Unit testing API: better mapping on JUnit, proper formatting assertion details when message is not specified

#KT-8929 Fixed
Sensible default message for assertion methods.
#KT-8314 Fixed
Provide assertFailsWith also with KClass and reified type argument.

js/js.libraries/src/qunit/core.kt

@@ -5,5 +5,5 @@ package QUnit
  */
 
 native
-public fun ok(actual: Boolean, message: String): Unit = noImpl;
+public fun ok(actual: Boolean, message: String?): Unit = noImpl;
 

js/js.libraries/src/stdlib/testCode.kt

@@ -17,27 +17,15 @@ public var asserter: Asserter = QUnitAsserter()
 
 public class QUnitAsserter(): Asserter {
 
-    public override fun assertTrue(message: String, actual: Boolean) {
+    public override fun assertTrue(lazyMessage: () -> String?, actual: Boolean) {
+        QUnit.ok(actual, lazyMessage())
+    }
+
+    public override fun assertTrue(message: String?, actual: Boolean) {
         QUnit.ok(actual, message)
     }
 
-    public override fun assertEquals(message: String, expected: Any?, actual: Any?) {
-        QUnit.ok(expected == actual, "$message. Expected <$expected> actual <$actual>")
-    }
-
-    public override fun assertNotEquals(message: String, illegal: Any?, actual: Any?) {
-        QUnit.ok(illegal != actual, "$message. Illegal value: <$illegal>")
-    }
-
-    public override fun assertNotNull(message: String, actual: Any?) {
-        QUnit.ok(actual != null, message)
-    }
-
-    public override fun assertNull(message: String, actual: Any?) {
-        QUnit.ok(actual == null, message)
-    }
-
-    public override fun fail(message: String) {
+    public override fun fail(message: String?) {
         QUnit.ok(false, message)
     }
 }