Fix Must Occur serix validation

serializer/serializable.go

@@ -122,7 +122,9 @@ type ArrayRules struct {
 	Min uint
 	// The max array bound.
 	Max uint
-	// A map of types which must occur within the array.
+	// A map of object types which must occur within the array.
+	// This is only checked on slices of types with an object type set.
+	// In particular, this means this is not checked for byte slices.
 	MustOccur TypePrefixes
 	// The guards applied while de/serializing Serializables.
 	Guards SerializableGuard

serializer/serix/decode.go

@@ -435,6 +435,12 @@ func (api *API) decodeSlice(ctx context.Context, b []byte, value reflect.Value,
 		value.Set(reflect.MakeSlice(valueType, 0, 0))
 	}
 
+	if opts.validation {
+		if err := api.checkArrayMustOccur(value, ts); err != nil {
+			return bytesRead, ierrors.Wrapf(err, "can't deserialize '%s' type", value.Kind())
+		}
+	}
+
 	return bytesRead, nil
 }
 

serializer/serix/encode.go

@@ -319,6 +319,13 @@ func (api *API) encodeSlice(ctx context.Context, value reflect.Value, valueType
 
 		return seri.Serialize()
 	}
+
+	if opts.validation {
+		if err := api.checkArrayMustOccur(value, ts); err != nil {
+			return nil, ierrors.Wrapf(err, "can't serialize '%s' type", value.Kind())
+		}
+	}
+
 	sliceLen := value.Len()
 	data := make([][]byte, sliceLen)
 	for i := 0; i < sliceLen; i++ {

serializer/serix/map_decode.go

@@ -455,6 +455,12 @@ func (api *API) mapDecodeSlice(ctx context.Context, mapVal any, value reflect.Va
 		value.Set(reflect.MakeSlice(valueType, 0, 0))
 	}
 
+	if opts.validation {
+		if err := api.checkArrayMustOccur(value, ts); err != nil {
+			return ierrors.Wrapf(err, "can't deserialize '%s' type", value.Kind())
+		}
+	}
+
 	return nil
 }
 

serializer/serix/map_encode.go

@@ -265,6 +265,12 @@ func (api *API) mapEncodeSlice(ctx context.Context, value reflect.Value, valueTy
 		return nil, ierrors.Wrapf(err, "can't serialize '%s' type", value.Kind())
 	}
 
+	if opts.validation {
+		if err := api.checkArrayMustOccur(value, ts); err != nil {
+			return nil, ierrors.Wrapf(err, "can't serialize '%s' type", value.Kind())
+		}
+	}
+
 	data := make([]any, sliceLen)
 	for i := 0; i < sliceLen; i++ {
 		elemValue := value.Index(i)

serializer/serix/serix.go

@@ -257,6 +257,48 @@ func (api *API) checkSerializedSize(ctx context.Context, value reflect.Value, ts
 	return api.checkMaxByteSize(len(bytes), ts)
 }
 
+// Checks the "Must Occur" array rules in the given slice.
+func (api *API) checkArrayMustOccur(slice reflect.Value, ts TypeSettings) error {
+	if slice.Kind() != reflect.Slice {
+		return ierrors.Errorf("must occur can only be checked for a slice, got value of kind %v", slice.Kind())
+	}
+
+	if ts.arrayRules == nil || len(ts.arrayRules.MustOccur) == 0 {
+		return nil
+	}
+
+	mustOccurPrefixes := make(serializer.TypePrefixes, len(ts.arrayRules.MustOccur))
+	for key, value := range ts.arrayRules.MustOccur {
+		mustOccurPrefixes[key] = value
+	}
+
+	sliceLen := slice.Len()
+	for i := 0; i < sliceLen; i++ {
+		elemValue := slice.Index(i)
+
+		// Get the type prefix of the element by retrieving the type settings.
+		if elemValue.Kind() == reflect.Ptr || elemValue.Kind() == reflect.Interface {
+			elemValue = reflect.Indirect(elemValue.Elem())
+		}
+
+		elemTypeSettings, exists := api.getTypeSettings(elemValue.Type())
+		if !exists {
+			return ierrors.Errorf("missing type settings for %s; needed to check Must Occur rules", elemValue)
+		}
+		_, typePrefix, err := getTypeDenotationAndCode(elemTypeSettings.objectType)
+		if err != nil {
+			return ierrors.WithStack(err)
+		}
+		delete(mustOccurPrefixes, typePrefix)
+	}
+
+	if len(mustOccurPrefixes) != 0 {
+		return ierrors.Wrapf(serializer.ErrArrayValidationTypesNotOccurred, "expected type prefixes that did not occur: %v", mustOccurPrefixes)
+	}
+
+	return nil
+}
+
 // Encode serializes the provided object obj into bytes.
 // serix traverses the object recursively and serializes everything based on the type.
 // If a type implements the custom Serializable interface serix delegates the serialization to that type.

serializer/serix/serix_test.go

@@ -614,3 +614,197 @@ func TestSerixFieldKeyString(t *testing.T) {
 		})
 	}
 }
+
+func TestSerixMustOccur(t *testing.T) {
+	const (
+		ShapeSquare    byte = 100
+		ShapeRectangle byte = 101
+		ShapeTriangle  byte = 102
+	)
+
+	type (
+		Shape interface {
+		}
+		Square struct {
+			Size uint8 `serix:""`
+		}
+		Rectangle struct {
+			Size uint8 `serix:""`
+		}
+		Triangle struct {
+			Size uint16 `serix:""`
+		}
+		Container struct {
+			Shapes []Shape `serix:""`
+		}
+	)
+
+	var shapesArrRules = &serix.ArrayRules{
+		Min: 0,
+		Max: 10,
+		MustOccur: serializer.TypePrefixes{
+			uint32(ShapeSquare):    struct{}{},
+			uint32(ShapeRectangle): struct{}{},
+		},
+		ValidationMode: serializer.ArrayValidationModeNoDuplicates |
+			serializer.ArrayValidationModeLexicalOrdering |
+			serializer.ArrayValidationModeAtMostOneOfEachTypeByte,
+	}
+
+	must(testAPI.RegisterTypeSettings(Triangle{}, serix.TypeSettings{}.WithObjectType(uint8(ShapeTriangle))))
+	must(testAPI.RegisterTypeSettings(Square{}, serix.TypeSettings{}.WithObjectType(uint8(ShapeSquare))))
+	must(testAPI.RegisterTypeSettings(Rectangle{}, serix.TypeSettings{}.WithObjectType(uint8(ShapeRectangle))))
+	must(testAPI.RegisterTypeSettings(Container{}, serix.TypeSettings{}.WithObjectType(uint8(5))))
+
+	must(testAPI.RegisterTypeSettings([]Shape{},
+		serix.TypeSettings{}.WithLengthPrefixType(serix.LengthPrefixTypeAsByte).WithArrayRules(shapesArrRules),
+	))
+
+	must(testAPI.RegisterInterfaceObjects((*Shape)(nil), (*Triangle)(nil)))
+	must(testAPI.RegisterInterfaceObjects((*Shape)(nil), (*Square)(nil)))
+	must(testAPI.RegisterInterfaceObjects((*Shape)(nil), (*Rectangle)(nil)))
+
+	tests := []encodingTest{
+		{
+			name: "ok encoding",
+			source: &Container{
+				Shapes: []Shape{
+					&Square{Size: 10},
+					&Rectangle{Size: 5},
+					&Triangle{Size: 3},
+				},
+			},
+			target:  &Container{},
+			seriErr: nil,
+		},
+		{
+			name: "fail encoding - square must occur",
+			source: &Container{
+				Shapes: []Shape{
+					&Rectangle{Size: 5},
+					&Triangle{Size: 3},
+				},
+			},
+			target:  &Container{},
+			seriErr: serializer.ErrArrayValidationTypesNotOccurred,
+		},
+		{
+			name: "fail encoding - square & rectangle must occur - empty slice",
+			source: &Container{
+				Shapes: []Shape{},
+			},
+			target:  &Container{},
+			seriErr: serializer.ErrArrayValidationTypesNotOccurred,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, tt.run)
+	}
+
+	deSeriTests := []decodingTest{
+		{
+			name: "ok decoding",
+			source: &Container{
+				Shapes: []Shape{
+					&Square{Size: 10},
+					&Rectangle{Size: 5},
+					&Triangle{Size: 3},
+				},
+			},
+			target:    &Container{},
+			deSeriErr: nil,
+		},
+		{
+			name: "fail decoding - square must occur",
+			source: &Container{
+				Shapes: []Shape{
+					&Rectangle{Size: 5},
+					&Triangle{Size: 3},
+				},
+			},
+			target:    &Container{},
+			deSeriErr: serializer.ErrArrayValidationTypesNotOccurred,
+		},
+		{
+			name: "fail decoding - square & rectangle must occur - empty slice",
+			source: &Container{
+				Shapes: []Shape{},
+			},
+			target:    &Container{},
+			deSeriErr: serializer.ErrArrayValidationTypesNotOccurred,
+		},
+	}
+
+	for _, tt := range deSeriTests {
+		t.Run(tt.name, tt.run)
+	}
+}
+
+type encodingTest struct {
+	name    string
+	source  any
+	target  any
+	seriErr error
+}
+
+func (test *encodingTest) run(t *testing.T) {
+	serixData, err := testAPI.Encode(context.Background(), test.source, serix.WithValidation())
+	jsonData, jsonErr := testAPI.JSONEncode(context.Background(), test.source, serix.WithValidation())
+
+	if test.seriErr != nil {
+		require.ErrorIs(t, err, test.seriErr)
+		require.ErrorIs(t, jsonErr, test.seriErr)
+
+		return
+	}
+	require.NoError(t, err)
+	require.NoError(t, jsonErr)
+
+	serixTarget := reflect.New(reflect.TypeOf(test.target).Elem()).Interface()
+	bytesRead, err := testAPI.Decode(context.Background(), serixData, serixTarget)
+
+	require.NoError(t, err)
+	require.Len(t, serixData, bytesRead)
+	require.EqualValues(t, test.source, serixTarget)
+
+	jsonDest := reflect.New(reflect.TypeOf(test.target).Elem()).Interface()
+	require.NoError(t, testAPI.JSONDecode(context.Background(), jsonData, jsonDest))
+
+	require.EqualValues(t, test.source, jsonDest)
+}
+
+type decodingTest struct {
+	name      string
+	source    any
+	target    any
+	deSeriErr error
+}
+
+func (test *decodingTest) run(t *testing.T) {
+	serixData, err := testAPI.Encode(context.Background(), test.source)
+	require.NoError(t, err)
+
+	sourceJSON, err := testAPI.JSONEncode(context.Background(), test.source)
+	require.NoError(t, err)
+
+	serixTarget := reflect.New(reflect.TypeOf(test.target).Elem()).Interface()
+	bytesRead, err := testAPI.Decode(context.Background(), serixData, serixTarget, serix.WithValidation())
+
+	jsonDest := reflect.New(reflect.TypeOf(test.target).Elem()).Interface()
+	jsonErr := testAPI.JSONDecode(context.Background(), sourceJSON, jsonDest, serix.WithValidation())
+
+	if test.deSeriErr != nil {
+		require.ErrorIs(t, err, test.deSeriErr)
+		require.ErrorIs(t, jsonErr, test.deSeriErr)
+
+		return
+	}
+	require.NoError(t, err)
+	require.Len(t, serixData, bytesRead)
+	require.EqualValues(t, test.source, serixTarget)
+
+	require.NoError(t, jsonErr)
+
+	require.EqualValues(t, test.source, jsonDest)
+}