Merge pull request #27 from AxonFramework/feature/QueryUpdateEmitter-extensions

Add reified generics based extension of QueryUpdateEmitter's emit

Author: sandjelkovic

kotlin/src/main/kotlin/org/axonframework/extensions/kotlin/QueryUpdateEmitterExtensions.kt

@@ -0,0 +1,23 @@
+package org.axonframework.extensions.kotlin
+
+import org.axonframework.queryhandling.QueryUpdateEmitter
+
+/**
+ * Reified version of [org.axonframework.queryhandling.QueryUpdateEmitter.emit] which uses generics
+ * to indicate Query type and Update type.
+ *
+ * Emits given incremental update to subscription queries matching given generic query type and filter.
+ * In order to send nullable updates, use [org.axonframework.queryhandling.QueryUpdateEmitter.emit]
+ * with an [org.axonframework.queryhandling.SubscriptionQueryUpdateMessage]
+ *
+ * @param update    incremental update
+ * @param filter    predicate on query payload used to filter subscription queries
+ * @param [Q]       the type of the query
+ * @param [U]       the type of the update
+ * @see org.axonframework.queryhandling.QueryUpdateEmitter.emit
+ * @author Stefan Andjelkovic
+ */
+inline fun <reified Q, reified U : Any> QueryUpdateEmitter.emit(update: U, noinline filter: (Q) -> Boolean) =
+        this.emit(Q::class.java, filter, update)
+
+

kotlin/src/test/kotlin/org/axonframework/extensions/kotlin/QueryUpdateEmitterExtensionsTest.kt

@@ -0,0 +1,30 @@
+package org.axonframework.extensions.kotlin
+
+import io.mockk.every
+import io.mockk.mockk
+import io.mockk.verify
+import org.axonframework.queryhandling.QueryUpdateEmitter
+import kotlin.test.BeforeTest
+import kotlin.test.Test
+
+/**
+ * Tests [org.axonframework.queryhandling.QueryUpdateEmitter] extensions.
+ *
+ * @author Stefan Andjelkovic
+ */
+internal class QueryUpdateEmitterExtensionsTest {
+    private val subjectEmitter = mockk<QueryUpdateEmitter>()
+    private val exampleQuery = ExampleQuery(2)
+    private val exampleUpdatePayload: String = "Updated"
+
+    @BeforeTest
+    fun before() {
+        every { subjectEmitter.emit(ExampleQuery::class.java, match { it.test(exampleQuery) }, exampleUpdatePayload) } returns Unit
+    }
+
+    @Test
+    fun `Emit extension should invoke correct emit method with a class parameter`() {
+        subjectEmitter.emit<ExampleQuery, String>(exampleUpdatePayload) { it.value == exampleQuery.value }
+        verify { subjectEmitter.emit(ExampleQuery::class.java, match { it.test(exampleQuery) }, exampleUpdatePayload) }
+    }
+}