[Proposal] Panic message can be improve when schema type name is not compatible

[louis993546]

Expected Behaviour

1. Enter the 1st schema below
2. go run github.com/99designs/gqlgen init
3. Panic on why having type Time is not a good idea

Actual Behavior

1. Enter the 1st schema below
2. go run github.com/99designs/gqlgen init
3. Panic with this:

panic: interface conversion: types.Type is *types.Signature, not *types.Named

goroutine 1 [running]:
github.com/99designs/gqlgen/codegen.(*builder).bindField(0xc000225668, 0xc000314a00, 0xc000144990, 0x0, 0x0)
        /home/louis/go/pkg/mod/github.com/99designs/gqlgen@v0.8.1/codegen/field.go:110 +0x1011
github.com/99designs/gqlgen/codegen.(*builder).buildField(0xc000225668, 0xc000314a00, 0xc0000d3180, 0x0, 0xe91a00, 0x0)
        /home/louis/go/pkg/mod/github.com/99designs/gqlgen@v0.8.1/codegen/field.go:64 +0x31d
github.com/99designs/gqlgen/codegen.(*builder).buildObject(0xc000225668, 0xc00045ce40, 0x9d3c36, 0x6, 0x0)
        /home/louis/go/pkg/mod/github.com/99designs/gqlgen@v0.8.1/codegen/object.go:72 +0x4d4
github.com/99designs/gqlgen/codegen.BuildData(0xc0001c40c0, 0xaad6e0, 0xc000119120, 0x0)
        /home/louis/go/pkg/mod/github.com/99designs/gqlgen@v0.8.1/codegen/data.go:83 +0x47f
github.com/99designs/gqlgen/api.Generate(0xc0001c40c0, 0xc0000d9938, 0x1, 0x1, 0xc000136ec8, 0x6)
        /home/louis/go/pkg/mod/github.com/99designs/gqlgen@v0.8.1/api/generate.go:37 +0x250
github.com/99designs/gqlgen/cmd.GenerateGraphServer(0xc0001c40c0, 0x9ecc1f, 0x10)
        /home/louis/go/pkg/mod/github.com/99designs/gqlgen@v0.8.1/cmd/init.go:75 +0xad
github.com/99designs/gqlgen/cmd.glob..func2(0xc0001f06e0)
        /home/louis/go/pkg/mod/github.com/99designs/gqlgen@v0.8.1/cmd/init.go:70 +0xc9
github.com/urfave/cli.HandleAction(0x9181c0, 0xa13a50, 0xc0001f06e0, 0xc000114a00, 0x0)
        /home/louis/go/pkg/mod/github.com/urfave/cli@v1.20.0/app.go:492 +0x7c
github.com/urfave/cli.Command.Run(0x9d1f86, 0x4, 0x0, 0x0, 0x0, 0x0, 0x0, 0x9fad8f, 0x1b, 0x0, ...)
        /home/louis/go/pkg/mod/github.com/urfave/cli@v1.20.0/command.go:210 +0x92f
github.com/urfave/cli.(*App).Run(0xc0001b89c0, 0xc00000e080, 0x2, 0x2, 0x0, 0x0)
        /home/louis/go/pkg/mod/github.com/urfave/cli@v1.20.0/app.go:255 +0x69b
github.com/99designs/gqlgen/cmd.Execute()
        /home/louis/go/pkg/mod/github.com/99designs/gqlgen@v0.8.1/cmd/root.go:40 +0x224
main.main()
        /home/louis/go/pkg/mod/github.com/99designs/gqlgen@v0.8.1/main.go:8 +0x20
exit status 2

Minimal graphql.schema and models to reproduce

This one cases the panic:

type Query {
    updatedProfiles: [User!]!
}

type User {
    id: ID!
    about: String!
    karma: Int!
    delay: Int!
}

type Time {    # this is no good
    epoch: Int!
    iso8601: String!
}

And this will work just fine

type Query {
    updatedProfiles: [User!]!
}

type User {
    id: ID!
    about: String!
    karma: Int!
    delay: Int!
}

type Timestamp {    # renamed and everything works fine
    epoch: Int!
    iso8601: String!
}

[mathewbyrne]

I think a panic is probably not the right place to improve the error messaging. Hitting a panic during codegen is usually a case where our validation needs to be improved so that the panic is never hit.

[louis993546]

Wow that's quick! Thanks!

[jufemaiz]

FYI I am currently seeing this on v0.13.

Panics on:

type TimeOfDay {
  hours: Int
  minutes: Int
  seconds: Int
  nanos: Int
}

does not panic on:

type TimeOfDay2 {
  hours: Int
  minutes: Int
  seconds: Int
  nanos: Int
}

or

type TimeOfDayType {
  hours: Int
  minutes: Int
  seconds: Int
  nanos: Int
}