feat: LDContext is java.io.Serializable

[joshfriend]

Requirements

• I have added test coverage for new or changed functionality
• I have followed the repository's pull request submission guidelines
• I have validated my changes against all supported platform versions

Describe the solution you've provided

I Added Serializable to any base classes and interfaces needed to make LDContext itself serializable

Describe alternatives you've considered

My workaround for this was to manually serialize the LDContext to json because string is serializable and deserialize it again

Additional context

I was trying to use launchdarkly sdks inside of some gradle tooling that configures build features based on feature flags. To do this I wrote a ValueSource which took the following parameters:

• Feature flag key
• SDK key
• LDContext

And gradle threw an error because LDContext is not serializable, and therefore not allowed as a ValueSourceParameters property.

I'm hoping that code will be open source soon, but for now here's a snippet:

abstract class LDBooleanValueSource: ValueSource<Boolean, LDBooleanValueSource.Params> {
  interface Params : ValueSourceParameters {
    val flagName: Property<String>
    val sdkKey: Property<String>
    val context: Property<LDContext> // Not serializable!
  }

  companion object {
    private val config: LDConfig = LDConfig.Builder().build()

    @JvmStatic
    fun ProviderFactory.launchDarklyBoolean(flagName: String, context: LDContext): Provider<Boolean> {
      return of(LDBooleanValueSource::class.java) {
        it.parameters.flagName.set(flagName)
        it.parameters.sdkKey.set(gradleProperty("launchdarkly.sdkKey"))
        it.parameters.context.set(context)
      }
    }
  }

  private val client by lazy { LDClient(parameters.sdkKey.get(), config) }

  override fun obtain(): Boolean =
    client.allFlagsState(parameters.context.get())
      .getFlagValue(parameters.flagName.get())
      .booleanValue()
}

[tanderson-ld]

Hi @joshfriend and thank you for the contribution. I will try to take a look in the next day or two.