I created a GraphQLScalarType to prevent arguments with empty strings. The issue however is if I don't pass the argument at all when calling the mutation, the mutation succeeds and gives the field a value of null.
Usually, I'd wrap the type in a GraphQLNonNull type e.g
GraphQLNonNull(GraphQLString). But that doesn't work with my custom scalar type.
function validateEmptyStrings(value) {
if (typeof value !== 'string') {
throw new TypeError('Value must be a string')
}
if (value === "") {
throw new TypeError('Value cannot be empty')
}
return value
}
const NonEmptyString = new GraphQLScalarType({
name: 'NonEmptyString',
serialize: validateEmptyStrings,
parseValue: validateEmptyStrings,
})
My mutation below
addClient: {
type: ClientType,
args: {
name: {type: NonEmptyString, required: true},
},
resolve(parent, args) {
const client = new Client ({
name: args.name,
})
return client.save()
}
}
Wrapping the arg 'name' type like GraphQLNonNull(NonEmptyString) doesn't work, and neither does the required: true do anything
