StringBuilder builder and appendln

js/js.libraries/src/core/javalang.kt

@@ -40,7 +40,7 @@ public trait Comparable<T> {
 library
 public trait Appendable {
     public open fun append(csq: CharSequence?): Appendable
-    //public open fun append(csq: CharSequence?, start: Int, end: Int): Appendable
+    public open fun append(csq: CharSequence?, start: Int, end: Int): Appendable
     public open fun append(c: Char): Appendable
 }
 
@@ -48,8 +48,7 @@ library
 public class StringBuilder() : Appendable {
     override fun append(c: Char): StringBuilder = js.noImpl
     override fun append(csq: CharSequence?): StringBuilder = js.noImpl
-    //TODO
-    //override fun append(csq: CharSequence?, start: Int, end: Int): StringBuilder = js.noImpl
+    override fun append(csq: CharSequence?, start: Int, end: Int): StringBuilder = js.noImpl
     public fun append(obj: Any?): StringBuilder = js.noImpl
     public fun reverse(): StringBuilder = js.noImpl
     override fun toString(): String = js.noImpl

js/js.tests/test/org/jetbrains/k2js/test/semantics/StdLibStringBuilderTest.java

@@ -0,0 +1,10 @@
+package org.jetbrains.k2js.test.semantics;
+
+import junit.framework.Test;
+
+@SuppressWarnings("JUnitTestCaseWithNoTests")
+public final class StdLibStringBuilderTest extends JsUnitTestBase {
+    public static Test suite() throws Exception {
+        return createTestSuiteForFile("libraries/stdlib/test/text/StringBuilderTest.kt");
+    }
+}

js/js.tests/test/org/jetbrains/k2js/test/semantics/StdLibStringTest.java

@@ -0,0 +1,10 @@
+package org.jetbrains.k2js.test.semantics;
+
+import junit.framework.Test;
+
+@SuppressWarnings("JUnitTestCaseWithNoTests")
+public final class StdLibStringTest extends JsUnitTestBase {
+    public static Test suite() throws Exception {
+        return createTestSuiteForFile("libraries/stdlib/test/text/StringTest.kt");
+    }
+}

js/js.translator/src/org/jetbrains/k2js/config/Config.java

@@ -139,6 +139,7 @@ public abstract class Config {
             "/kotlin/Ranges.kt",
             "/kotlin/Numbers.kt",
             "/kotlin/text/Strings.kt",
+            "/kotlin/text/StringBuilder.kt",
             "/kotlin/dom/Dom.kt",
             "/kotlin/test/Test.kt"
     );

js/js.translator/testData/kotlin_lib.js

@@ -649,8 +649,15 @@
         function () {
             this.string = "";
         }, {
-        append: function (obj) {
-            this.string = this.string + obj.toString();
+        append: function (obj, from, to) {
+            if (from == undefined && to == undefined) {
+                this.string = this.string + obj.toString();
+            } else if (to == undefined) {
+                this.string = this.string + obj.toString().substring(from);
+            } else {
+                this.string = this.string + obj.toString().substring(from, to);
+            }
+
             return this;
         },
         reverse: function () {