Merge pull request #127 from jcornaz/feature/improve-isInstanceOf

Allow to call `isInstanceOf` and equivalent assertions on nullable types

AUTHORS.md

@@ -26,4 +26,4 @@
 1. Fabrício Rissetto - [@fabriciorissetto](https://github.com/fabriciorissetto) ([Contributions](https://github.com/MarkusAmshove/Kluent/commits?author=fabriciorissetto))
 1. Vitus Ortner - [@vitusortner](https://github.com/vitusortner) ([Contributions](https://github.com/MarkusAmshove/Kluent/commits?author=vitusortner))
 1. Caleb Brinkman - [@floralvikings](https://github.com/floralvikings) ([Contributions](https://github.com/MarkusAmshove/Kluent/commits?author=floralvikings))
-
+1. Jonathan Cornaz - [@jcornaz](https://github.com/jcornaz) ([Contributions](https://github.com/MarkusAmshove/Kluent/commits?author=jcornaz))

jvm/src/main/kotlin/org/amshove/kluent/BasicBacktick.kt

@@ -14,12 +14,14 @@ infix fun Any?.`should be instance of`(className: Class<*>) = this.shouldBeInsta
 
 infix fun Any?.`should be instance of`(className: KClass<*>) = this.shouldBeInstanceOf(className)
 
-inline fun <reified T : Any> Any.`should be instance of`() = this.shouldBeInstanceOf<T>()
+inline fun <reified T : Any> Any?.`should be instance of`() = this.shouldBeInstanceOf<T>()
 
 infix fun Any?.`should not be instance of`(className: Class<*>) = this.shouldNotBeInstanceOf(className)
 
 infix fun Any?.`should not be instance of`(className: KClass<*>) = this.shouldNotBeInstanceOf(className)
 
+inline fun <reified T : Any> Any?.`should not be instance of`() = this.shouldNotBeInstanceOf<T>()
+
 fun Any?.`should be null`() = this.shouldBeNull()
 
 fun <T : Any> T?.`should not be null`(): T = this.shouldNotBeNull()

jvm/src/main/kotlin/org/amshove/kluent/Reflection.kt

@@ -4,30 +4,29 @@ import org.amshove.kluent.internal.assertFalse
 import org.amshove.kluent.internal.assertTrue
 import org.amshove.kluent.internal.failExpectedActual
 import kotlin.reflect.KClass
-import kotlin.reflect.full.isSubclassOf
 
 infix fun Any?.shouldBeInstanceOf(className: Class<*>) = assertTrue("Expected $this to be an instance of $className", className.isInstance(this))
 
 infix fun Any?.shouldBeInstanceOf(className: KClass<*>) = assertTrue("Expected $this to be an instance of $className", className.isInstance(this))
 
-inline fun <reified T : Any> Any.shouldBeInstanceOf(): T = if (this::class.isInstance(T::class) || this::class.isSubclassOf(T::class)) this as T else throw AssertionError("Expected $this to be an instance or subclass of ${T::class.qualifiedName}")
+inline fun <reified T> Any?.shouldBeInstanceOf(): T = if (this is T) this else throw AssertionError("Expected $this to be an instance or subclass of ${T::class.qualifiedName}")
 
 infix fun Any?.shouldNotBeInstanceOf(className: Class<*>) = assertFalse("Expected $this to not be an instance of $className", className.isInstance(this))
 
 infix fun Any?.shouldNotBeInstanceOf(className: KClass<*>) = assertFalse("Expected $this to not be an instance of $className", className.isInstance(this))
 
-inline fun <reified T : Any> Any.shouldNotBeInstanceOf() = this.shouldNotBeInstanceOf(T::class)
+inline fun <reified T> Any?.shouldNotBeInstanceOf() = if (this !is T) this else throw AssertionError("Expected $this to not be an instance or subclass of ${T::class.qualifiedName}")
 
-infix fun <T : Any> T.shouldHaveTheSameClassAs(other: Any) = apply {
+infix fun <T : Any> T?.shouldHaveTheSameClassAs(other: Any) = apply {
     if (!haveSameClasses(this, other)) {
-        failExpectedActual("Expected objects to have the same class", this::class.qualifiedName!!, other::class.qualifiedName!!)
+        failExpectedActual("Expected objects to have the same class", this?.javaClass?.kotlin?.qualifiedName, other::class.qualifiedName!!)
     }
 }
 
-infix fun <T : Any> T.shouldNotHaveTheSameClassAs(other: Any) = apply {
+infix fun <T : Any> T?.shouldNotHaveTheSameClassAs(other: Any) = apply {
     if(haveSameClasses(this, other)) {
-        failExpectedActual("Expected objects to not have the same class", this::class.qualifiedName!!, other::class.qualifiedName!!)
+        failExpectedActual("Expected objects to not have the same class", this?.javaClass?.kotlin?.qualifiedName, other::class.qualifiedName!!)
     }
 }
 
-private fun haveSameClasses(first: Any, second: Any) = first::class == second::class
+private fun haveSameClasses(first: Any?, second: Any) = first?.javaClass?.kotlin == second::class

jvm/src/test/kotlin/org/amshove/kluent/tests/assertions/reflection/ShouldBeInstanceOfShould.kt

@@ -5,7 +5,6 @@ import org.amshove.kluent.tests.helpclasses.*
 import org.junit.Test
 import kotlin.test.assertFails
 
-
 class ShouldBeInstanceOfShould {
     @Test
     fun passWhenTestingAnObjectWithThePassedClass() {
@@ -40,4 +39,24 @@ class ShouldBeInstanceOfShould {
             val child = base.shouldBeInstanceOf<Child>()
         }
     }
-}
+
+    @Test
+    fun failWhenTestingNullInstance() {
+        val base: Base? = null
+        assertFails {
+            base.shouldBeInstanceOf<Base>()
+        }
+    }
+
+    @Test
+    fun passWhenTestingNullInstanceAgainstNullableType() {
+        val base: Base? = null
+        base.shouldBeInstanceOf<Base?>()
+    }
+
+    @Test
+    fun passWhenTestingNonNullInstanceAgainstCompatibleNullableType() {
+        val base: Base = Base()
+        base.shouldBeInstanceOf<Base?>()
+    }
+}

jvm/src/test/kotlin/org/amshove/kluent/tests/assertions/reflection/ShouldHaveTheSameClassAsShould.kt

@@ -1,6 +1,7 @@
 package org.amshove.kluent.tests.assertions.reflection
 
 import org.amshove.kluent.shouldHaveTheSameClassAs
+import org.amshove.kluent.tests.helpclasses.Base
 import org.junit.Test
 import kotlin.test.assertFails
 
@@ -45,6 +46,16 @@ class ShouldHaveTheSameClassAsShould {
 
         assertFails { firstChild.shouldHaveTheSameClassAs(secondChild) }
     }
+
+    @Test
+    fun failWhenTestingNullInstance() {
+        val base: Base? = null
+        val other = Base()
+
+        assertFails {
+            base.shouldHaveTheSameClassAs(other)
+        }
+    }
 }
 
 interface IInterface

jvm/src/test/kotlin/org/amshove/kluent/tests/assertions/reflection/ShouldNotBeInstanceOfShould.kt

@@ -1,6 +1,8 @@
 package org.amshove.kluent.tests.assertions.reflection
 
+import org.amshove.kluent.shouldBeInstanceOf
 import org.amshove.kluent.shouldNotBeInstanceOf
+import org.amshove.kluent.tests.helpclasses.Base
 import org.amshove.kluent.tests.helpclasses.Circle
 import org.amshove.kluent.tests.helpclasses.Shape
 import org.amshove.kluent.tests.helpclasses.Square
@@ -33,4 +35,22 @@ class ShouldNotBeInstanceOfShould {
         val firstObject: Shape = Circle(10.0)
         assertFails { firstObject.shouldNotBeInstanceOf<Circle>() }
     }
-}
+
+    @Test
+    fun passWhenTestingNullInstance() {
+        val base: Base? = null
+        base.shouldNotBeInstanceOf<Base>()
+    }
+
+    @Test
+    fun failWhenTestingNullInstanceAgainstNullableType() {
+        val base: Base? = null
+        assertFails { base.shouldNotBeInstanceOf<Base?>() }
+    }
+
+    @Test
+    fun failWhenTestingNonNullInstanceAgainstCompatibleNullableType() {
+        val base: Base = Base()
+        assertFails { base.shouldNotBeInstanceOf<Base?>() }
+    }
+}

jvm/src/test/kotlin/org/amshove/kluent/tests/assertions/reflection/ShouldNotHaveTheSameClassAsShould.kt

@@ -1,6 +1,7 @@
 package org.amshove.kluent.tests.assertions.reflection
 
 import org.amshove.kluent.shouldNotHaveTheSameClassAs
+import org.amshove.kluent.tests.helpclasses.Base
 import org.junit.Test
 import kotlin.test.assertFails
 
@@ -45,4 +46,12 @@ class ShouldNotHaveTheSameClassAsShould {
 
         assertFails { intList.shouldNotHaveTheSameClassAs(stringList) }
     }
+
+    @Test
+    fun passWhenTestingNullInstance() {
+        val base: Base? = null
+        val other = Base()
+
+        base.shouldNotHaveTheSameClassAs(other)
+    }
 }