[Fix #1612] Adding test with fixed collection

Signed-off-by: Francisco Javier Tirado Sarti <ftirados@ibm.com>

Author: fjtirado

impl/test/src/test/java/io/serverlessworkflow/impl/test/WorkflowDefinitionTest.java

@@ -80,6 +80,11 @@ private static Stream<Arguments> provideParameters() {
             Map.of("input", Arrays.asList(1, 2, 3)),
             o -> assertThat(o).isEqualTo(6),
             c -> assertThat(c).isEqualTo(Map.of("incr", Arrays.asList(2, 3, 4)))),
+        args(
+            "workflows-samples/for-sum-fixed.yaml",
+            Map.of(),
+            o -> assertThat(o).isEqualTo(6),
+            c -> assertThat(c).isEqualTo(Map.of("incr", Arrays.asList(2, 3, 4)))),
         args(
             "workflows-samples/switch-then-loop.yaml",
             Map.of("count", 1),

impl/test/src/test/resources/workflows-samples/for-sum-fixed.yaml

@@ -0,0 +1,22 @@
+document:
+  dsl: '1.0.0-alpha5'
+  namespace: test
+  name: for-sum-example
+  version: '0.1.0'
+do:
+  - sumAll:
+      for:
+        each: number
+        in: 
+          - item: 1
+          - item: 2
+          - item: 3
+      do:
+        - accumulate:
+            set:
+              counter: ${.counter+$number.item}
+            export: 
+             as: if .incr==null then {incr:[$number.item+1]} else .incr+=[$number.item+1] end 
+      output:
+        as: .counter
+