Filter away timestamps from diffs, increase testing.

[terjekv]

• This PR filters away timestamps from test results via a regexp.
• The timestamps are replaced inline so other content in the same value are retained.
• Adds testing of object history when supported (host, group, atom, role).
• Moves filtering testing to a host.
• Will conflict with Prevent group history from iterating over None. #198, due to having to fix group history here as well.

[pederhan]

Only consider implementing this if you think replace_timestamps() could actually be called with typed values in the future (currently only Any is passed to it).

---

Suggested change

	def replace_timestamps(obj: Any) -> Any:
	from typing import TypeVar
	TSType = TypeVar("TSType", str, list, dict)
	def replace_timestamps(obj: TSType) -> TSType:

This is not perfect, but provides some very rudimentary type checking:

reveal_type(replace_timestamps("2020-01-01T00:00:00.000Z"))
reveal_type(replace_timestamps(["2020-01-01T00:00:00.000Z", "2020-01-01T00:00:00.000Z"]))
reveal_type(replace_timestamps({"foo": "2020-01-01T00:00:00.000Z"}))

% mypy ci
ci/diff.py:27: note: Revealed type is "builtins.str"
ci/diff.py:28: note: Revealed type is "builtins.list[Any]"
ci/diff.py:29: note: Revealed type is "builtins.dict[Any, Any]"

With a more complicated TypeVar we could get rid of the Any from the returned list and dict type annotations, but that's overkill for something that isn't even part of the CLI itself.

[pederhan]

LGTM

[terjekv]

If we're going the typing route, we should probably use a date library and properly parse things, but I'm not sure I see the huge value in this context.