feature request: snapshot name suffix about pytest-insta HOT 4 OPEN

There's another issue with not being able to specify a suffix:

• If my comparisons are as written above (v2 then v1) then when I add a new version it'll go ahead of v2, which means all my fixtures will change.
• if my comparisons are in ascending version order then when I remove an old version then all my fixtures will change.

from pytest-insta.

There's no concept of a "suffix". Either you specify the full name, and the extension is extracted to select the correct snapshot format, or you just specify the extension, and the name is generated for you.

So here snapshot("v2.json") uniquely identifies a specific snapshot for the current test. You can only match it multiple times if all the assertions are supposed to produce the same output. So for example matching the same snapshot in a loop with different inputs won't work.

The closest thing to a suffix would be making pytest-insta recognize a custom extension for your different API versions by defining a custom snapshot format in your conftest.py:

# conftest.py
from pytest_insta import FmtJson

class FmtApiV1(FmtJson):
    extension = ".v1.json"
    
class FmtApiV2(FmtJson):
    extension = ".v2.json"

Then the code you showed earlier will generate a unique name with the custom extension.

Otherwise I'd suggest writing separate tests for v1 and v2, or using a parametrized test with a single snapshot("json") assertion that will run for each API version:

# test_api.py
@pytest.mark.parametrize("api_version", ["v2", "v1"])
async def test_foo(api_version, client):
    if api_version == "v2":
        result = await client.get_new_api()
    else:
        result = await client.get_old_api()
    assert snapshot("json") == result.json()

The generated snapshot name will automatically take into account the parameterized test (e.g.: api__foo__v2__0.json).

The snapshot counter resets for each parameter so the index won't "slide" and invalidate existing snapshots if you add or remove api versions this way.

Depending on your use case you could even bundle this into a fixture and have a hybrid client for tests:

# conftest.py
@pytest.fixture(scope="module", params=["v2", "v1"])
def hybrid_client(request):
    if request.param == "v2":
        return ClientV2()
    else:
        return ClientV1()

# test_api.py
async def test_foo(hybrid_client):
    assert snapshot("json") == (await hybrid_client.get_common_api()).json()
    if isinstance(hybrid_client, ClientV2):
        assert snapshot("json") == (await hybrid_client.get_new_api()).json()
    if isinstance(hybrid_client, ClientV1):
        assert snapshot("json") == (await hybrid_client.get_old_api()).json()

Hope this helps :)

from pytest-insta.

There's no concept of a "suffix". Either you specify the full name, and the extension is extracted to select the correct snapshot format, or you just specify the extension, and the name is generated for you.

So here snapshot("v2.json") uniquely identifies a specific snapshot for the current test. You can only match it multiple times if all the assertions are supposed to produce the same output. So for example matching the same snapshot in a loop with different inputs won't work.

Yep, this is what I wrote in the issue description.

The closest thing to a suffix would be making pytest-insta recognize a custom extension for your different API versions by defining a custom snapshot format in your conftest.py:

# conftest.py
from pytest_insta import FmtJson

class FmtApiV1(FmtJson):
    extension = ".v1.json"
    
class FmtApiV2(FmtJson):
    extension = ".v2.json"

Then the code you showed earlier will generate a unique name with the custom extension.

This would work, but it requires a separate class for every version, which is quite tedious.

Otherwise I'd suggest writing separate tests for v1 and v2, or using a parametrized test with a single snapshot("json") assertion that will run for each API version:

# test_api.py
@pytest.mark.parametrize("api_version", ["v2", "v1"])
async def test_foo(api_version, client):
    if api_version == "v2":
        result = await client.get_new_api()
    else:
        result = await client.get_old_api()
    assert snapshot("json") == result.json()

The generated snapshot name will automatically take into account the parameterized test (e.g.: api__foo__v2__0.json).

This works of course, but imagine that I have a test with with very expensive setup - I don't want to repeat that setup for each test case. I could do something complicated with fixture scopes, but it doesn't work in the most general case (e.g. where something about the test case wants to change the setup, but I still want to test all API versions).

The snapshot counter resets for each parameter so the index won't "slide" and invalidate existing snapshots if you add or remove api versions this way.

Depending on your use case you could even bundle this into a fixture and have a hybrid client for tests:

# conftest.py
@pytest.fixture(scope="module", params=["v2", "v1"])
def hybrid_client(request):
    if request.param == "v2":
        return ClientV2()
    else:
        return ClientV1()

# test_api.py
async def test_foo(hybrid_client):
    assert snapshot("json") == (await hybrid_client.get_common_api()).json()
    if isinstance(hybrid_client, ClientV2):
        assert snapshot("json") == (await hybrid_client.get_new_api()).json()
    if isinstance(hybrid_client, ClientV1):
        assert snapshot("json") == (await hybrid_client.get_old_api()).json()

Hope this helps :)

Again, this doesn't solve for the scenario I describe above :(

from pytest-insta.

Then I'd simply recommend making your own wrapper for implementing a naming scheme that suits your specific use-case:

# conftest.py
@pytest.fixture
def api_snapshot(snapshot: SnapshotFixture):
    d: dict[str, int] = {}

    def wrapper(version: str):
        i = d.setdefault(version, 0)
        d[version] = i + 1
        return snapshot(f"{i}_{version}.json")

    return wrapper

assert api_snapshot("v2") == (await client.get_new_api()).json()
assert api_snapshot("v1") == (await client.get_old_api()).json()

This way you can have independent counters for all API versions without relying on a parametrized test. This will prevent snapshot indices from clashing when you add or remove versions, and you're free to expand it further to meet any additional requirement you might have.

from pytest-insta.