Integer parsed as float64 when passed in as a variable

[s1na]

Hi. We have a simple custom scalar Long which represents a int64 number. I.e.:

type Long int64

// UnmarshalGraphQL unmarshals the provided GraphQL query data.
func (b *Long) UnmarshalGraphQL(input interface{}) error {
        var err error
        switch input := input.(type) {
        case string:
                value, err := strconv.ParseInt(input, 10, 64)
                *b = Long(value)
                return err
        case int32:
                *b = Long(input)
        case int64:
                *b = Long(input)
        default:
                err = fmt.Errorf("unexpected type %T for Long", input)
        }
        return err
}

A long literal in the query works ok, i.e. we can do block(number: 1000000).
But passing it as a variable, i.e. query test($num: Long!) { block(number: $num) } and then "variables": { "num": 1000000 } fails with "unexpected type float64 for Long".

[pavelnikolov]

@s1na This does seem like a problem with your custom type rather than a problem with the GraphQL library. Have you tried adding float64 to the list of possible types? For example:

type Long int64

// UnmarshalGraphQL unmarshals the provided GraphQL query data.
func (b *Long) UnmarshalGraphQL(input interface{}) error {
        var err error
        switch input := input.(type) {
        case string:
                value, err := strconv.ParseInt(input, 10, 64)
                *b = Long(value)
                return err
        case int32:
                *b = Long(input)
        case int64:
                *b = Long(input)
        case float64:
                *b = Long(input)
        default:
                err = fmt.Errorf("unexpected type %T for Long", input)
        }
        return err
}

[pavelnikolov]

Let me know if the above fixes the problem. If you still have issues feel free to give me a failing unit test and I'll try to make it pass.

[s1na]

The reason I opened this issue is the difference in behaviour when the number is passed as part of the query vs. it being passed as a variable. In the latter case it's being parsed as a float64 which causes the error in our custom type. But I don't see why it should be parsed as float64?

[holiman]

block(number: 1000000) is graphql, whereas "variables": { "num": 1000000 } is json.
In the golang json library parser, an unquoted numeric literal is always parsed as float64. Hence the difference. I don't think there's an issue with the graphql-go library.

[pavelnikolov]

I am closing this issue as I don't think that it is related directly to the GraphQL library. I don't think it is worth investing time in making JSON and GraphQL parsing the same.