In Python, if module A defines a name `name`, and module B does `import
name from A`, then another module C can `import name from B`.
Sometimes it is intentional -- module B is meant to "reexport" `name`.
But sometimes it is just confusion/inconsistency on where `name` should
be imported from.
mypy has a flag `--no-implicit-reexport` which puts some order into
this. A name can only be imported from a module if
1. The module defines the name
2. The module's `__all__` includes the name
3. The module imports the name as `from ... import .. as name`.
This flag is included in mypy's `--strict` flag.
I like this flag, but I realize it is a bit controversial, and in
particular item 3 above is a bit unfriendly to contributors who don't
know about it. So I didn't intend to add it to pytest.
But while investigating issue 7589 I came upon mypy issue 8754 which
causes `--no-implicit-reexport` to leak into installed libraries and
causes some unexpected typing differences *in pytest* if the user uses
this flag.
Since the diff mostly makes sense, let's just conform to it.
This has been there since as far as the git history goes (2007), is not
covered by any test, and says "Buggy python version consider upgrading".
Hopefully everyone have upgraded...
* Turn ReprTraceback into attrs class
* Use attr.asdict with serialize_repr_{crash,traceback}
* Turn ReprFileLocation into attrs class, convert py.path.local
* Use code highlighting if pygments is installed
* Use colorama constants instead of bare ascii codes
Could not find the exact equivalent of 'hl-reset' code using colorama
constants though.
* Refactor ASCII color handling into a fixture
* Revert back to using explicit color codes
* In Python 3.5 skip rest of tests that require ordered markup in colored output
Previously this would be turned via `py.path.local("")` into the current
working directory.
This appears to be what `fspath = fn and py.path.local(fn) or None`
tries to avoid in `getfslineno`'s `TypeError` handling already, if
`Code` would raise it.
Everything was using `_pytest.compat.getfslineno` basically, which
wrapped `_pytest._code.source.getfslineno`.
This moves the extra code from there into it directly, and uses the
latter everywhere.
This helps to eventually remove the one in compat eventually, and also
causes less cyclic imports.
These are more "dirty" than the previous batch (that's why they were
left out). The trouble is that `compile` can return either a code object
or an AST depending on a flag, so we need to add an overload to make the
common case Union free. But it's still worthwhile.