daemon: FakeCommand usage requires reaper.Start() (#247)

internals/daemon/daemon_test.go

@@ -37,6 +37,7 @@ import (
 	"github.com/canonical/pebble/internals/overlord/restart"
 	"github.com/canonical/pebble/internals/overlord/standby"
 	"github.com/canonical/pebble/internals/overlord/state"
+	"github.com/canonical/pebble/internals/reaper"
 	"github.com/canonical/pebble/internals/systemd"
 	"github.com/canonical/pebble/internals/testutil"
 )
@@ -58,6 +59,8 @@ type daemonSuite struct {
 var _ = Suite(&daemonSuite{})
 
 func (s *daemonSuite) SetUpTest(c *C) {
+	err := reaper.Start()
+	c.Assert(err, IsNil)
 	s.pebbleDir = c.MkDir()
 	s.statePath = filepath.Join(s.pebbleDir, ".pebble.state")
 	systemdSdNotify = func(notif string) error {
@@ -71,6 +74,8 @@ func (s *daemonSuite) TearDownTest(c *C) {
 	s.notified = nil
 	s.authorized = false
 	s.err = nil
+	err := reaper.Stop()
+	c.Assert(err, IsNil)
 }
 
 func (s *daemonSuite) newDaemon(c *C) *Daemon {

internals/testutil/exec_test.go

@@ -21,12 +21,24 @@ import (
 	"path/filepath"
 
 	"gopkg.in/check.v1"
+
+	"github.com/canonical/pebble/internals/reaper"
 )
 
 type fakeCommandSuite struct{}
 
 var _ = check.Suite(&fakeCommandSuite{})
 
+func (s *fakeCommandSuite) SetUpSuite(c *check.C) {
+	err := reaper.Start()
+	c.Assert(err, check.IsNil)
+}
+
+func (s *fakeCommandSuite) TearDownSuite(c *check.C) {
+	err := reaper.Stop()
+	c.Assert(err, check.IsNil)
+}
+
 func (s *fakeCommandSuite) TestFakeCommand(c *check.C) {
 	fake := FakeCommand(c, "cmd", "true", false)
 	defer fake.Restore()
@@ -46,6 +58,13 @@ func (s *fakeCommandSuite) TestFakeCommand(c *check.C) {
 	})
 }
 
+func (s *fakeCommandSuite) TestFakeCommandWithReaper(c *check.C) {
+	fake := FakeCommand(c, "cmd", "true", true)
+	defer fake.Restore()
+	err := exec.Command("cmd", "").Run()
+	c.Assert(err, check.IsNil)
+}
+
 func (s *fakeCommandSuite) TestFakeCommandAlso(c *check.C) {
 	fake := FakeCommand(c, "fst", "", false)
 	also := fake.Also("snd", "")