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
package handler
import (
"encoding/json"
"fmt"
"io"
"net/http"
"os"
"strings"
"github.com/ethereum-optimism/optimism/proxyd"
"github.com/gorilla/mux"
"github.com/pkg/errors"
"gopkg.in/yaml.v3"
)
type MethodTemplate struct {
Method string `yaml:"method"`
Block string `yaml:"block"`
Response string `yaml:"response"`
}
type MockedHandler struct {
Overrides []*MethodTemplate
Autoload bool
AutoloadFile string
}
func (mh *MockedHandler) Serve(port int) error {
r := mux.NewRouter()
r.HandleFunc("/", mh.Handler)
http.Handle("/", r)
fmt.Printf("starting server up on :%d serving MockedResponsesFile %s\n", port, mh.AutoloadFile)
err := http.ListenAndServe(fmt.Sprintf(":%d", port), nil)
if errors.Is(err, http.ErrServerClosed) {
fmt.Printf("server closed\n")
} else if err != nil {
fmt.Printf("error starting server: %s\n", err)
return err
}
return nil
}
func (mh *MockedHandler) Handler(w http.ResponseWriter, req *http.Request) {
body, err := io.ReadAll(req.Body)
if err != nil {
fmt.Printf("error reading request: %v\n", err)
}
var template []*MethodTemplate
if mh.Autoload {
template = append(template, mh.LoadFromFile(mh.AutoloadFile)...)
}
if mh.Overrides != nil {
template = append(template, mh.Overrides...)
}
batched := proxyd.IsBatch(body)
var requests []map[string]interface{}
if batched {
err = json.Unmarshal(body, &requests)
if err != nil {
fmt.Printf("error reading request: %v\n", err)
}
} else {
var j map[string]interface{}
err = json.Unmarshal(body, &j)
if err != nil {
fmt.Printf("error reading request: %v\n", err)
}
requests = append(requests, j)
}
var responses []string
for _, r := range requests {
method := r["method"]
block := ""
if method == "eth_getBlockByNumber" {
block = (r["params"].([]interface{})[0]).(string)
}
var selectedResponse string
for _, r := range template {
if r.Method == method && r.Block == block {
selectedResponse = r.Response
}
}
if selectedResponse != "" {
responses = append(responses, selectedResponse)
}
}
resBody := ""
if batched {
resBody = "[" + strings.Join(responses, ",") + "]"
} else {
resBody = responses[0]
}
_, err = fmt.Fprint(w, resBody)
if err != nil {
fmt.Printf("error writing response: %v\n", err)
}
}
func (mh *MockedHandler) LoadFromFile(file string) []*MethodTemplate {
contents, err := os.ReadFile(file)
if err != nil {
fmt.Printf("error reading MockedResponsesFile: %v\n", err)
}
var template []*MethodTemplate
err = yaml.Unmarshal(contents, &template)
if err != nil {
fmt.Printf("error reading MockedResponsesFile: %v\n", err)
}
return template
}
func (mh *MockedHandler) AddOverride(template *MethodTemplate) {
mh.Overrides = append(mh.Overrides, template)
}
func (mh *MockedHandler) ResetOverrides() {
mh.Overrides = make([]*MethodTemplate, 0)
}