Unsafe defer of
.Close method GO-S2307Deferring unsafe method "Close" on type "io.ReadCloser"
160 return err
161 }
162
163 defer res.Body.Close() 164
165 if _, err := io.Copy(w, res.Body); err != nil {
166 return errDeferring unsafe method "Close" on type "io.ReadCloser"
158 if err != nil {
159 return nil, err
160 }
161 defer res.Body.Close()162
163 id := res.Header.Get("Release-Id")
164Deferring unsafe method "Close" on type "io.ReadCloser"
136 if err != nil {
137 return nil, err
138 }
139 defer res.Body.Close()140
141 id := res.Header.Get("Release-Id")
142Deferring unsafe method "Close" on type "io.ReadCloser"
12 if err != nil {
13 return "", err
14 }
15 defer res.Body.Close()16
17 var auth struct {
18 Id stringDeferring unsafe method "Close" on type "io.WriteCloser"
80}
81
82func subscribeLogs(ctx context.Context, w io.WriteCloser, stream string, opts structs.LogsOptions) {
83 defer w.Close() 84
85 ch := make(chan logstorage.Log, 1000)
86
Description
Calling Close() method may return an error, and ignoring the same
might result in a data loss. This is similar to many more Close methods.
For example, on POSIX systems, os.Close uses the close system call underneath,
which may return an EIO:
A previously-uncommitted write(2) encountered an input/output error.
This means that the data written by os.Write hasn't been written to the disk,
which results in a data loss. It is recommended to handle the error returned
by the os.Close call or call os.Sync if available to force the OS to write
the data to the disk.
Bad practice
package main
import (
"fmt"
"os"
)
func foo() error {
f, err := os.Create("/tmp/test.txt")
if err != nil {
return err
}
defer f.Close()
return fmt.Fprint(f, "Hello World")
}
Recommended
package main
import (
"fmt"
"os"
)
func foo() error {
f, err := os.Create("/tmp/test.txt")
if err != nil {
return err
}
err = fmt.Fprint(f, "Hello World")
if err != nil {
return err
}
return f.Close()
}
package main
import (
"fmt"
"os"
)
func foo() error {
f, err := os.Create("/tmp/test.txt")
if err != nil {
return err
}
defer f.Close()
err = fmt.Fprint(f, "Hello World")
if err != nil {
return err
}
return f.Sync()
}