As per https://github.com/graphql-go/graphql/issues/592 if the resolver is made as a thunk, they will be concurrent. To confirm I took the example given at https://github.com/graphql-go/graphql/blob/master/examples/concurrent-resolvers/main.go and changed QueryType to this
// QueryType fields: `concurrentFieldFoo` and `concurrentFieldBar` are resolved
// concurrently because they belong to the same field-level and their `Resolve`
// function returns a function (thunk).
var QueryType = graphql.NewObject(graphql.ObjectConfig{
Name: "Query",
Fields: graphql.Fields{
"concurrentFieldFoo": &graphql.Field{
Type: FieldFooType,
Resolve: func(p graphql.ResolveParams) (interface{}, error) {
var foo = Foo{Name: "Foo's name"}
fmt.Println("concurrentFieldFoo: sleeping for 5 secs...")
time.Sleep(5 * time.Second)
fmt.Println("concurrentFieldFoo: sleeping for 5 secs... done")
return func() (interface{}, error) {
return &foo, nil
}, nil
},
},
"concurrentFieldBar": &graphql.Field{
Type: FieldBarType,
Resolve: func(p graphql.ResolveParams) (interface{}, error) {
var foo = Bar{Name: "Bar's name"}
fmt.Println("concurrentFieldBar: sleeping for 5 secs...")
time.Sleep(5 * time.Second)
fmt.Println("concurrentFieldFoo: sleeping for 5 secs... done")
return func() (interface{}, error) {
return &foo, nil
}, nil
},
},
},
})
concurrentFieldFoo and concurrentFieldBar have the same logic - deviating from the sample code where there was a go routine that was created to send the data in later - where both the resolvers sleep for 5 seconds.
In my output, I was expecting to see, the following:
concurrentFieldFoo: sleeping for 5 secs...
concurrentFieldBar: sleeping for 5 secs...
concurrentFieldFoo: sleeping for 5 secs... done
concurrentFieldFoo: sleeping for 5 secs... done
But I am seeing this:
concurrent-resolvers git:(master) ✗ go run main.go
concurrentFieldFoo: sleeping for 5 secs...
concurrentFieldFoo: sleeping for 5 secs... done
concurrentFieldBar: sleeping for 5 secs...
concurrentFieldFoo: sleeping for 5 secs... done
{"data":{"concurrentFieldBar":{"name":"Bar's name"},"concurrentFieldFoo":{"name":"Foo's name"}}}%
This is not what I understood from https://github.com/graphql-go/graphql/pull/388 .
What am I missing here?
Full source attached here
package main
import (
"encoding/json"
"fmt"
"log"
"time"
"github.com/graphql-go/graphql"
)
type Foo struct {
Name string
}
var FieldFooType = graphql.NewObject(graphql.ObjectConfig{
Name: "Foo",
Fields: graphql.Fields{
"name": &graphql.Field{Type: graphql.String},
},
})
type Bar struct {
Name string
}
var FieldBarType = graphql.NewObject(graphql.ObjectConfig{
Name: "Bar",
Fields: graphql.Fields{
"name": &graphql.Field{Type: graphql.String},
},
})
// QueryType fields: `concurrentFieldFoo` and `concurrentFieldBar` are resolved
// concurrently because they belong to the same field-level and their `Resolve`
// function returns a function (thunk).
var QueryType = graphql.NewObject(graphql.ObjectConfig{
Name: "Query",
Fields: graphql.Fields{
"concurrentFieldFoo": &graphql.Field{
Type: FieldFooType,
Resolve: func(p graphql.ResolveParams) (interface{}, error) {
var foo = Foo{Name: "Foo's name"}
fmt.Println("concurrentFieldFoo: sleeping for 5 secs...")
time.Sleep(5 * time.Second)
fmt.Println("concurrentFieldFoo: sleeping for 5 secs... done")
return func() (interface{}, error) {
return &foo, nil
}, nil
},
},
"concurrentFieldBar": &graphql.Field{
Type: FieldBarType,
Resolve: func(p graphql.ResolveParams) (interface{}, error) {
var foo = Bar{Name: "Bar's name"}
fmt.Println("concurrentFieldBar: sleeping for 5 secs...")
time.Sleep(5 * time.Second)
fmt.Println("concurrentFieldFoo: sleeping for 5 secs... done")
return func() (interface{}, error) {
return &foo, nil
}, nil
},
},
},
})
func main() {
schema, err := graphql.NewSchema(graphql.SchemaConfig{
Query: QueryType,
})
if err != nil {
log.Fatal(err)
}
query := `
query {
concurrentFieldFoo {
name
}
concurrentFieldBar {
name
}
}
`
result := graphql.Do(graphql.Params{
RequestString: query,
Schema: schema,
})
b, err := json.Marshal(result)
if err != nil {
log.Fatal(err)
}
fmt.Printf("%s", b)
/*
{
"data": {
"concurrentFieldBar": {
"name": "Bar's name"
},
"concurrentFieldFoo": {
"name": "Foo's name"
}
}
}
*/
}
