[K/JS] Move ES modules logic to a new transformer with IC

js/js.ast/src/org/jetbrains/kotlin/js/backend/JsToStringGenerationVisitor.java

@@ -1329,31 +1329,47 @@ public class JsToStringGenerationVisitor extends JsVisitor {
 
     @Override
     public void visitImport(@NotNull JsImport jsImport) {
-        p.print("import {");
-        boolean isMultiline = jsImport.getElements().size() > 1;
-        p.indentIn();
-        if (isMultiline)
-            newlineOpt();
-        else
-            space();
+        JsImport.Target target = jsImport.getTarget();
 
-        for (JsImport.Element element : jsImport.getElements()) {
-            nameDef(element.getName());
-            JsName alias = element.getAlias();
-            if (alias != null) {
-                p.print(" as ");
-                nameDef(alias);
-            }
+        p.print("import ");
 
-            if (isMultiline) {
-                p.print(',');
+        if (target instanceof JsImport.Target.Default) {
+            nameDef(((JsImport.Target.Default) target).getName());
+        } else if (target instanceof JsImport.Target.All) {
+            p.print("* as ");
+            nameDef(((JsImport.Target.All) target).getAlias());
+        } else if (target instanceof JsImport.Target.Elements) {
+            List<JsImport.Element> elements = ((JsImport.Target.Elements) target).getElements();
+
+            p.print("{");
+            boolean isMultiline = elements.size() > 1;
+            p.indentIn();
+            if (isMultiline)
                 newlineOpt();
-            } else {
+            else
                 space();
+
+            for (JsImport.Element element : elements) {
+                nameDef(element.getName());
+                JsName alias = element.getAlias();
+                if (alias != null) {
+                    p.print(" as ");
+                    nameDef(alias);
+                }
+
+                if (isMultiline) {
+                    p.print(',');
+                    newlineOpt();
+                }
+                else {
+                    space();
+                }
             }
+            p.indentOut();
+            p.print("}");
         }
-        p.indentOut();
-        p.print("} from ");
+
+        p.print(" from ");
         p.print(javaScriptString(jsImport.getModule()));
     }
 

js/js.ast/src/org/jetbrains/kotlin/js/backend/ast/JsImport.kt

@@ -7,8 +7,23 @@ package org.jetbrains.kotlin.js.backend.ast
 
 class JsImport(
     val module: String,
-    val elements: MutableList<Element> = mutableListOf(),
+    val target: Target,
 ) : SourceInfoAwareJsNode(), JsStatement {
+    constructor(module: String, elements: MutableList<Element> = mutableListOf()) : this(module, Target.Elements(elements))
+
+    val elements: MutableList<Element>
+        get() = (target as Target.Elements).elements
+
+    sealed class Target {
+        class Elements(val elements: MutableList<Element>) : Target()
+        class Default(val name: JsName) : Target() {
+            constructor(name: String) : this(JsName(name, false))
+        }
+
+        class All(val alias: JsName) : Target() {
+            constructor(alias: String) : this(JsName(alias, false))
+        }
+    }
 
     class Element(
         val name: JsName,
@@ -25,7 +40,7 @@ class JsImport(
     }
 
     override fun deepCopy(): JsStatement =
-        JsImport(module, elements.map { it }.toMutableList())
+        JsImport(module, target)
 
     override fun traverse(v: JsVisitorWithContext, ctx: JsContext<*>) {
         v.visit(this, ctx)