Repository navigation
Move Buffered tests from test_io to test_bufio #138013
Description
Feature or enhancement
Proposal:
test_io is currently over 5000 lines long and tests a range of behaviors of lots of distinct io components. Some work to make it more modular has happened over time and there are a number of tests for specific subsets of io behavior (see: https://github.com/python/cpython/blob/main/Lib/test/test_io.py#L3-L13), including one for Buffered I/O (test_bufio.py, 74 lines currently)
About 1200 lines of test_io are Buffered I/O specific tests which are well isolated / can be moved relatively easily (BufferedReaderTest, BufferedWriterTest, BufferedRWPairTest, and BufferedRandomTest as well as their Py*/C* variants). I'd like to move them from test_io to test_bufio to make it simpler/faster to iterate / test / validate Buffered I/O behavior.
Has this already been discussed elsewhere?
This is a minor feature, which does not need previous discussion elsewhere
Links to previous discussion of this feature:
No response
Linked PRs
- gh-138013: Move test.test_io to be a module #138153
- gh-138013: Move I/O tests to test_io #138365
- gh-138013: Remove
test_ioload_tests namespace manipulation #138366 - gh-138013: Move I/O test infrastructre to test_io.utils #138475
- gh-138013: Remove load_tests in test_io.test_general #138771
- gh-138013: Split SignalsTest from test_io.test_general #139079
- gh-138013: Split TextIO tests from test_io.test_general #139173
- gh-138013: Split BufferedIO tests from test_io.test_general #139454
Activity
pythongh-138013: Remove `test_io` load_tests namespace manipulation
pythongh-138013: Remove `test_io` load_tests namespace manipulation
cmaloney commentedon Sep 2, 2025
This set of changes takes
./python -m test test_io -uall,walltime,largefile,extralargefile -M16G -j8from ~34.5s -> ~31.6s for me (64 bit linux workstation).That should help reduce the CI long tail a bit (
test_ioon refleaks builds is often among the "10 slowest tests"). The reduced runtime is largely from increased parallelism (buffered tests run in parallel with othertest_iotests now). If you want to test locally, that's the two outstanding PRs + one commit to do the split (cmaloney@cca2b2e)gh-138013: Move I/O tests to test_io (#138365)
gh-138013: Remove `test_io` load_tests namespace manipulation (#138366)
pythongh-138013: Move buffered tests to test_bufferedio
pythongh-138013: Make ``test.test_io`` into a package (python#138153)
pythongh-138013: Move I/O tests to test_io (python#138365)
pythongh-138013: Remove `test_io` load_tests namespace manipulation (p…
pythongh-138013: Remove load_tests in test_io.test_general
gh-138013: Move I/O test infrastructre to test_io.utils (#138475)
gh-138013: Remove load_tests in test_io.test_general (#138771)
pythongh-138013 Split SignalsTest from test_io.test_general
pythongh-138013 Split SignalsTest from test_io.test_general
pythongh-138013 Split SignalsTest from test_io.test_general
pythongh-138013: Split TextIO tests from test_general
pythongh-138013: Split TextIO tests from test_general
gh-138013: Split SignalsTest from test_io.test_general (#139079)
pythongh-138013: Split TextIO tests from test_general
gh-138013: Split TextIO tests from test_io.test_general (#139173)
vstinner commentedon Sep 30, 2025
Can we close this issue? Or do you plan to split more tests?
pythongh-138013: Split buffered tests out
pythongh-138013: Split buffered tests out
pythongh-138013: Split BufferedIO tests from test_io.test_general
cmaloney commentedon Sep 30, 2025
One final split then done GH-139454
gh-138013: Split BufferedIO tests from test_io.test_general (#139454)
vstinner commentedon Oct 1, 2025
Nice work, thanks @cmaloney!
cmaloney commentedon Oct 1, 2025
Thanks for reviewing!