feat: add Flipt provider

[liran2000]

add Flipt provider.

See readme for details.

@markphelps you are welcome to review from Flipt perspective.

@toddbaert you are welcome to review from OpenFeature perspective.

[liran2000]

@markphelps build passed locally but failing here since flipt-java is built with Java 11, and this job is build with Java 8.
Possibly flipt-java can have a Java 8 release, for example 0.2.11-java8 ?

[markphelps]

@markphelps build passed locally but failing here since flipt-java is built with Java 11, and this job is build with Java 8. Possibly flipt-java can have a Java 8 release, for example 0.2.11-java8 ?

@liran2000 yeah I will try to setup a Java 8 release. Our Java SDK is actually autogenerated, so hopefully there arent any Java 9+ specific features (been a long time since I've written Java)

[markphelps]

@liran2000 I dont think it's going to work with Java 8: https://github.com/flipt-io/flipt-java/actions/runs/6355901633/job/17264700354

Looks like our SDK requires some functionality that isn't in 8 (Map.of)

[markphelps]

is it possible to update this job to a more recent version of Java?

[liran2000]

Looks like our SDK requires some functionality that isn't in 8 (Map.of)

I can try to take a look at Flipt SDK to see what is the amount of non compliant code.

is it possible to update this job to a more recent version of Java?

As a library, if it compiles with newer Java version it will break Java 8 compatability, and will require newer Java version from all usages.

[toddbaert]

is it possible to update this job to a more recent version of Java?

Lots of enterprises are (unfortunately) still using Java 1.8, which is why both the SDK and contribs target (and use) it.

@markphelps I suspect the biggest challenge will be getting your tooling/plugins/etc working with 8, though that's not strictly necessary. You should be able to target 1.8 and then you'll be only making code changes, which from 11 to 8 shouldn't be too huge 😬 ... but obviously it depends on your 11 language feature usage.

[liran2000]

@markphelps opened PR for Flipt SDK.
There seems to be only the one mentioned code place to update, so changing the main branch and release seems simpler than a separate release for Java 8.
You can review, merge and release it if you agree for proceeding. Notice the release job itself has to compile with Java 8 too.
Thanks

[markphelps]

Hi @liran2000 ! We just released a new version which uses the sourceCompatibility / targetCompatibility features of gradle. Ive been told that this should be enough so that the JAR/class files should target Java 8.

Would it be possible to update the Flipt SDK to 0.2.13? https://central.sonatype.com/artifact/io.flipt/flipt-java ?

cc @dsinghvi

[liran2000]

Hi @liran2000 ! We just released a new version which uses the sourceCompatibility / targetCompatibility features of gradle. Ive been told that this should be enough so that the JAR/class files should target Java 8.

Would it be possible to update the Flipt SDK to 0.2.13? https://central.sonatype.com/artifact/io.flipt/flipt-java ?

cc @dsinghvi

Thanks for the effort, the output JAR classes are now "Java 8", I tried it, it failed since the source code still have Java 8+ code. Failure is in the test, which is like a runtime test:

dev.openfeature.contrib.providers.flipt.FliptProviderTest
Error: dev.openfeature.contrib.providers.flipt.FliptProviderTest -- Time elapsed: 1.066 s <<< ERROR!
java.lang.NoSuchMethodError: java.util.Map.of(Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)Ljava/util/Map;

In the link provided, it is mentioned:

"Additionally, the source code cannot contain lambda expressions or any feature not available in Java 6."

I don't see how it can compile and run with Java 8 without removing the incompatible Map.of from source code.

[dsinghvi]

@liran2000 thanks for testing -- this was oversight on my part. Will rerelease a version of the generator today.

[markphelps]

looks great once the Flipt Java SDK is updated! thank you @liran2000 !!

[toddbaert]

I'm ready to approve once the above unresolved comments are resolved.

[liran2000]

I'm ready to approve once the above unresolved comments are resolved.

Comments are addressed in recents commits, can you check latest code?

[toddbaert]

I'm ready to approve once the above unresolved comments are resolved.

Comments are addressed in recents commits, can you check latest code?

Oh I'm sorry, I kept following sent to old permalinks to previous commits! Yes I see they are resolved. Approving!

[markphelps]

Thank you @liran2000 for all your hard work on this!!! And thank you @toddbaert for the review. Will update our docs as well to mention this new provider