96 lines
3.1 KiB
Markdown
96 lines
3.1 KiB
Markdown
|
# noctx
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
`noctx` finds sending http request without context.Context.
|
||
|
|
|
||
|
|
You should use `noctx` if sending http request in your library.
|
||
|
|
Passing `context.Context` enables library user to cancel http request, getting trace information and so on.
|
||
|
|
|
||
|
|
## Install
|
||
|
|
|
||
|
|
```sh
|
||
|
|
$ go get -u github.com/sonatard/noctx/cmd/noctx
|
||
|
|
```
|
||
|
|
|
||
|
|
## Usage
|
||
|
|
|
||
|
|
```sh
|
||
|
|
$ go vet -vettool=`which noctx` main.go
|
||
|
|
./main.go:6:11: net/http.Get must not be called
|
||
|
|
```
|
||
|
|
|
||
|
|
## Detection rules
|
||
|
|
- Executing following functions
|
||
|
|
- `net/http.Get`
|
||
|
|
- `net/http.Head`
|
||
|
|
- `net/http.Post`
|
||
|
|
- `net/http.PostForm`
|
||
|
|
- `(*net/http.Client).Get`
|
||
|
|
- `(*net/http.Client).Head`
|
||
|
|
- `(*net/http.Client).Post`
|
||
|
|
- `(*net/http.Client).PostForm`
|
||
|
|
- `http.Request` returned by `http.NewRequest` function and passes it to other function.
|
||
|
|
|
||
|
|
## How to fix
|
||
|
|
- Send http request using `(*http.Client).Do(*http.Request)` method.
|
||
|
|
- In Go 1.13 and later, use `http.NewRequestWithContext` function instead of using `http.NewRequest` function.
|
||
|
|
- In Go 1.12 and earlier, call `(http.Request).WithContext(ctx)` after `http.NewRequest`.
|
||
|
|
|
||
|
|
`(http.Request).WithContext(ctx)` has a disadvantage of performance because it returns a copy of `http.Request`. Use `http.NewRequestWithContext` function if you only support Go1.13 or later.
|
||
|
|
|
||
|
|
## Sample Code
|
||
|
|
|
||
|
|
```go
|
||
|
|
package main
|
||
|
|
|
||
|
|
import (
|
||
|
|
"context"
|
||
|
|
"net/http"
|
||
|
|
)
|
||
|
|
|
||
|
|
func main() {
|
||
|
|
const url = "http://example.com"
|
||
|
|
http.Get(url) // want `net/http\.Get must not be called`
|
||
|
|
http.Head(url) // want `net/http\.Head must not be called`
|
||
|
|
http.Post(url, "", nil) // want `net/http\.Post must not be called`
|
||
|
|
http.PostForm(url, nil) // want `net/http\.PostForm must not be called`
|
||
|
|
|
||
|
|
cli := &http.Client{}
|
||
|
|
cli.Get(url) // want `\(\*net/http\.Client\)\.Get must not be called`
|
||
|
|
cli.Head(url) // want `\(\*net/http\.Client\)\.Head must not be called`
|
||
|
|
cli.Post(url, "", nil) // want `\(\*net/http\.Client\)\.Post must not be called`
|
||
|
|
cli.PostForm(url, nil) // want `\(\*net/http\.Client\)\.PostForm must not be called`
|
||
|
|
|
||
|
|
req, _ := http.NewRequest(http.MethodPost, url, nil) // want `should rewrite http.NewRequestWithContext or add \(\*Request\).WithContext`
|
||
|
|
cli.Do(req)
|
||
|
|
|
||
|
|
ctx := context.Background()
|
||
|
|
req2, _ := http.NewRequestWithContext(ctx, http.MethodPost, url, nil) // OK
|
||
|
|
cli.Do(req2)
|
||
|
|
|
||
|
|
req3, _ := http.NewRequest(http.MethodPost, url, nil) // OK
|
||
|
|
req3 = req3.WithContext(ctx)
|
||
|
|
cli.Do(req3)
|
||
|
|
|
||
|
|
f2 := func(req *http.Request, ctx context.Context) *http.Request {
|
||
|
|
return req
|
||
|
|
}
|
||
|
|
req4, _ := http.NewRequest(http.MethodPost, url, nil) // want `should rewrite http.NewRequestWithContext or add \(\*Request\).WithContext`
|
||
|
|
req4 = f2(req4, ctx)
|
||
|
|
cli.Do(req4)
|
||
|
|
|
||
|
|
req5, _ := func() (*http.Request, error) {
|
||
|
|
return http.NewRequest(http.MethodPost, url, nil) // want `should rewrite http.NewRequestWithContext or add \(\*Request\).WithContext`
|
||
|
|
}()
|
||
|
|
cli.Do(req5)
|
||
|
|
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
## Reference
|
||
|
|
- [net/http - NewRequest](https://golang.org/pkg/net/http/#NewRequest)
|
||
|
|
- [net/http - NewRequestWithContext](https://golang.org/pkg/net/http/#NewRequestWithContext)
|
||
|
|
- [net/http - Request.WithContext](https://golang.org/pkg/net/http/#Request.WithContext)
|
||
|
|
|