Encoding Decoding Map to JSON

[carlos-verdes]

How to reproduce, create a case class with an optional field of type Map:

case class ServerVersion(
    server: String,
    license: String,
    version: String,
    details: Map[String, String] = Map.empty
)

given Schema[ServerVersion] = DeriveSchema.gen[ServerVersion]

Expected test to pass:

      test("Encode/Decode ServerInfo from json using schema") {
        for
          _ <- ZIO.unit
          json = """{ "server": "arango", "license": "community", "version": "3.10.1"}"""
          chunks = Chunk.fromArray(json.getBytes)
          serverInfo <- ZIO.fromEither(
            JsonCodec.decode[ServerVersion](given_Schema_ServerVersion)(chunks)
          )
        yield assertTrue(
          serverInfo == ServerVersion("arango", "community", "3.10.1")
        )
      }

Error: the field details is decoded as Map("" -> "" ) instead of Map.empty:

I tried also with next annotations:

import zio.schema.annotation.{fieldDefaultValue, optionalField}

case class ServerVersion(
    server: String,
    license: String,
    version: String,
    @optionalField
    @fieldDefaultValue[Map[String, String]](Map.empty)
    details: Map[String, String] = Map.empty
)

[carlos-verdes]

I checked the Spec and I see Map is encoded as a sequence of tuples like:

[
  {"key1":  value1},
  {"key2":  value2}
]

However the expectation for me is:

{
  "key1":  value1,
  "key2":  value2
}

I think we should change the full implementation of Map encoder/decoder not just the default values

[carlos-verdes]

Created some tests to reproduce these issues, please let me know if you agree with this Spec before I try to fix the code

[carlos-verdes]

@jdegoes @thinkharderdev @devsprint @tusharmath

This is a big problem to use in any API, I have to receive/pass very often Map[String, String] for extra configuration (for example if you use Spark) and it's really weird that is mapped to json [] instead of {}

I implemented a library for ArangoDB using zio-http and zio-json for serialization and I'm now trying to support zio-schema on top of that (so you can use ArangoDB with any type that has an Schema, and I plan to do dynamic graph queries that bring more than 1 entity just from the Schema abstraction)

[carlos-verdes]

@jdegoes @thinkharderdev @devsprint @tusharmath

I finally had time to implement the full code, to start I only apply the new encoder/decoder when the Map has String as key
As I created a new PR this issue is reopened

We can apply more improvements on next PRs if you think is worth it:

• apply similar logic for any key that is primitive converting the key into String (encoder.contramap(_.toString))
• create a new annotation

[jdegoes]

/bounty $75

[algora-pbc]

💎 $75 bounty • ZIO

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1. Start working: Comment /attempt #447 with your implementation plan
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Attempt	Started (GMT+0)	Solution
🔴 @Samankhalid01	Feb 6, 2024, 7:10:35 PM	WIP

[carlos-verdes]

I think this was fixed on previous PR @jdegoes

[Samankhalid01]

/attempt #447

Options

• Cancel my attempt

[algora-pbc]

@Samankhalid01: Reminder that in 7 days the bounty will become up for grabs, so please submit a pull request before then 🙏

[algora-pbc]

The bounty is up for grabs! Everyone is welcome to /attempt #447 🙌

[Andrapyre]

@adamgfraser , maybe you want to claim the bounty for this, based on #531?

[987Nabil]

@jdegoes this issue still pops up on algora as an open bounty. Maybe you can remove the bounty?