KT-2752: refactor NameSuggestion, change rules for determining name stability and applying mangling

js/js.translator/testData/box/multiModule/privateInterfaceNameClash.kt

@@ -0,0 +1,54 @@
+// MODULE: lib1
+// FILE: lib1.kt
+package lib1
+
+interface A {
+    private fun foo() = "A.foo"
+
+    fun bar() = foo()
+}
+
+// MODULE: lib2
+// FILE: lib2.kt
+package lib2
+
+interface B {
+    private fun foo() = "B.foo"
+
+    fun bar() = foo()
+}
+
+// MODULE: main(lib1,lib2)
+// FILE: main.kt
+package main
+
+import lib1.A
+import lib2.B
+
+class Derived1 : A, B {
+    override fun bar() = super<A>.bar()
+}
+
+class Derived2 : A, B {
+    override fun bar() = super<B>.bar()
+}
+
+// NOTE. This test is fragile, it may fail due to unexpected (and correct) changes in algorithm that assigns
+// unique identifiers to non-public declarations. However, we don't see any way of doing such test so that
+// it won't report false positives eventually. So be patient and just update this test whenever you changed
+// algorithm of assigning unique identifiers.
+// Please, check that A.foo and B.foo have different JS names.
+private fun checkJsNames(o: dynamic): Boolean = "foo_2pru9n\$_0" in o && "foo_2psha1\$_0" in o
+
+fun box(): String {
+    val a = Derived1()
+    if (a.bar() != "A.foo") return "fail1: ${a.bar()}"
+
+    val b = Derived2()
+    if (b.bar() != "B.foo") return "fail2: ${b.bar()}"
+
+    if (!checkJsNames(a)) return "fail3"
+    if (!checkJsNames(b)) return "fail4"
+
+    return "OK"
+}