should still provide a good coverage of power-loss tests.
2. ./scripts/test_.py --gdb
Run the tests and if a failure is hit, drop into GDB. In theory this
will be very useful for reproducing and debugging test failures.
Note this can be combined with --reentrant to drop into GDB on the
exact cycle of power-loss where the tests fail.
- Reworked how permutations work
- Now with global defines as well (apply to all code)
- Also supports lists of different permutation sets
- Added better cleanup in tests and "make clean"
This is the start of reworking littlefs's testing framework based on
lessons learned from the initial testing framework.
1. The testing framework needs to be _flexible_. It was hacky, which by
itself isn't a downside, but it wasn't _flexible_. This limited what
could be done with the tests and there ended up being many
workarounds just to reproduce bugs.
The idea behind this revamped framework is to separate the
description of tests (tests/test_dirs.toml) and the running of tests
(scripts/test.py).
Now, with the logic moved entirely to python, it's possible to run
the test under varying environments. In addition to the "just don't
assert" run, I'm also looking to run the tests in valgrind for memory
checking, and an environment with simulated power-loss.
The test description can also contain abstract attributes that help
control how tests can be ran, such as "leaky" to identify tests where
memory leaks are expected. This keeps test limitations at a minimum
without limiting how the tests can be ran.
2. Multi-stage-process tests didn't really add value and limited what
the testing environment.
Unmounting + mounting can be done in a single process to test the
same logic. It would be really difficult to make this fail only
when memory is zeroed, though that can still be caught by
power-resilient tests.
Requiring every test to be a single process adds several options
for test execution, such as using a RAM-backed block device for
speed, or even running the tests on a device.
3. Added fancy assert interception. This wasn't really a requirement,
but something I've been wanting to experiment with for a while.
During testing, scripts/explode_asserts.py is added to the build
process. This is a custom C-preprocessor that parses out assert
statements and replaces them with _very_ verbose asserts that
wouldn't normally be possible with just C macros.
It even goes as far as to report the arguments to strcmp, since the
lack of visibility here was very annoying.
tests_/test_dirs.toml:186:assert: assert failed with "..", expected eq "..."
assert(strcmp(info.name, "...") == 0);
One downside is that simply parsing C in python is slower than the
entire rest of the compilation, but fortunately this can be
alleviated by parallelizing the test builds through make.
Other neat bits:
- All generated files are a suffix of the test description, this helps
cleanup and means it's (theoretically) possible to parallelize the
tests.
- The generated test.c is shoved base64 into an ad-hoc Makefile, this
means it doesn't force a rebuild of tests all the time.
- Test parameterizing is now easier.
- Hopefully this framework can be repurposed also for benchmarks in the
future.
This is a minor quality of life change to help debugging, specifically
when debugging test failures.
Before, the test framework used hex, while the log output used decimal.
This was slightly annoying to convert between.
Why not output lengths/offset in hex? I don't have a big reason. I find
it easier to reason about lengths in decimal and ids (such as addresses
or block numbers) in hex. But this may just be me.
- Now test errors have correct line reporting! #line directives
are passed to the compiler that reference the relevant line in
the test case shell script.
--- Multi-block directory ---
./tests/test_dirs.sh:109: assert failed with 0, expected 1
lfs_unmount(&lfs) => 1
- Cleaned up the number of implicit global variables provided to
tests. A lot of these were infrequently used and made it difficult
to remember what was provided. This isn't an MCU, so there's very
little cost to stack allocations when needed.
- Minimized the results.py script (previously stats.py) output to
match minimization of test output.
