Strange handling of empty json array (possibly zio-schema bug?)

[russwyte]

Describe the bug Routes that produce JSON don't correctly handle empty collections. The resulting JSON should always have a field with an empty JSON array - but instead the field is omitted altogether. To Reproduce See this gist result of run is:

unexpected: {"bars":[1,2,3]}
expected: {"bars":[1,2,3]}
unexpected: {}
expected: {"bars":[]}

Additional context This causes breakage in codecs when lists are not optional and are empty

The gist also shows a work-around that might shed light on a possible fix?

[russwyte]

This is the issue. It seems like the default should be false - as empty collections are valid data.

[russwyte]

Adding this works - but this seems like it should be the default as it is in zio-json and elsewhere

  val routes = Routes(
    unexpected.implement(foo => ZIO.succeed(foo)),
    expected.implement(foo => ZIO.succeed(foo))
  ) @@ CodecConfig.withConfig(CodecConfig(ignoreEmptyCollections = false))

[jdegoes]

@987Nabil Should we change the default here? I too would expect empty collections to be represented in responses (but missing collections to be accepted in requests -- notice the duality).

[987Nabil]

Yeah. I think we should

[notxcain]

Just got bitten by it. It's indeed quite unexpected.

[jdegoes]

/bounty $100

[algora-pbc[bot]]

💎 $100 bounty • ZIO

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Attempt	Started (UTC)	Solution	Actions
🟢 @987Nabil	May 02, 2025, 08:56:13 AM	#3481	Reward
🔴 @Ronyonka	Feb 03, 2025, 11:13:14 AM	WIP

[Ronyonka]

/attempt #3186

Options

• Cancel my attempt

[algora-pbc[bot]]

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

[algora-pbc[bot]]

🎉 The pull request of @987Nabil has been merged. The bounty can be rewarded here

cc @zio

[Tvaroh]

Hey, has this been released? Still drops the empty collection field under zio-http 3.2.0.

[algora-pbc[bot]]

🎉🎈 @987Nabil has been awarded $100 by ZIO! 🎈🎊