KTLN-719 Convert string array to int array (#782)

Author: polomos

core-kotlin-modules/core-kotlin-collections-5/src/test/kotlin/com/baeldung/intArrayToStringArray/IntArrayToStringArrayUnitTest.kt

@@ -0,0 +1,46 @@
+package com.baeldung.intArrayToStringArray
+
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertThrows
+
+class IntArrayToStringArrayUnitTest {
+
+    @Test
+    fun `when using toInt then it converts array`() {
+        val stringArray = arrayOf("1", "2", "3", "4", "5")
+        val intArray = stringArray.map { it.toInt() }.toIntArray()
+        assertThat(intArray.all { it is Int }).isTrue()
+        assertThat(intArray).isEqualTo(arrayOf(1,2,3,4,5))
+    }
+
+    @Test
+    fun `when using toInt then exception is thrown`() {
+        val stringArray = arrayOf("1", "2", "3", "four", "5")
+        assertThrows<NumberFormatException> { stringArray.map { it.toInt() } }
+    }
+
+    @Test
+    fun `when using toInt then exception is handled`() {
+        val stringArray = arrayOf("1", "2", "3", "four", "5")
+        val intList = mutableListOf<Int>()
+        for (element in stringArray) {
+            try {
+                val intValue = element.toInt()
+                intList.add(intValue)
+            } catch (e: NumberFormatException) {
+                // Handle the case when provided value is not a number
+            }
+        }
+        val intArray = intList.toIntArray()
+        assertThat(intArray).isEqualTo(arrayOf(1,2,3,5))
+    }
+
+    @Test
+    fun `when using toIntOrNull then it converts array`() {
+        val stringArray = arrayOf("1", "2", "3", "four", "5")
+        val intArray = stringArray.mapNotNull { it.toIntOrNull() }.toIntArray()
+        assertThat(intArray.all { it is Int }).isTrue()
+        assertThat(intArray).isEqualTo(arrayOf(1,2,3,5))
+    }
+}