I tried my best to write a custom directive in Apollo Server Express to validate two input type fields. But the code even works but the recording of the mutation already occurs. I appreciate if anyone can help me fix any error in the code below. This is just sample code, I need to test the value in two fields at the same time.
const { SchemaDirectiveVisitor } = require('apollo-server');
const { GraphQLScalarType, GraphQLNonNull, defaultFieldResolver } = require('graphql');
class RegexDirective extends SchemaDirectiveVisitor {
visitInputFieldDefinition(field) {
this.wrapType(field);
}
visitFieldDefinition(field) {
this.wrapType(field);
}
wrapType(field) {
const { resolve = defaultFieldResolver } = field;
field.resolve = async function (source, args, context, info) {
if (info.operation.operation === 'mutation') {
if (source[field.name] === 'error') {
throw new Error(`Find error: ${field.name}`);
}
}
return await resolve.call(this, source, args, context, info);
};
if (
field.type instanceof GraphQLNonNull
&& field.type.ofType instanceof GraphQLScalarType
) {
field.type = new GraphQLNonNull(
new RegexType(field.type.ofType),
);
} else if (field.type instanceof GraphQLScalarType) {
field.type = new RegexType(field.type);
} else {
// throw new Error(`Not a scalar type: ${field.type}`);
}
}
}
class RegexType extends GraphQLScalarType {
constructor(type) {
super({
name: 'RegexScalar',
serialize(value) {
return type.serialize(value);
},
parseValue(value) {
return type.parseValue(value);
},
parseLiteral(ast) {
const result = type.parseLiteral(ast);
return result;
},
});
}
}
module.exports = RegexDirective;