rxlint is a set of lint checks that check your RxJava code. There are currently three checks.


Checks if a RxJava subscriber is handling the onError() callback.

By default, RxJava will throw an OnErrorNotImplemented exception wrapped in an IllegalStateException for every error that is not handled for RxJava 1.x or will call the default uncaught exception handler directly if you are using RxJava 2.x before version 2.0.6.

When subscribing on a Scheduler, like the error will be thrown on the scheduler thread and the stack trace will have no reference to the place where you subscribed.

TL;DR you should handle onError.


Checks that your code keeps a reference to a Subscription (rx 1.x) or Disposable. Not keeping a reference means that you can't unsubscribe() or dispose() at the appropriate times which might lead to memory leaks and crashes.


Checks if an RxJava 2.x operator is using a default scheduler. Operators like delay() do this. This can cause errors on
Android in particular because a sequence like observable.observeOn(mainThread()).delay(10, TimeUnit.SECONDS) will emit the value on the
default computation scheduler, and not the mainThread() scheduler like one might think. If the subscriber is accessing views on any other thread than the main thread, will throw
an exception at runtime. This check is a warning by default.

Third party library support

As of 1.7.0 rxlint supports RxKotlins subscribeBy operator and checking of subscriptions that are managed by AutoDispose.


Adding rxlint to your project is easy, just add the following dependency to your build.gradle:

implementation 'nl.littlerobots.rxlint:rxlint:<latest version>'

Once added to your project an error will be shown like this:

Lint screenshot

If you are calling subscribe() with a Subscriber (rx 1.x) or DisposableXXXSubscriber (rx 2.x) the subscriber is not checked for handling errors, assuming that you'll handle the errors properly.

Ignoring errors

Use the @SuppressLint("RxSubscribeOnError") annotation, lint.xml or use //noinspection AndroidLintCustomError.
Refer to the tools documentation on lint for more info.


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