Moshi is faster to decode JSON at runtime, is actively maintained, has a
smaller memory and method footprint, and a slightly smaller APK size.
Moshi also correctly creates default constructor arguments instead of
leaving them null, which was a source of `NullPointerExceptions` when
using Gson.
The conversion broadly consisted of:
- Adding `@JsonClass(generateAdapter = true)` to data classes that
marshall to/from JSON.
- Replacing `@SerializedName(value = ...)` with `@Json(name = ...)`.
- Replacing Gson instances with Moshi in Retrofit, Hilt, and tests.
- Using Moshi adapters to marshall to/from JSON instead of Gson `toJson`
/ `fromJson`.
- Deleting `Rfc3339DateJsonAdapter` and related code, and using the
equivalent adapter bundled with Moshi.
- Rewriting `GuardedBooleanAdapter` as a more generic `GuardedAdapter`.
- Deleting unused ProGuard rules; Moshi generates adapters using code
generation, not runtime reflection.
The conversion surfaced some bugs which have been fixed.
- Not all audio attachments have attachment size metadata. Don't show
the attachment preview if the metadata is missing.
- Some `throwable` were not being logged correctly.
- The wrong type was being used when parsing the response when sending a
scheduled status.
- Exceptions other than `HttpException` or `IoException` would also
cause a status to be resent. If there's a JSON error parsing a response
the status would be repeatedly sent.
- In tests strings containing error responses were not valid JSON.
- Workaround Mastodon a bug and ensure `filter.keywords` is populated,
https://github.com/mastodon/mastodon/issues/29142
a3d45ca9ec