JSON serialization changed for serde_json::value::RawValue

[psFried]

What happened?

We have some snapshot tests using some structs that include serde_json::value::RawValue fields. These tests started failing after upgrading from insta version 0.14.0 to 0.20.0. Here's an example of the diffs:

   43    43 │           "image": "ghcr.io/foo/bar/source-potato:v1.2.3",
   44       │-          "config": {"some":"config"}
         44 │+          "config": {
         45 │+            "$serde_json::private::RawValue": "{\"some\":\"config\"}"
         46 │+          }
   45    47 │         }
   46    48 │       },
   47    49 │       "bindings": [

Reproduction steps

1. Use insta::assert_json_snapshot(MyStructWithRawValueField); with insta:1.14.0 and commit the snapshot.
2. Upgrade insta dependency
3. Observe failing test

Insta Version

1.14.0 -> 1.20.0

rustc Version

1.64

What did you expect?

I'm not entirely sure what the expected behavior should be here. The new representation actually seems reasonable from the standpoint that equality of a RawValue perhaps out to depend on the actual string representation rather than just the values of the parsed JSON. In other words, the new format causes semantically insignificant differences in the RawValue-wrapped JSON (such as whitespace) to be considered significant when comparing snapshots.

What do you think? Should this be considered a regression or a feature?

[mitsuhiko]

Ah interesting. Serde's in-band signalling strikes again (serde-rs/serde#1463). I did not expect this but now that it happened I would probably prefer to keep it this way.

I believe fundamentally serde needs to find a better way to represent these things and I probably don't want to hack this into this library now to match the behavior.

[psFried]

Makes sense. I'll consider it a 'happy accident' 😁 Thanks for the quick reply.