Reflection: add KClass.createInstance

2016-07-12 19:53:30 +03:00
parent 0525b1e6c1
commit 89d69bc7eb
3 changed files with 92 additions and 0 deletions
@@ -0,0 +1,73 @@
+// WITH_REFLECT
+
+import kotlin.reflect.createInstance
+import kotlin.test.assertTrue
+import kotlin.test.fail
+
+// Good classes
+
+class Simple
+class PrimaryWithDefaults(val d1: String = "d1", val d2: Int = 2)
+class Secondary(val s: String) {
+    constructor() : this("s")
+}
+class SecondaryWithDefaults(val s: String) {
+    constructor(x: Int = 0) : this(x.toString())
+}
+class SecondaryWithDefaultsNoPrimary {
+    constructor(x: Int) {}
+    constructor(s: String = "") {}
+}
+
+// Bad classes
+
+class NoNoArgConstructor(val s: String) {
+    constructor(x: Int) : this(x.toString())
+}
+class NoArgAndDefault() {
+    constructor(x: Int = 0) : this()
+}
+class DefaultPrimaryAndDefaultSecondary(val s: String = "") {
+    constructor(x: Int = 0) : this(x.toString())
+}
+class SeveralDefaultSecondaries {
+    constructor(x: Int = 0) {}
+    constructor(s: String = "") {}
+    constructor(d: Double = 3.14) {}
+}
+class PrivateConstructor private constructor()
+object Object
+
+// -----------
+
+inline fun <reified T : Any> test() {
+    val instance = T::class.createInstance()
+    assertTrue(instance is T)
+}
+
+inline fun <reified T : Any> testFail() {
+    try {
+        T::class.createInstance()
+        fail("createInstance should have failed on ${T::class}")
+    } catch (e: Exception) {
+        // OK
+    }
+}
+
+fun box(): String {
+    test<Any>()
+    test<Simple>()
+    test<PrimaryWithDefaults>()
+    test<Secondary>()
+    test<SecondaryWithDefaults>()
+    test<SecondaryWithDefaultsNoPrimary>()
+
+    testFail<NoNoArgConstructor>()
+    testFail<NoArgAndDefault>()
+    testFail<DefaultPrimaryAndDefaultSecondary>()
+    testFail<SeveralDefaultSecondaries>()
+    testFail<PrivateConstructor>()
+    testFail<Object>()
+
+    return "OK"
+}