Optional Any type should allow nil values

[sugovsek]

What happened?

When trying to use Any as an optional input parameter, if you omit it or pass in null, it panics:

interface conversion: interface is nil, not interface {}

The reason seems to be similar to the one in #799 - the relevant line in generated.go:

return ec.resolvers.Mutation().Set(rctx, args["key"].(string), args["value"].(interface{}))

The "value" arg should be checked for nil before the type assertion. If I make this change directly in the generated file, it works as expected.

What did you expect?

Expected no error and the argument to be resolved to nil.

Minimal graphql.schema and models to reproduce

mutation {
    set(key: String!, value: Any): Boolean
}

scalar Any

versions

• gqlgen version? v0.16.0
• go version? 1.17
• dep or go modules? go modules

[AdamJSoftware]

Any news on this? Any potential work arounds?

[sugovsek]

My current workaround is an ugly hack, basically editing the generated file to check the value:

var value interface{}
if args["value"] != nil {
    value = args["value"].(interface{})
}
return ec.resolvers.Mutation().SetValue(rctx, args["key"].(string), value)

I'm planning to dig into the templates and make a proper fix, but I'm not sure when since I'm pretty busy these days.