forked from 99designs/gqlgen
/
client.go
153 lines (125 loc) · 3.32 KB
/
client.go
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
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
// client is used internally for testing. See readme for alternatives
package client
import (
"bytes"
"encoding/json"
"fmt"
"io/ioutil"
"net/http"
"github.com/mitchellh/mapstructure"
)
// Client for graphql requests
type Client struct {
url string
client *http.Client
}
// New creates a graphql client
func New(url string, client ...*http.Client) *Client {
p := &Client{
url: url,
}
if len(client) > 0 {
p.client = client[0]
} else {
p.client = http.DefaultClient
}
return p
}
type Request struct {
Query string `json:"query"`
Variables map[string]interface{} `json:"variables,omitempty"`
OperationName string `json:"operationName,omitempty"`
}
type Option func(r *Request)
func Var(name string, value interface{}) Option {
return func(r *Request) {
if r.Variables == nil {
r.Variables = map[string]interface{}{}
}
r.Variables[name] = value
}
}
func Operation(name string) Option {
return func(r *Request) {
r.OperationName = name
}
}
func (p *Client) MustPost(query string, response interface{}, options ...Option) {
if err := p.Post(query, response, options...); err != nil {
panic(err)
}
}
func (p *Client) mkRequest(query string, options ...Option) Request {
r := Request{
Query: query,
}
for _, option := range options {
option(&r)
}
return r
}
type ResponseData struct {
Data interface{}
Errors json.RawMessage
Extensions map[string]interface{}
}
func (p *Client) Post(query string, response interface{}, options ...Option) (resperr error) {
respDataRaw, resperr := p.RawPost(query, options...)
if resperr != nil {
return resperr
}
// we want to unpack even if there is an error, so we can see partial responses
unpackErr := unpack(respDataRaw.Data, response)
if respDataRaw.Errors != nil {
return RawJsonError{respDataRaw.Errors}
}
return unpackErr
}
func (p *Client) RawPost(query string, options ...Option) (*ResponseData, error) {
r := p.mkRequest(query, options...)
requestBody, err := json.Marshal(r)
if err != nil {
return nil, fmt.Errorf("encode: %s", err.Error())
}
rawResponse, err := p.client.Post(p.url, "application/json", bytes.NewBuffer(requestBody))
if err != nil {
return nil, fmt.Errorf("post: %s", err.Error())
}
defer func() {
_ = rawResponse.Body.Close()
}()
if rawResponse.StatusCode >= http.StatusBadRequest {
responseBody, _ := ioutil.ReadAll(rawResponse.Body)
return nil, fmt.Errorf("http %d: %s", rawResponse.StatusCode, responseBody)
}
responseBody, err := ioutil.ReadAll(rawResponse.Body)
if err != nil {
return nil, fmt.Errorf("read: %s", err.Error())
}
// decode it into map string first, let mapstructure do the final decode
// because it can be much stricter about unknown fields.
respDataRaw := &ResponseData{}
err = json.Unmarshal(responseBody, &respDataRaw)
if err != nil {
return nil, fmt.Errorf("decode: %s", err.Error())
}
return respDataRaw, nil
}
type RawJsonError struct {
json.RawMessage
}
func (r RawJsonError) Error() string {
return string(r.RawMessage)
}
func unpack(data interface{}, into interface{}) error {
d, err := mapstructure.NewDecoder(&mapstructure.DecoderConfig{
Result: into,
TagName: "json",
ErrorUnused: true,
ZeroFields: true,
})
if err != nil {
return fmt.Errorf("mapstructure: %s", err.Error())
}
return d.Decode(data)
}