`TerminalWriter`, imported recently from `py`, contains its own
incomplete wcwidth (`char_with`/`get_line_width`) implementation. The
`TerminalReporter` also needs this, but uses the external `wcwidth`
package.
This commit brings the `TerminalWriter` implementation up-to-par with
`wcwidth`, moves to implementation to a new file `_pytest._io.wcwidth`
which is used everywhere, and removes the dependency.
The differences compared to the `wcwidth` package are:
- Normalizes the string before counting.
- Uses Python's `unicodedata` instead of vendored Unicode tables. This
means the data corresponds to the Python's version Unicode version
instead of the `wcwidth`'s package version.
- Apply some optimizations.
Works around:
_____ ERROR collecting testing/io/test_saferepr.py _____
src/_pytest/python.py:502: in _importtestmodule
mod = self.fspath.pyimport(ensuresyspath=importmode)
.venv38/lib/python3.8/site-packages/py/_path/local.py:701: in pyimport
__import__(modname)
<frozen importlib._bootstrap>:991: in _find_and_load
???
<frozen importlib._bootstrap>:975: in _find_and_load_unlocked
???
<frozen importlib._bootstrap>:671: in _load_unlocked
???
src/_pytest/assertion/rewrite.py:136: in exec_module
source_stat, co = _rewrite_test(fn, self.config)
src/_pytest/assertion/rewrite.py:288: in _rewrite_test
co = compile(tree, fn, "exec", dont_inherit=True)
E File "…/Vcs/pytest/testing/io/test_saferepr.py", line 45
E None()
E ^
E SyntaxError: 'NoneType' object is not callable; perhaps you missed a comma?
This causes INTERNALERRORs with pytest-django, which uses
`pytest.fail` (derived from `BaseException`) to prevent DB access, when
pytest then tries to e.g. display the `repr()` for a Django `QuerySet`
etc.
Ref: https://github.com/pytest-dev/pytest-django/pull/776
Bruno Oliveira
Ran Benita
Hugo van Kemenade
gdhameeja
Daniel Hahler
Ran Benita
Anthony Sottile