statecmd: don't use juju.Conn unnecessarily

state/machine_test.go

 package state_test
 
 import (
         . "launchpad.net/gocheck"
         "launchpad.net/juju-core/state"
         "launchpad.net/juju-core/version"
         "sort"
         "time"
 )
 
@@ skipping 62 matching lines @@
         err = s.machine.EnsureDead()
         c.Assert(err, IsNil)
         err = s.machine.Remove()
         c.Assert(err, IsNil)
         err = s.machine.Refresh()
         c.Assert(state.IsNotFound(err), Equals, true)
         err = s.machine.Remove()
         c.Assert(err, IsNil)
 }
 
+func (s *MachineSuite) TestDestroyMachines(c *C) {
+        m0 := s.machine
+        m1, err := s.State.AddMachine("series", state.JobManageEnviron)
+        c.Assert(err, IsNil)
+        m2, err := s.State.AddMachine("series", state.JobHostUnits)
+        c.Assert(err, IsNil)
+
+        sch := s.AddTestingCharm(c, "wordpress")
+        wordpress, err := s.State.AddService("wordpress", sch)
+        c.Assert(err, IsNil)
+        u, err := wordpress.AddUnit()
+        c.Assert(err, IsNil)
+        err = u.AssignToMachine(m0)
+        c.Assert(err, IsNil)
+
+        err = s.State.DestroyMachines("0", "1", "2")
+        c.Assert(err, ErrorMatches, `some machines were not destroyed: machine 0 has unit "wordpress/0" assigned; machine 1 is required by the environment`)
+        assertLife := func(m *state.Machine, life state.Life) {
+                err := m.Refresh()
+                c.Assert(err, IsNil)
+                c.Assert(m.Life(), Equals, life)
+        }
+        assertLife(m0, state.Alive)
+        assertLife(m1, state.Alive)
+        assertLife(m2, state.Dying)
+
+        err = u.UnassignFromMachine()
+        c.Assert(err, IsNil)
+        err = s.State.DestroyMachines("0", "1", "2")
+        c.Assert(err, ErrorMatches, `some machines were not destroyed: machine 1 is required by the environment`)
+        assertLife(m0, state.Dying)
+        assertLife(m1, state.Alive)
+        assertLife(m2, state.Dying)
+}
+
 func (s *MachineSuite) TestMachineSetAgentAlive(c *C) {
         alive, err := s.machine.AgentAlive()
         c.Assert(err, IsNil)
         c.Assert(alive, Equals, false)
 
         pinger, err := s.machine.SetAgentAlive()
         c.Assert(err, IsNil)
         c.Assert(pinger, NotNil)
         defer pinger.Stop()
 
@@ skipping 535 matching lines @@
         err := s.machine.SetAnnotations(annotations)
         c.Assert(err, IsNil)
         err = s.machine.EnsureDead()
         c.Assert(err, IsNil)
         err = s.machine.Remove()
         c.Assert(err, IsNil)
         ann, err := s.machine.Annotations()
         c.Assert(err, IsNil)
         c.Assert(ann, DeepEquals, make(map[string]string))
 }