closure() should always produce an OrderedSet (fixes #188)

Author: agarciadom

plugins/org.eclipse.epsilon.eol.engine/src/org/eclipse/epsilon/eol/execute/operations/declarative/ClosureOperation.java

@@ -24,7 +24,6 @@
 import org.eclipse.epsilon.eol.execute.context.FrameType;
 import org.eclipse.epsilon.eol.execute.context.IEolContext;
 import org.eclipse.epsilon.eol.types.EolOrderedSet;
-import org.eclipse.epsilon.eol.types.EolSequence;
 import org.eclipse.epsilon.eol.types.EolType;
 
 public class ClosureOperation extends FirstOrderOperation {
@@ -55,11 +54,8 @@ protected void closure(Collection<Object> closure, Collection<?> source, Paramet
 	@Override
 	public Object execute(Object target, NameExpression operationNameExpression, List<Parameter> iterators, List<Expression> expressions, IEolContext context) throws EolRuntimeException {
 		Collection<?> source = resolveSource(target, iterators, context);
-		if (source.isEmpty()) return new EolSequence<>();
 		EolOrderedSet<Object> accumulator = new EolOrderedSet<Object>();
-		
 		closure(accumulator, source, iterators.get(0), expressions.get(0), context);
-		
 		return accumulator;
 	}
 

tests/org.eclipse.epsilon.eol.engine.test.acceptance/src/org/eclipse/epsilon/eol/engine/test/acceptance/CollectionsTests.eol

@@ -374,6 +374,13 @@ operation testClosure() {
 	assertEquals(flattened, s.closure(e : Sequence|e).asSequence());
 }
 
+@test
+operation testEmptyClosure() {
+	var result = Sequence {}.closure(e | e);
+	assertTrue(result.isEmpty());
+	assertEquals("OrderedSet", result.type.name);
+}
+
 @test
 operation testAggregate() {
 	var s = Sequence{1, 2, 3};