IDE-2470: support for JSX spread in transpiler (temporary)

Author: mor-n4

plugins/eu.numberfour.n4js.transpiler.es/src/eu/numberfour/n4js/transpiler/es/transform/JSXTransformation.xtend

@@ -23,6 +23,7 @@ import eu.numberfour.n4jsx.n4JSX.JSXPropertyAttribute
 import eu.numberfour.n4jsx.n4JSX.JSXSpreadAttribute
 
 import static eu.numberfour.n4js.transpiler.TranspilerBuilderBlocks.*
+import eu.numberfour.n4js.utils.N4JSLanguageUtils
 
 /**
  * 
@@ -81,7 +82,7 @@ class JSXTransformation extends Transformation {
 					attr.valueExpressionFromPropertyAttribute)
 			}
 			JSXSpreadAttribute:
-				throw new UnsupportedOperationException
+				_PropertyNameValuePair(N4JSLanguageUtils.SPREAD_IN_OJECT_LITERAL_WORK_AROUND, attr.expression)
 		}
 	}
 

plugins/eu.numberfour.n4js.transpiler/src/eu/numberfour/n4js/transpiler/print/PrettyPrinterSwitch.java

@@ -659,6 +659,11 @@ public Boolean casePropertyAssignmentAnnotationList(PropertyAssignmentAnnotation
 
 	@Override
 	public Boolean casePropertyNameValuePair(PropertyNameValuePair original) {
+		if (N4JSLanguageUtils.SPREAD_IN_OJECT_LITERAL_WORK_AROUND.equals(original.getName())) {
+			write("... ");
+			process(original.getExpression());
+			return DONE;
+		}
 		processPropertyName(original);
 		write(": ");
 		process(original.getExpression());

plugins/eu.numberfour.n4js/src/eu/numberfour/n4js/utils/N4JSLanguageUtils.xtend

@@ -102,6 +102,13 @@ class N4JSLanguageUtils {
 	 */
 	public static final String SYMBOL_IDENTIFIER_PREFIX = ComputedPropertyNameValueConverter.SYMBOL_IDENTIFIER_PREFIX;
 
+	/**
+	 * Temporary hack to be able to support spread operator in the JSX transpiler support.
+	 * This is required, because the ES6 spread operator is not yet supported in the N4JS grammar.
+	 * TODO IDE-2471 remove this and add proper support for spread in object literals to grammar/parser
+	 */
+	public static final String SPREAD_IN_OJECT_LITERAL_WORK_AROUND = "MISSING_SPREAD_WORK_AROUND";
+
 	/**
 	 * If the given function definition is asynchronous, will wrap given return type into a Promise.
 	 * Otherwise, returns given return type unchanged. A return type of <code>void</code> is changed to