Function checkSchema

worker/mutation.go:380–458

(s *pb.SchemaUpdate)

	return false
}
func checkSchema(s *pb.SchemaUpdate) error {
	if s == nil {
		return errors.Errorf("Nil schema")
	}

	if x.ParseAttr(s.Predicate) == "" {
		return errors.Errorf("No predicate specified in schema mutation")
	}

	if x.IsInternalPredicate(s.Predicate) {
		return errors.Errorf("Cannot create user-defined predicate with internal name %s",
			x.ParseAttr(s.Predicate))
	}

	if s.Directive == pb.SchemaUpdate_INDEX && !schema.HasTokenizerOrVectorIndexSpec(s) {
		return errors.Errorf("Tokenizer must be specified while indexing a predicate: %+v", s)
	}

	if schema.HasTokenizerOrVectorIndexSpec(s) && s.Directive != pb.SchemaUpdate_INDEX {
		return errors.Errorf("Directive must be SchemaUpdate_INDEX when a tokenizer is specified")
	}

	typ := types.TypeID(s.ValueType)
	if typ == types.UidID && s.Directive == pb.SchemaUpdate_INDEX {
		// index on uid type
		return errors.Errorf("Index not allowed on predicate of type uid on predicate %s",
			x.ParseAttr(s.Predicate))
	} else if typ != types.UidID && s.Directive == pb.SchemaUpdate_REVERSE {
		// reverse on non-uid type
		return errors.Errorf("Cannot reverse for non-uid type on predicate %s",
			x.ParseAttr(s.Predicate))
	}

	// If schema update has upsert directive, it should have index directive.
	if s.Upsert && len(s.Tokenizer) == 0 && !s.Unique {
		return errors.Errorf("Index tokenizer is mandatory for: [%s] when specifying @upsert directive",
			x.ParseAttr(s.Predicate))
	}

	if s.Unique {
		ctx := context.WithValue(context.Background(), schema.IsWrite, false)
		prevSchema, _ := schema.State().Get(ctx, s.Predicate)
		if err := validateSchemaForUnique(prevSchema, s); err != nil {
			return err
		}
	}

	t, err := schema.State().TypeOf(s.Predicate)
	if err != nil {
		// No schema previously defined, so no need to do checks about schema conversions.
		return nil
	}

	// schema was defined already
	switch {
	case t.IsScalar() && (t.Enum() == pb.Posting_PASSWORD || s.ValueType == pb.Posting_PASSWORD):
		// can't change password -> x, x -> password
		if t.Enum() != s.ValueType {