Ensure Fake classes must be named using Fake and the interface it fakes is detecting error by adding failing cases.

tests/konsist/src/main/kotlin/io/element/android/tests/konsist/failures/FakeWrongClassName.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2024 New Vector Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ * Please see LICENSE in the repository root for full details.
+ */
+
+package io.element.android.tests.konsist.failures
+
+// Make test `Fake classes must be named using Fake and the interface it fakes` fails
+
+interface MyInterface
+
+// This class should be named FakeMyInterface
+class FakeWrongClassName : MyInterface
+
+class MyClass {
+    interface MyFactory
+}
+
+// This class should be named FakeMyClassMyFactory
+class FakeWrongClassSubInterfaceName : MyClass.MyFactory

tests/konsist/src/test/kotlin/io/element/android/tests/konsist/KonsistClassNameTest.kt

@@ -73,6 +73,11 @@ class KonsistClassNameTest {
 
     @Test
     fun `Fake classes must be named using Fake and the interface it fakes`() {
+        var failingCases = 0
+        val failingCasesList = listOf(
+            "FakeWrongClassName",
+            "FakeWrongClassSubInterfaceName",
+        )
         Konsist.scopeFromProject()
             .classes()
             .withNameContaining("Fake")
@@ -84,7 +89,7 @@ class KonsistClassNameTest {
                 val interfaceName = it.name
                     .replace("FakeRust", "")
                     .replace("Fake", "")
-                (it.name.startsWith("Fake") || it.name.startsWith("FakeRust")) &&
+                val result = (it.name.startsWith("Fake") || it.name.startsWith("FakeRust")) &&
                     it.parents().any { parent ->
                         // Workaround to get the parent name. For instance:
                         // parent.name used to return `UserListPresenter.Factory` but is now returning `Factory`.
@@ -93,7 +98,14 @@ class KonsistClassNameTest {
                         val parentName = parent.fullyQualifiedName!!.substringAfter("$packageName.").replace(".", "")
                         parentName == interfaceName
                     }
+                if (!result && it.name in failingCasesList) {
+                    failingCases++
+                    true
+                } else {
+                    result
+                }
             }
+        assertThat(failingCases).isEqualTo(failingCasesList.size)
     }
 
     @Test