signal_test.go

// Copyright (c) 2022 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPSignalE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

package fx

import (
	"context"
	"os"
	"syscall"
	"testing"

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

func assertUnsentSignalError(
	t *testing.T,
	err error,
	expected *unsentSignalError,
) {
	t.Helper()

	actual := new(unsentSignalError)

	assert.ErrorContains(t, err, "channels are blocked")
	if assert.ErrorAs(t, err, &actual, "is unsentSignalError") {
		assert.Equal(t, expected, actual)
	}
}

func TestSignal(t *testing.T) {
	t.Parallel()
	t.Run("Done", func(t *testing.T) {
		recv := newSignalReceivers()
		a := recv.Done()
		_ = recv.Done() // we never listen on this

		expected := ShutdownSignal{
			Signal: syscall.SIGTERM,
		}

		require.NoError(t, recv.Broadcast(expected), "first broadcast should succeed")

		assertUnsentSignalError(t, recv.Broadcast(expected), &unsentSignalError{
			Signal: expected,
			Total:  2,
			Unsent: 2,
		})

		assert.Equal(t, expected.Signal, <-a)
		assert.Equal(t, expected.Signal, <-recv.Done(), "expect cached signal")
	})

	t.Run("signal notify relayer", func(t *testing.T) {
		t.Parallel()
		t.Run("start and stop", func(t *testing.T) {
			t.Parallel()
			t.Run("timeout", func(t *testing.T) {
				recv := newSignalReceivers()
				ctx, cancel := context.WithCancel(context.Background())
				defer cancel()
				recv.Start(ctx)
				timeoutCtx, cancel := context.WithTimeout(context.Background(), 0)
				defer cancel()
				err := recv.Stop(timeoutCtx)
				require.ErrorIs(t, err, context.DeadlineExceeded)
			})
			t.Run("no error", func(t *testing.T) {
				recv := newSignalReceivers()
				ctx, cancel := context.WithCancel(context.Background())
				defer cancel()
				recv.Start(ctx)
				recv.Start(ctx) // should be a no-op if already running
				require.NoError(t, recv.Stop(ctx))
			})
			t.Run("notify", func(t *testing.T) {
				stub := make(chan os.Signal)
				recv := newSignalReceivers()
				recv.notify = func(ch chan<- os.Signal, _ ...os.Signal) {
					go func() {
						for sig := range stub {
							ch <- sig
						}
					}()
				}
				ctx, cancel := context.WithCancel(context.Background())
				defer cancel()
				recv.Start(ctx)
				stub <- syscall.SIGTERM
				stub <- syscall.SIGTERM
				require.Equal(t, syscall.SIGTERM, <-recv.Done())
				require.Equal(t, syscall.SIGTERM, <-recv.Done())
				sig := <-recv.Wait()
				require.Equal(t, syscall.SIGTERM, sig.Signal)
				require.NoError(t, recv.Stop(ctx))
				close(stub)
			})
		})
	})
}