Fix error "External class constructor cannot have a property parameter" (#118)

Author: epabst

src/main/kotlin/ts2kt/TsClassToKt.kt

@@ -34,7 +34,15 @@ class TsClassToKt(
 
     override fun visitConstructorDeclaration(node: ConstructorDeclaration) {
         val paramsOverloads = node.parameters.toKotlinParamsOverloads(typeMapper)
-        paramsOfConstructors.addAll(paramsOverloads)
+        val nonVarParamOverloads = paramsOverloads.map { params ->
+            params.map { param ->
+                if (param.isVar) {
+                    addVariable(null, param.name.value, param.type.type, isVar = param.isVar)
+                }
+                param.copy(isVar = false)
+            }
+        }
+        paramsOfConstructors.addAll(nonVarParamOverloads)
 
         assert(node.body == null, "A constructor in declarations file should not have body, constructor in '${this.name}")
     }

testData/class/constructor/withPropertyDeclaration.d.kt

@@ -1,4 +1,9 @@
 package withPropertyDeclaration
 
-external open class Foo(open var x: Any)
-external open class Bar(open var n: Number, open var a: Any)
+external open class Foo(x: Any) {
+    open var x: Any = definedExternally
+}
+external open class Bar(n: Number, a: Any) {
+    open var n: Number = definedExternally
+    open var a: Any = definedExternally
+}