Add test infrastructure for JS source map parser and generator

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

@@ -608,13 +608,9 @@ public class JsToStringGenerationVisitor extends JsVisitor {
         }
 
         p.maybeIndent();
-        beforeNodePrinted(nameRef);
         p.print(nameRef.getIdent());
     }
 
-    protected void beforeNodePrinted(JsNode node) {
-    }
-
     @Override
     public void visitNew(@NotNull JsNew x) {
         p.print(CHARS_NEW);

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

@@ -13,20 +13,24 @@ import java.util.List;
 public final class JsObjectLiteral extends JsLiteral {
     private final List<JsPropertyInitializer> properties;
 
-    private final boolean multiline;
+    private boolean multiline;
 
     public JsObjectLiteral() {
-        this(new SmartList<JsPropertyInitializer>());
+        this(new SmartList<>());
     }
 
     public JsObjectLiteral(boolean multiline) {
-        this(new SmartList<JsPropertyInitializer>(), multiline);
+        this(new SmartList<>(), multiline);
     }
 
     public boolean isMultiline() {
         return multiline;
     }
 
+    public void setMultiline(boolean multiline) {
+        this.multiline = multiline;
+    }
+
     public JsObjectLiteral(List<JsPropertyInitializer> properties) {
         this(properties, false);
     }

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

@@ -18,14 +18,14 @@ import java.util.*;
 public class JsVars extends SourceInfoAwareJsNode implements JsStatement, Iterable<JsVars.JsVar> {
     private final List<JsVar> vars;
 
-    private final boolean multiline;
+    private boolean multiline;
 
     public JsVars() {
-        this(new SmartList<JsVar>(), false);
+        this(new SmartList<>(), false);
     }
 
     public JsVars(boolean multiline) {
-        this(new SmartList<JsVar>(), multiline);
+        this(new SmartList<>(), multiline);
     }
 
     public JsVars(List<JsVar> vars, boolean multiline) {
@@ -34,17 +34,21 @@ public class JsVars extends SourceInfoAwareJsNode implements JsStatement, Iterab
     }
 
     public JsVars(JsVar var) {
-        this(new SmartList<JsVar>(var), false);
+        this(new SmartList<>(var), false);
     }
 
     public JsVars(JsVar... vars) {
-        this(new SmartList<JsVar>(vars), false);
+        this(new SmartList<>(vars), false);
     }
 
     public boolean isMultiline() {
         return multiline;
     }
 
+    public void setMultiline(boolean multiline) {
+        this.multiline = multiline;
+    }
+
     /**
      * A var declared using the JavaScript <code>var</code> statement.
      */
@@ -138,6 +142,7 @@ public class JsVars extends SourceInfoAwareJsNode implements JsStatement, Iterab
     }
 
     @Override
+    @NotNull
     public Iterator<JsVar> iterator() {
         return vars.iterator();
     }