fix: emit list retrieve for owner-both reverse references

Symptom: retrieving through a Reference association from the child side can be
serialized as an AssociationRetrieveSource, which represents a single object.
When association ownership metadata is explicit, that loses the one-to-many
shape needed by downstream actions.

Root cause: the reverse-reference database-retrieve fallback excluded
AssociationOwnerBoth. The association-source fallback also typed reverse
Reference traversals as a single object even when the start variable was on the
child side.

Fix: use a DatabaseRetrieveSource with an XPath constraint for explicit-owner
reverse Reference traversal over a persistable parent, including owner-both, and
keep legacy association-source fallback list-typed for child-side traversal.

Tests: updated synthetic reverse-reference unit coverage for owner-both,
non-persistable fallback, and unknown-owner fallback, then ran make build and
make test.

Author: hjothamendix

mdl/executor/cmd_microflows_builder_actions.go

@@ -303,7 +303,7 @@ func (fb *flowBuilder) addRetrieveAction(s *ast.RetrieveStmt) model.ID {
 		}
 
 		if assocInfo != nil && assocInfo.Type == domainmodel.AssociationTypeReference &&
-			assocInfo.Owner != domainmodel.AssociationOwnerBoth &&
+			assocInfo.Owner != "" &&
 			assocInfo.parentPersistable &&
 			assocInfo.childEntityQN != "" && startVarType == assocInfo.childEntityQN {
 			// Reverse traversal on Reference: child → parent (one-to-many)
@@ -326,12 +326,18 @@ func (fb *flowBuilder) addRetrieveAction(s *ast.RetrieveStmt) model.ID {
 			}
 			if fb.varTypes != nil {
 				if assocInfo != nil && assocInfo.Type == domainmodel.AssociationTypeReference {
-					// Reference forward traversal: returns single object
+					// Forward Reference traversal returns a single object. Legacy or
+					// non-persistable reverse traversal can still use association
+					// source syntax, but keeps list typing for downstream actions.
 					otherEntity := assocInfo.childEntityQN
 					if startVarType == assocInfo.childEntityQN {
 						otherEntity = assocInfo.parentEntityQN
 					}
-					fb.varTypes[s.Variable] = otherEntity
+					if startVarType == assocInfo.childEntityQN {
+						fb.varTypes[s.Variable] = "List of " + otherEntity
+					} else {
+						fb.varTypes[s.Variable] = otherEntity
+					}
 				} else if assocInfo != nil && assocInfo.Type == domainmodel.AssociationTypeReferenceSet {
 					// ReferenceSet traversal returns a list of the entity on the other side,
 					// not a list typed as the association itself.

mdl/executor/cmd_microflows_builder_retrieve_reverse_test.go

@@ -12,26 +12,26 @@ import (
 	"github.com/mendixlabs/mxcli/sdk/microflows"
 )
 
-func TestAddRetrieveAction_ReverseReferenceOwnerBothUsesAssociationSource(t *testing.T) {
+func TestAddRetrieveAction_ReverseReferenceOwnerBothUsesDatabaseSource(t *testing.T) {
 	fb := newRetrieveAssociationFlowBuilder(domainmodel.AssociationOwnerBoth)
 	fb.varTypes["Child"] = "Sample.Child"
 
 	fb.addRetrieveAction(&ast.RetrieveStmt{
-		Variable:      "Parent",
+		Variable:      "Parents",
 		StartVariable: "Child",
 		Source:        ast.QualifiedName{Module: "Sample", Name: "Parent_Child"},
 	})
 
 	action := onlyRetrieveAction(t, fb)
-	source, ok := action.Source.(*microflows.AssociationRetrieveSource)
+	source, ok := action.Source.(*microflows.DatabaseRetrieveSource)
 	if !ok {
-		t.Fatalf("owner-both reverse retrieve source = %T, want AssociationRetrieveSource", action.Source)
+		t.Fatalf("owner-both reverse retrieve source = %T, want DatabaseRetrieveSource", action.Source)
 	}
-	if source.StartVariable != "Child" || source.AssociationQualifiedName != "Sample.Parent_Child" {
-		t.Fatalf("association source = %#v", source)
+	if source.EntityQualifiedName != "Sample.Parent" || source.XPathConstraint != "[Sample.Parent_Child = $Child]" {
+		t.Fatalf("database source = %#v", source)
 	}
-	if got := fb.varTypes["Parent"]; got != "Sample.Parent" {
-		t.Fatalf("result var type = %q, want Sample.Parent", got)
+	if got := fb.varTypes["Parents"]; got != "List of Sample.Parent" {
+		t.Fatalf("result var type = %q, want List of Sample.Parent", got)
 	}
 }
 
@@ -76,8 +76,31 @@ func TestAddRetrieveAction_ReverseReferenceNonPersistableParentUsesAssociationSo
 	if source.StartVariable != "Child" || source.AssociationQualifiedName != "Sample.Parent_Child" {
 		t.Fatalf("association source = %#v", source)
 	}
-	if got := fb.varTypes["Parents"]; got != "Sample.Parent" {
-		t.Fatalf("result var type = %q, want Sample.Parent", got)
+	if got := fb.varTypes["Parents"]; got != "List of Sample.Parent" {
+		t.Fatalf("result var type = %q, want List of Sample.Parent", got)
+	}
+}
+
+func TestAddRetrieveAction_ReverseReferenceUnknownOwnerPreservesAssociationSource(t *testing.T) {
+	fb := newRetrieveAssociationFlowBuilder("")
+	fb.varTypes["Child"] = "Sample.Child"
+
+	fb.addRetrieveAction(&ast.RetrieveStmt{
+		Variable:      "Parents",
+		StartVariable: "Child",
+		Source:        ast.QualifiedName{Module: "Sample", Name: "Parent_Child"},
+	})
+
+	action := onlyRetrieveAction(t, fb)
+	source, ok := action.Source.(*microflows.AssociationRetrieveSource)
+	if !ok {
+		t.Fatalf("unknown-owner reverse retrieve source = %T, want AssociationRetrieveSource", action.Source)
+	}
+	if source.StartVariable != "Child" || source.AssociationQualifiedName != "Sample.Parent_Child" {
+		t.Fatalf("association source = %#v", source)
+	}
+	if got := fb.varTypes["Parents"]; got != "List of Sample.Parent" {
+		t.Fatalf("result var type = %q, want List of Sample.Parent", got)
 	}
 }