Preserve values

[15r10nk]

Fix incorrect values and preserve correct values in the same structure.

This will allow to combine inline-snapshot with libraries like dirty-equals.

Features:

• compares lists, dicts and tuples recursively
• changes only the code which has a different value (with fix)
• updates only the parts which have a different representation (with update)
• lists and tuples are aligned (like in a source diff) and the algorithm tries to maximizes the number of matching values.

[15r10nk]

hi @alexmojaki,

This is the upcoming feature which supports the combination of dirty-equals with inline-snapshots. You could help me with testing this branch for your use cases.

[alexmojaki]

Thanks. I just tried it and found a problem: the order of dict items is not preserved. The code gets updated to reflect the order of the actual value, whereas I'd prefer it used the order in the existing snapshot code where possible, at least for fix (as opposed to update).

[15r10nk]

the order in the following example is preserved:

from inline_snapshot import snapshot


def test_function():
    assert {2: 3, 1: 5} == snapshot({1: 5, 2: 6})

pytest --inline-snapshot=fix

from inline_snapshot import snapshot


def test_function():
    assert {2: 3, 1: 5} == snapshot({1: 5, 2: 3})

I think I implemented the behavior which you described. Changing the order with update is currently not implemented.

Can you give me an example where inline-snapshot does not what you want it to do?

[alexmojaki]

OK, I think the problem is just that I should have uninstalled inline-snapshot before running pip install git+https://github.com/15r10nk/inline-snapshot.git@preserve-values .

[15r10nk]

hi @alexmojaki,

I'm pretty much done with the implementation (documentation still missing). I changed almost the complete implementation and you could do me a favor if you could use the last version of this branch to test it.

[alexmojaki]

I've been using this branch without problems, including in snapshots that contain non-dirty-equals variable expressions. I'm very excited for this to be released and to tell my coworkers about it!

[15r10nk]

@alexmojaki, 0.8.0 has been released. Thank you very much for your feedback. I will clarify the different flags soon when I revise some parts of the documentation.