bodyclose: possible false positive

[juan-carvajal]

Hey, I got a response body must be closed (bodyclose) inside a handler using http.NewResponseController. I tried closing the body in a defer at the beginning of the handler but the error still shows. In any case, the location that the linter is marking does not seem appropriate, is this a bug?

response body must be closed (bodyclose)
                rc := http.NewResponseController(w)
                                                ^

[juan-carvajal]

This is the full handler code:

type handlerChecker func(t *testing.T, r *http.Request)

func dummySSEHandler(t *testing.T, checks ...handlerChecker) http.Handler {
	t.Helper()
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		for _, check := range checks {
			check(t, r)
		}

		w.Header().Set("Content-Type", "text/event-stream")
		w.Header().Set("Cache-Control", "no-cache")
		w.Header().Set("Connection", "keep-alive")
		w.WriteHeader(http.StatusOK)

		//nolint:bodyclose
		rc := http.NewResponseController(w)
		readFile, err := os.Open("./testdata/streaming-input.txt")
		require.NoError(t, err)

		defer readFile.Close()

		fileScanner := bufio.NewScanner(readFile)

		fileScanner.Split(bufio.ScanLines)

		for fileScanner.Scan() {
			_, err := w.Write([]byte(fileScanner.Text() + "\n\n"))
			require.NoError(t, err)
			err = rc.Flush()
			require.NoError(t, err)
		}
	})
}

[ldez]

The repo of the linter is here: https://github.com/timakin/bodyclose

[ldez]

foo_test.go

package sandbox

import (
	"bufio"
	"net/http"
	"os"
	"testing"

	"github.com/stretchr/testify/require"
)

type handlerChecker func(t *testing.T, r *http.Request)

func dummySSEHandler(t *testing.T, checks ...handlerChecker) http.Handler {
	t.Helper()

	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		for _, check := range checks {
			check(t, r)
		}

		w.Header().Set("Content-Type", "text/event-stream")
		w.Header().Set("Cache-Control", "no-cache")
		w.Header().Set("Connection", "keep-alive")
		w.WriteHeader(http.StatusOK)

		rc := http.NewResponseController(w)

		readFile, err := os.Open("./testdata/streaming-input.txt")
		require.NoError(t, err)

		defer readFile.Close()

		fileScanner := bufio.NewScanner(readFile)

		fileScanner.Split(bufio.ScanLines)

		for fileScanner.Scan() {
			_, err := w.Write([]byte(fileScanner.Text() + "\n\n"))
			require.NoError(t, err)
			err = rc.Flush()
			require.NoError(t, err)
		}
	})
}

.golangci.yml

linters:
  disable-all: true
  enable:
    - bodyclose

output:
  show-stats: true

$ golangci-lint run
0 issues.

[ldez]

foo_test.go

package sandbox

import (
	"bufio"
	"net/http"
	"os"
	"testing"

	"github.com/stretchr/testify/require"
)

type handlerChecker func(t *testing.T, r *http.Request)

func dummySSEHandler(t *testing.T, checks ...handlerChecker) http.Handler {
	t.Helper()

	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		for _, check := range checks {
			check(t, r)
		}

		w.Header().Set("Content-Type", "text/event-stream")
		w.Header().Set("Cache-Control", "no-cache")
		w.Header().Set("Connection", "keep-alive")
		w.WriteHeader(http.StatusOK)

		//nolint:bodyclose
		rc := http.NewResponseController(w)

		readFile, err := os.Open("./testdata/streaming-input.txt")
		require.NoError(t, err)

		defer readFile.Close()

		fileScanner := bufio.NewScanner(readFile)

		fileScanner.Split(bufio.ScanLines)

		for fileScanner.Scan() {
			_, err := w.Write([]byte(fileScanner.Text() + "\n\n"))
			require.NoError(t, err)
			err = rc.Flush()
			require.NoError(t, err)
		}
	})
}

.golangci.yml

linters:
  disable-all: true
  enable:
    - bodyclose
    - nolintlint

output:
  show-stats: true

$ golangci-lint run
foo_test.go:27:3: directive `//nolint:bodyclose` is unused for linter "bodyclose" (nolintlint)
                //nolint:bodyclose
                ^
1 issues:
* nolintlint: 1

[juan-carvajal]

Hey @ldez , thanks for the answer, I guess this is maybe a false positive related to the version? I can see you are not able to reproduce the issue. I am using v1.56.1

[ldez]

You should update to latest version: v1.63.4