The pip-specific Path implementation has been removed, and all its
usages replaced by pathlib.Path. The tmpdir and tmpdir_factory fixtures
are also removed, and all usages are replaced by tmp_path and
tmp_path_factory, which use pathlib.Path.
The pip() function now also accepts pathlib.Path so we don't need to put
str() everywhere. Path arguments are coerced with os.fspath() into str.
The tests are a large consumer of the pip API (both the internal API and
otherwise). By running mypy on tests, we help to:
1. Ensure the internal API is consistent with regards to typing
2. Ensure the tests are representative of real life scenarios as the API
are used correctly.
3. Helps to recognize unnecessary tests that simply pass junk data to
functions which can be caught by the type checker.
4. Make sure test support code in tests/lib/ is correct and consistent.
This is especially important when refactoring such code. For example, if
we were to replace tests/lib/path.py with pathlib.
As a first start, untyped defs are allowed. All existing typing issues
have been resolved. Overtime, we can chip away at untyped defs and
eventually remove the configuration option for stricter type checking of
tests.
The following changes were made to help make mypy pass:
Remove unused record_callback argument from make_wheel() in tests.
Unused since its introduction in
6d8a58f7e1.
Replace toml with tomli_w in tests/functional/test_pep517.py. Unlike the
toml package, tomli_w contains inline typing annotations.
Remove unnecessary make_no_network_finder(). Unnecessary since
bab1e4f8a1 where the _get_pages method was
removed.
Use the tool com2ann to automatically convert most type comments to type
annotations. Some type comments continue to exist where any work beyond
the automatic conversion was required (for example, additional
formatting or circular references).
For additional information on the com2ann tool, see:
https://github.com/ilevkivskyi/com2ann
The typing module has been available since Python 3.5. Guarding the
import has been unnecessary since dropping Python 2.
Some guards remain to either:
- Avoid circular imports
- Importing objects that are also guarded by typing.TYPE_CHECKING
- Avoid mypy_extensions dependency
The stdlib module has been available since Python 3.5 and the
TYPE_CHECKING constant has been available since 3.5.2.
By using stdlib, this removes the need for pip to maintain its own
Python 2 typing compatibility shim.
Now that Python 2 is not supported, the bytes/str boundaries are more
clear and explicit. Using six.ensure_* methods for backwards
compatibility is no longer necessary as the types are known and verified
using mypy.
One exception is tests/lib/wheel.py which allows tests to pass test
setup data as either bytes or str.
The module operations.install.wheel also remains untouched as it is
especially delicate to bytes/str mixups and the current version is
working.
Use pyupgrade to convert simple string formatting to use f-string
syntax. pyupgrade is intentionally timid and will not create an f-string
if it would make the expression longer or if the substitution parameters
are anything but simple names or dotted names.
As we introduce stricter metadata parsing, we will need to ensure that
the wheel files used in our tests are compliant (except in the specific
way that we're testing against).
Currently we have a large number of test cases relying on undocumented or
under-documented wheel files that have various inconsistencies
(incorrect name, missing fields) that are unrelated to the features
actually under test.
With a new wheel builder helper function, we will be able to replace all
of our instances of pre-built wheel test fixtures with dynamically-generated
files in code that are correct by default.
Damian Shaw
Tzu-ping Chung
Jon Dufresne
Pradyun Gedam
Pradyun Gedam
Hugo van Kemenade
Chris Hunt