JS: add tests to prove that KT-8003, KT-8318 and KT-12157 are no longer reproducible

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/MiscTest.java

@@ -197,4 +197,8 @@ public final class MiscTest extends AbstractExpressionTest {
     public void testToGeneratorInStdlib() throws Exception {
         checkFooBoxIsOk();
     }
+
+    public void testThrowThrow() throws Exception {
+        checkFooBoxIsOk();
+    }
 }

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/WhenTest.java

@@ -141,4 +141,12 @@ public final class WhenTest extends AbstractExpressionTest {
     public void testWhenEqualsPattern() throws Exception {
         checkFooBoxIsOk();
     }
+
+    public void testWhenWithIfConditionAndOnlyElse() throws Exception {
+        checkFooBoxIsOk();
+    }
+
+    public void testWhenConditionWithReturn() throws Exception {
+        checkFooBoxIsOk();
+    }
 }

js/js.translator/testData/expression/misc/cases/throwThrow.kt

@@ -0,0 +1,16 @@
+package foo
+
+fun test() {
+    throw throw Exception("catch me")
+}
+
+fun box(): String {
+    try {
+        test()
+        error("exception not thrown")
+    }
+    catch (e: Exception) {
+        assertEquals("catch me", e.message)
+    }
+    return "OK"
+}

js/js.translator/testData/expression/when/cases/whenConditionWithReturn.kt

@@ -0,0 +1,13 @@
+package foo
+
+fun test(): Int {
+    return when {
+        (return 23) is Int -> 24
+        else -> 25
+    }
+}
+
+fun box(): String {
+    assertEquals(23, test())
+    return "OK"
+}

js/js.translator/testData/expression/when/cases/whenWithIfConditionAndOnlyElse.kt

@@ -0,0 +1,15 @@
+package foo
+
+var global = ""
+
+fun <T> bar(a: T, i: Int): T {
+    global += "$i"
+    return a
+}
+
+fun box(): String {
+    val x = 3
+    when(if (x == 4) return bar("fail1", 1) else 4) {
+        else -> return bar("OK", 2)
+    }
+}