1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
|
package graphql_test
import (
"context"
"encoding/json"
"fmt"
"os"
"github.com/graph-gophers/graphql-go"
)
type product struct {
ID graphql.ID
Name string
}
type custErrResolver struct {
products map[graphql.ID]*product
}
func (r *custErrResolver) Product(ctx context.Context, args struct{ ID graphql.ID }) (*productResolver, error) {
if p := r.products[args.ID]; p != nil {
return &productResolver{p: p}, nil
}
traceID := "your-trace-id-here" // get trace ID from ctx
return nil, &productNotFoundError{Code: "NotFound", Message: "Product not found", TraceID: traceID}
}
type productResolver struct {
p *product
}
func (r *productResolver) ID() graphql.ID {
return r.p.ID
}
func (r *productResolver) Name() string {
return r.p.Name
}
type productNotFoundError struct {
Code string `json:"code"`
Message string `json:"message"`
TraceID string `json:"traceId"`
}
func (e productNotFoundError) Error() string {
return fmt.Sprintf("error [%s]: %s.", e.Code, e.Message)
}
// Extensions provides additional error context according to the spec https://spec.graphql.org/October2021/#sel-GAPHRPZCAACCBx6b.
func (e productNotFoundError) Extensions() map[string]interface{} {
return map[string]interface{}{
"code": e.Code,
"message": e.Message,
"traceId": e.TraceID,
}
}
// Example_customErrors demonstrates the use of custom errors and error extensions.
func Example_customErrors() {
products := []*product{
{ID: "1000", Name: "Product1"},
{ID: "1001", Name: "Product2"},
}
resolver := &custErrResolver{
products: map[graphql.ID]*product{},
}
for _, p := range products {
resolver.products[p.ID] = p
}
s := `
schema {
query: Query
}
type Query {
product(id: ID!): Product!
}
type Product {
id: ID!
name: String!
}
`
schema := graphql.MustParseSchema(s, resolver)
query := `
query {
product(id: "1007") {
id
name
}
}
`
res := schema.Exec(context.Background(), query, "", nil)
enc := json.NewEncoder(os.Stdout)
enc.SetIndent("", " ")
err := enc.Encode(res)
if err != nil {
panic(err)
}
// output:
// {
// "errors": [
// {
// "message": "error [NotFound]: Product not found.",
// "path": [
// "product"
// ],
// "extensions": {
// "code": "NotFound",
// "message": "Product not found",
// "traceId": "your-trace-id-here"
// }
// }
// ],
// "data": null
// }
}
|
