1 files changed, 10 insertions, 0 deletions
diff --git a/core/src/test/kotlin/model/CompositeSourceSetIDTest.kt b/core/src/test/kotlin/model/CompositeSourceSetIDTest.kt
index ab9a2ab1..472581e7 100644
--- a/core/src/test/kotlin/model/CompositeSourceSetIDTest.kt
+++ b/core/src/test/kotlin/model/CompositeSourceSetIDTest.kt
@@ -2,6 +2,7 @@ package model
 
 import org.jetbrains.dokka.DokkaSourceSetID
 import org.jetbrains.dokka.model.CompositeSourceSetID
+import org.jetbrains.dokka.model.plus
 import kotlin.test.*
 
 class CompositeSourceSetIDTest {
@@ -55,4 +56,13 @@ class CompositeSourceSetIDTest {
             "Expected merged source set id being contained in composite"
         )
     }
+
+    @Test
+    fun `plus operator`() {
+        val composite = DokkaSourceSetID("m1", "s1") + DokkaSourceSetID("m2", "s2") + DokkaSourceSetID("m3", "s3")
+        assertEquals(
+            DokkaSourceSetID("m1+m2+m3", "s1+s2+s3"), composite.merged,
+            "Expected all three source sets being merged in order"
+        )
+    }
 }