Import AutoValue via Gradle: why api and not implementation?

[mr746866]

In the user guide here, the instruction to import AutoValue states following.

dependencies {
  // Use 'api' rather than 'compile' for Android or java-library projects.
  compile             "com.google.auto.value:auto-value-annotations:1.6"
  annotationProcessor "com.google.auto.value:auto-value:1.6"
}

Is there any specific reason to use api instead of implementation? (In general, use of implementation is preferred over api)

[tbroyer]

See discussion in #606. If compileOnly works for you, then use it, but if you're building a library shared with others (publicly) you'd better use api.

[mr746866]

@tbroyer Can you please explain the consequence of using implementation? I am using it in my Android project and don't see any problem with it.

[tbroyer]

Any annotation with retention class or runtime can cause issues in downstream modules (at compile time, during static analysis, etc.) under some conditions.

Using api on the other hand is mostly harmless. Worst thing is triggering rebuilds (when updating auto-value).

So without going into details in the doc, best status quo is to suggest api.

[eamonnmcmanus]

With Gradle ≥6.7, it's actually best to use compileOnlyApi. We've updated the documentation to reflect that.