Add assertNotContains assertion

Author: JavierSegoviaCordoba

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Added
 
 - `assertTrue` and `assertFalse` assertions
+- `assertNotContains` assertion
 
 ### Changed
 

kotlin-test/api/android/kotlin-test.api

@@ -22,3 +22,4 @@ public final class com/javiersc/kotlin/test/StringMatchersKt {
 	public static final fun assertNotEmpty (Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;
 	public static synthetic fun assertNotEmpty$default (Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Ljava/lang/String;
 }
+

kotlin-test/api/jvm/kotlin-test.api

@@ -29,3 +29,4 @@ public final class com/javiersc/kotlin/test/StringMatchersKt {
 	public static final fun assertNotEmpty (Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;
 	public static synthetic fun assertNotEmpty$default (Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Ljava/lang/String;
 }
+

kotlin-test/common/main/kotlin/com/javiersc/kotlin/test/iterableMatchers.kt

@@ -1,18 +1,28 @@
 package com.javiersc.kotlin.test
 
+import kotlin.test.assertContains
+
 public inline fun <reified I : Iterable<T>, reified T : Any> I.assertContains(
     element: T,
     message: String? = null,
 ): I {
-    if (element in this) return this
-    fail(message ?: "Expected to contain $element but did not")
+    assertContains(iterable = this, element = element, message = message)
+    return this
 }
 
 public inline fun <reified I : Iterable<T>, reified T : Any> I.assertCount(
     expectSize: Int,
     message: String? = null,
 ): I = assertSize(expectSize = expectSize, message = message)
 
+public inline fun <reified I : Iterable<T>, reified T : Any> I.assertNotContains(
+    element: T,
+    message: String? = null,
+): I {
+    if (element !in this) return this
+    fail(message ?: "Expected to contain $element but did not")
+}
+
 public inline fun <reified I : Iterable<T>, reified T : Any> I.assertSize(
     expectSize: Int,
     message: String? = null,

kotlin-test/common/test/kotlin/com/javiersc/kotlin/test/IterableMatchersTest.kt

@@ -12,7 +12,11 @@ class IterableMatchersTest {
         val element = 4
         val message = "Custom error message"
         val exception: AssertionError = assertFailsWith { list.assertContains(element, message) }
-        assertTrue(exception.message == message)
+        assertTrue(
+            exception.message ==
+                "Custom error message. Expected the collection to contain the element.\n" +
+                    "Collection <[1, 2, 3]>, element <4>."
+        )
     }
 
     @Test
@@ -37,6 +41,25 @@ class IterableMatchersTest {
         assertTrue(exception.message == "Expected size 2 but was 3")
     }
 
+    @Test
+    fun `assertNotContains should pass when element is not in the iterable`() {
+        listOf(1, 2, 3).assertNotContains(4)
+    }
+
+    @Test
+    fun `assertNotContains should fail when element is in the iterable`() {
+        assertFailsWith<AssertionError> { listOf(1, 2, 3).assertNotContains(2) }
+    }
+
+    @Test
+    fun `assertNotContains should fail with custom message when element is in the iterable`() {
+        val message = "Custom error message"
+        val exception: AssertionError = assertFailsWith {
+            listOf(1, 2, 3).assertNotContains(2, message)
+        }
+        assertTrue(exception.message == message)
+    }
+
     @Test
     fun `assertSize should pass when size matches`() {
         val list: List<Int> = listOf(1, 2, 3)