Cleanup in js modules

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsCallChecker.kt

@@ -92,7 +92,7 @@ public class JsCallChecker(
             val parserScope = JsFunctionScope(JsRootScope(JsProgram("<js checker>")), "<js fun>")
             val statements = parse(code, errorReporter, parserScope)
 
-            if (statements.size() == 0) {
+            if (statements.size == 0) {
                 context.trace.report(ErrorsJs.JSCODE_NO_JAVASCRIPT_PRODUCED.on(argument))
             }
         } catch (e: AbortParsingException) {
@@ -153,8 +153,8 @@ private fun String.offsetOf(position: CodePosition): Int {
     var lineCount = 0
     var offsetInLine = 0
 
-    while (i < length()) {
-        val c = charAt(i)
+    while (i < length) {
+        val c = this[i]
 
         if (lineCount == position.line && offsetInLine == position.offset) {
             return i
@@ -170,7 +170,7 @@ private fun String.offsetOf(position: CodePosition): Int {
         }
     }
 
-    return length()
+    return length
 }
 
 private val KtExpression.isConstantStringLiteral: Boolean

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/jsRenderers.kt

@@ -68,7 +68,7 @@ public fun String.underlineAsText(from: Int, to: Int): String {
     var lineWasMarked = false
 
     for (i in indices) {
-        val c = charAt(i)
+        val c = this[i]
         val mark: Char
 
         mark = when (i) {
@@ -105,7 +105,7 @@ public fun String.underlineAsHtml(from: Int, to: Int): String {
     val underlineEnd = "</u>"
 
     for (i in indices) {
-        val c = charAt(i)
+        val c = this[i]
 
         val mark = when (i) {
             from -> {

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/nativeAnnotationCheckers.kt

@@ -74,7 +74,7 @@ internal abstract class AbstractNativeIndexerChecker(
     override fun additionalCheck(declaration: KtNamedFunction, descriptor: FunctionDescriptor, diagnosticHolder: DiagnosticSink) {
         val parameters = descriptor.getValueParameters()
         val builtIns = descriptor.builtIns
-        if (parameters.size() > 0) {
+        if (parameters.size > 0) {
             val firstParamClassDescriptor = DescriptorUtils.getClassDescriptorForType(parameters.get(0).getType())
             if (firstParamClassDescriptor != builtIns.string &&
                 !DescriptorUtils.isSubclass(firstParamClassDescriptor, builtIns.number)
@@ -83,7 +83,7 @@ internal abstract class AbstractNativeIndexerChecker(
             }
         }
 
-        if (parameters.size() != requiredParametersCount) {
+        if (parameters.size != requiredParametersCount) {
             diagnosticHolder.report(ErrorsJs.NATIVE_INDEXER_WRONG_PARAMETER_COUNT.on(declaration, requiredParametersCount, indexerKind))
         }
 
@@ -114,7 +114,7 @@ internal class NativeSetterChecker : AbstractNativeIndexerChecker(PredefinedAnno
         if (returnType == null || KotlinBuiltIns.isUnit(returnType)) return
 
         val parameters = descriptor.getValueParameters()
-        if (parameters.size() < 2) return
+        if (parameters.size < 2) return
 
         val secondParameterType = parameters.get(1).getType()
         if (secondParameterType.isSubtypeOf(returnType)) return