Usage of both value and pointer receivers GO-W1029
Anti-pattern
Major
4 months ago
—
4 months old
Type "SecurityData" has both value and pointer receivers
20 return ""
21}
22
23func (data *SecurityData) Fetch() {24 data.Dns = DnsServers()
25 data.FirewallEnabled = FirewallState()
26 data.FirewallStealth = FirewallStealthState()Type "SecurityData" has both value and pointer receivers
13 return &SecurityData{}
14}
15
16func (data SecurityData) DnsAt(idx int) string {17 if len(data.Dns) > idx {
18 return data.Dns[idx]
19 }Type "AlertState" has both value and pointer receivers
46}
47
48// UnmarshalJSON unmashals a quoted json string to the enum value
49func (s *AlertState) UnmarshalJSON(b []byte) error { 50 var j string
51 err := json.Unmarshal(b, &j)
52 if err != nil {Type "AlertState" has both value and pointer receivers
38}
39
40// MarshalJSON marshals the enum as a quoted json string
41func (s AlertState) MarshalJSON() ([]byte, error) { 42 buffer := bytes.NewBufferString(`"`)
43 buffer.WriteString(toString[s])
44 buffer.WriteString(`"`)
Description
(Go's FAQ)[https://go.dev/doc/faq#methodsonvaluesorpointers] recommends that method receivers should be consistent. If some of the methods of the type must have pointer receivers, the rest should too, so the method set is consistent regardless of how the type is used. This is because value and pointer receivers have different method sets.
Bad practice
package main
type foo struct {
a int
}
func (f foo) a() {}
func (f *foo) b() {
f.a = 10
}
Recommended
package main
type foo struct {
a int
}
func (f *foo) a() {}
func (f *foo) b() {
f.a = 10
}