Merge pull request #3164 from onflow/bastian/merge-intersections

Handle legacy type getting converted to intersection type

migrations/statictypes/statictype_migration.go

@@ -247,16 +247,31 @@ func (m *StaticTypeMigration) maybeConvertStaticType(staticType, parentType inte
 
 			legacyType := rewrittenIntersectionType.LegacyType
 
+			var mergedIntersections bool
+
 			var convertedLegacyType interpreter.StaticType
 			if legacyType != nil {
 				convertedLegacyType = m.maybeConvertStaticType(legacyType, rewrittenIntersectionType)
-				switch convertedLegacyType.(type) {
+				switch ty := convertedLegacyType.(type) {
 				case nil,
 					*interpreter.CompositeStaticType,
 					interpreter.PrimitiveStaticType:
 					// valid
 					break
 
+				case *interpreter.IntersectionStaticType:
+					// If the legacy type was converted to an intersection type,
+					// then merge it into the resulting intersection type
+
+					legacyType = nil
+					convertedLegacyType = nil
+
+					convertedInterfaceTypes = append(
+						convertedInterfaceTypes,
+						ty.Types...,
+					)
+					mergedIntersections = true
+
 				default:
 					panic(fmt.Errorf(
 						"invalid non-composite/primitive replacement for legacy type in intersection type %s:"+
@@ -273,13 +288,16 @@ func (m *StaticTypeMigration) maybeConvertStaticType(staticType, parentType inte
 			// If the interface set has at least two items,
 			// then force it to be re-stored/re-encoded,
 			// even if the interface types in the set have not changed.
-			if len(rewrittenIntersectionType.Types) >= 2 || convertedInterfaceType || convertedLegacyType != nil {
+			if len(rewrittenIntersectionType.Types) >= 2 ||
+				convertedInterfaceType ||
+				convertedLegacyType != nil ||
+				mergedIntersections {
 
 				result := interpreter.NewIntersectionStaticType(nil, convertedInterfaceTypes)
 
 				if convertedLegacyType != nil {
 					result.LegacyType = convertedLegacyType
-				} else {
+				} else if legacyType != nil {
 					result.LegacyType = legacyType
 				}
 

migrations/statictypes/statictype_migration_test.go

@@ -604,6 +604,93 @@ func TestStaticTypeMigration(t *testing.T) {
 		})
 
 	})
+
+	t.Run("merge converted legacy type when intersection", func(t *testing.T) {
+
+		t.Parallel()
+
+		const compositeQualifiedIdentifier = "S"
+		compositeType := interpreter.NewCompositeStaticType(
+			nil,
+			utils.TestLocation,
+			compositeQualifiedIdentifier,
+			utils.TestLocation.TypeID(nil, compositeQualifiedIdentifier),
+		)
+
+		const interface1QualifiedIdentifier = "SI1"
+		interfaceType1 := interpreter.NewInterfaceStaticType(
+			nil,
+			utils.TestLocation,
+			interface1QualifiedIdentifier,
+			utils.TestLocation.TypeID(nil, interface1QualifiedIdentifier),
+		)
+
+		const interface2QualifiedIdentifier = "SI2"
+		interfaceType2 := interpreter.NewInterfaceStaticType(
+			nil,
+			utils.TestLocation,
+			interface2QualifiedIdentifier,
+			utils.TestLocation.TypeID(nil, interface2QualifiedIdentifier),
+		)
+
+		intersectionType := interpreter.NewIntersectionStaticType(
+			nil,
+			[]*interpreter.InterfaceStaticType{
+				interfaceType1,
+			},
+		)
+		// NOTE: the legacy type is a composite type,
+		// but it will get rewritten to an intersection type
+
+		intersectionType.LegacyType = compositeType
+
+		staticTypeMigration := NewStaticTypeMigration().WithCompositeTypeConverter(
+			func(staticType *interpreter.CompositeStaticType) interpreter.StaticType {
+				if staticType.TypeID != compositeType.TypeID {
+					return nil
+				}
+
+				return interpreter.NewIntersectionStaticType(
+					nil,
+					[]*interpreter.InterfaceStaticType{
+						interfaceType2,
+					},
+				)
+			},
+		)
+
+		storedValue := interpreter.NewTypeValue(
+			nil,
+			interpreter.NewReferenceStaticType(
+				nil,
+				interpreter.UnauthorizedAccess,
+				intersectionType,
+			),
+		)
+
+		actual := migrate(t,
+			staticTypeMigration,
+			storedValue,
+			true,
+		)
+
+		expected := interpreter.NewTypeValue(
+			nil,
+			interpreter.NewReferenceStaticType(
+				nil,
+				interpreter.UnauthorizedAccess,
+				interpreter.NewIntersectionStaticType(
+					nil,
+					[]*interpreter.InterfaceStaticType{
+						interfaceType1,
+						interfaceType2,
+					},
+				),
+			),
+		)
+
+		assert.Equal(t, expected, actual)
+	})
 }
 
 func TestMigratingNestedContainers(t *testing.T) {