null edge case tests for Monix extensions

Author: sebaciv

core/src/main/scala/com/avsystem/commons/concurrent/ObservableExtensions.scala

@@ -23,9 +23,9 @@ object ObservableExtensions extends ObservableExtensions {
     def headOptL: Task[Opt[T]] = obs.headOptionL.map(_.toOpt)
 
     /**
-      * Returns a [[monix.eval.Task Task]] which emits the first item for which the predicate holds.
+      * Returns a [[monix.eval.Task Task]] which emits the first <b>non-null</b> item for which the predicate holds.
       */
-    def findOptL(p: T => Boolean): Task[Opt[T]] = obs.findL(p).map(_.toOpt)
+    def findOptL(p: T => Boolean): Task[Opt[T]] = obs.findL(e => e != null && p(e)).map(_.toOpt)
 
     /** Suppress the duplicate elements emitted by the source Observable.
       *

core/src/main/scala/com/avsystem/commons/concurrent/TaskExtensions.scala

@@ -18,7 +18,7 @@ trait TaskExtensions {
 object TaskExtensions extends TaskExtensions {
   final class TaskOps[T](private val task: Task[T]) extends AnyVal {
     /**
-      * Like regular `timeout` but [[TimeoutException]] is created lazily (for performance).
+      * Similar to [[Task.timeoutWith]] but exception instance is created lazily (for performance)
       */
     def lazyTimeout(after: FiniteDuration, msg: => String): Task[T] =
       task.timeoutTo(after, Task.raiseError(new TimeoutException(msg)))

core/src/test/scala/com/avsystem/commons/concurrent/ObservableExtensionsTest.scala

@@ -21,12 +21,22 @@ class ObservableExtensionsTest extends AnyFunSuite with Matchers
     }
   }
 
+  test("headOptL - null handling") {
+    Observable.fromIterable(Seq(null, "abc", "xyz")) .headOptL.runToFuture.futureValue shouldBe Opt.Empty
+  }
+
   test("findOptL") {
     forAll { ints: List[Int] =>
       Observable.fromIterable(ints).findOptL(_ > 1).runToFuture.futureValue shouldBe ints.findOpt(_ > 1)
     }
   }
 
+  test("findOptL - null handling") {
+    Observable.fromIterable(Seq(null, "abc", "xyz")).findOptL(_ => true).runToFuture.futureValue shouldBe Opt.some("abc")
+    Observable.fromIterable(Seq(null, null)).findOptL(_ => true).runToFuture.futureValue shouldBe Opt.Empty
+    Observable.fromIterable(Seq(null, "abc", "xyz")).findOptL(_.startsWith("x")).runToFuture.futureValue shouldBe Opt.some("xyz")
+  }
+
   test("distinct") {
     forAll { ints: List[Int] =>
       Observable.fromIterable(ints).distinct.toListL.runToFuture.futureValue shouldBe ints.distinct