pytest.approx does not work well with JSONSnapshotExtension

[pickfire]

Describe the bug

When JSONSnapshotExtension is used, pytest.approx no longer works since it serializes the ApproxScalar with the original expected value.

To reproduce

1. Install latest pytest and syrupy
2. Add tests/test_hello.py, this random should not affect it since default rel 1e-6

import pytest
import random
from syrupy.extensions.json import JSONSnapshotExtension


@pytest.fixture
def snapshot_json(snapshot):
    return snapshot.use_extension(JSONSnapshotExtension)


def test_snapshot(snapshot_json):
    assert snapshot_json == pytest.approx(1000000 + random.random())

3. Run pytest --snapshot-update
4. See the error

============================= test session starts ==============================
platform linux -- Python 3.12.2, pytest-8.3.2, pluggy-1.5.0
rootdir: /home/project/data_collect
configfile: pyproject.toml
plugins: syrupy-4.7.1
collected 1 item

tests/test_hello.py F

=================================== FAILURES ===================================
________________________________ test_snapshot _________________________________

snapshot_json = "1000000.6413189545 ± 1.0e+00"


    def test_snapshot(snapshot_json):
>       assert snapshot_json == pytest.approx(1000000 + random.random())
E       assert [- snapshot] == [+ received]
E         - "1000000.6413189545 ± 1.0e+00"
E         + "1000000.0143782155 ± 1.0e+00"

tests/test_hello.py:13: AssertionError
--------------------------- snapshot report summary ----------------------------
1 snapshot failed.
=========================== short test summary info ============================
FAILED tests/test_hello.py::test_snapshot - assert [- snapshot] == [+ received]
============================== 1 failed in 0.08s ===============================
Finished running tests!

Environment (please complete the following information):

• OS: Linux f63999551374 5.14.0-480.el9.x86_64 #1 SMP PREEMPT_DYNAMIC Fri Jul 12 20:45:27 UTC 2024 x86_64 GNU/Linux
• Syrupy Version: syrupy-4.7.1
• Python Version: 3.12

Additional context

I had to change it to use f"±{d:.6e}" to get it working so that it will serialize it as str. I think maybe for JSON format we can manually override the _filter?

[noahnu]

Related:

• How to implement assertions with a tolerance #565
• How to use pytest.approx() with syrupy #438 (this issue has a longer discussion in it)