feat: add difference between Flow takeWhile and transformWhile tests [KTLN-870] (#1133)

* feat: add difference between Flow `takeWhile` and `transformWhile` tests

* update val name

* syntax fix

* add new line at EOF

* rename file according to convention

* fix typo

* fix typo

* demo transformation

* Trigger Build

* Trigger Build

* simplify second transformWhile example to be more like takeWhile

* fix test

Author: husam-e

core-kotlin-modules/core-kotlin-flows/src/test/kotlin/com/baeldung/takeWhileTransformWhile/TakeWhileVsTransformWhileUnitTest.kt

@@ -0,0 +1,49 @@
+package com.baeldung.concatenateTwoFlows
+
+import kotlinx.coroutines.flow.*
+import kotlinx.coroutines.runBlocking
+import org.junit.jupiter.api.Assertions
+import org.junit.jupiter.api.Test
+
+class TakeWhileVsTransformWhileUnitTest {
+
+    @Test
+    fun `takeWhile less than 3 returns 1 and 2`() {
+        runBlocking {
+            val numbersFlow = flowOf(1, 2, 3, 4, 5)
+
+            val taken = numbersFlow.takeWhile { it < 3 }.toList()
+
+            Assertions.assertEquals(listOf(1, 2), taken)
+        }
+    }
+
+    @Test
+    fun `transformWhile less than 3 can return 1, 2 and 3`() {
+        runBlocking {
+            val numbersFlow = flowOf(1, 2, 3, 4, 5)
+
+            val transformed = numbersFlow.transformWhile {
+                emit(it)
+                it < 3
+            }.toList()
+
+            Assertions.assertEquals(listOf(1, 2, 3), transformed)
+        }
+    }
+
+    @Test
+    fun `transformWhile can transform elements`() {
+        runBlocking {
+            val numbersFlow = flowOf(1, 2, 3, 4, 5)
+
+            val transformed = numbersFlow.transformWhile {
+                emit("" + it)
+                emit("" + it * 2)
+                it < 3
+            }.toList()
+
+            Assertions.assertEquals(listOf("1", "2", "2", "4", "3", "6"), transformed)
+        }
+    }
+}