[Bug]: WithAfterReadyCommand incorrect iterator scope

[itsnotapt]

Testcontainers version

0.32.0

Using the latest Testcontainers version?

Yes

Host OS

MacOS

Host arch

ARM64

Go version

1.22.4

Docker version

Server: Docker Desktop 4.22.1 (118664)
 Engine:
  Version:          24.0.5
  API version:      1.43 (minimum version 1.12)
  Go version:       go1.20.6
  Git commit:       a61e2b4
  Built:            Fri Jul 21 20:35:38 2023
  OS/Arch:          linux/arm64
  Experimental:     false
 containerd:
  Version:          1.6.21
  GitCommit:        3dce8eb055cbb6872793272b4f20ed16117344f8
 runc:
  Version:          1.1.7
  GitCommit:        v1.1.7-0-g860f061
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

Docker info

Server:
 Containers: 10
  Running: 9
  Paused: 0
  Stopped: 1
 Images: 24
 Server Version: 24.0.5
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Using metacopy: false
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 3dce8eb055cbb6872793272b4f20ed16117344f8
 runc version: v1.1.7-0-g860f061
 init version: de40ad0
 Security Options:
  seccomp
   Profile: unconfined
  cgroupns
 Kernel Version: 5.15.49-linuxkit-pr
 Operating System: Docker Desktop
 OSType: linux
 Architecture: aarch64
 CPUs: 5
 Total Memory: 7.667GiB
 Name: docker-desktop
 ID: 8e7dabbb-25ee-4f34-9fe5-2df589d4f8b3
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 HTTP Proxy: http.docker.internal:3128
 HTTPS Proxy: http.docker.internal:3128
 No Proxy: hubproxy.docker.internal
 Experimental: false
 Insecure Registries:
  hubproxy.docker.internal:5555
  127.0.0.0/8
 Live Restore Enabled: false

What happened?

The for loop for generating the functions associated with WithAfterReadyCommand is referencing the wrong scope.

Consider this test:

func TestWithAfterReadyCommand(t *testing.T) {
	req := testcontainers.GenericContainerRequest{
		ContainerRequest: testcontainers.ContainerRequest{
			Image:      "alpine",
			Entrypoint: []string{"tail", "-f", "/dev/null"},
		},
		Started: true,
	}

	testExec := []testcontainers.Executable{
		testcontainers.NewRawCommand([]string{"touch", "/tmp/.testcontainers-1"}),
		testcontainers.NewRawCommand([]string{"touch", "/tmp/.testcontainers-2"}),
		testcontainers.NewRawCommand([]string{"touch", "/tmp/.testcontainers-3"}),
	}

	err := testcontainers.WithAfterReadyCommand(testExec...)(&req)
	require.NoError(t, err)

	c, err := testcontainers.GenericContainer(context.Background(), req)
	require.NoError(t, err)
	defer func() {
		err = c.Terminate(context.Background())
		require.NoError(t, err)
	}()

	for i := 1; i <= 3; i++ {
		_, reader, err := c.Exec(context.Background(), []string{"ls", fmt.Sprintf("/tmp/.testcontainers-%d", i)}, exec.Multiplexed())
		require.NoError(t, err)

		content, err := io.ReadAll(reader)
		require.NoError(t, err)
		assert.Equal(t, fmt.Sprintf("/tmp/.testcontainers-%d\n", i), string(content))
	}
}

This will fail with go 1.21. However, if you update to go 1.22 or use the env var GOEXPERIMENT=loopvar the test will pass.

Simple fix is to update the scope for exec at https://github.com/testcontainers/testcontainers-go/blob/70b90cce99b42b5c5e64646e9fd30471c85e0d9d/options.go#L275

exec := exec
execFn := func(ctx context.Context, c Container) error {
	_, _, err := c.Exec(ctx, exec.AsCommand(), exec.Options()...)
	return err
}

Relevant log output

No response

Additional information

No response