Reviewers: mp+216540_code.launchpad.net,

Message:
Please take a look.

Description:
various: fix error DeepEquals comparisons

We should not be comparing errors with DeepEquals
in general - they have private fields, and this will
break when using adding trace information with errgo.

https://code.launchpad.net/~rogpeppe/juju-core/559-fix-err-deepequals/+merge/216540

(do not edit description out of merge proposal)


Please review this at https://codereview.appspot.com/89660043/

Affected files (+16, -12 lines):
   A [revision details]
   M state/machine_test.go
   M testing/locking_test.go
   M utils/apt_test.go
   M worker/instancepoller/aggregate_test.go


Index: [revision details]
=== added file '[revision details]'
--- [revision details]	2012-01-01 00:00:00 +0000
+++ [revision details]	2012-01-01 00:00:00 +0000
@@ -0,0 +1,2 @@
+Old revision: tarmac-20140418183250-hzz3f8zpw6ift0az
+New revision: <email address hidden>

Index: state/machine_test.go
=== modified file 'state/machine_test.go'
--- state/machine_test.go	2014-04-18 16:37:28 +0000
+++ state/machine_test.go	2014-04-20 12:41:40 +0000
@@ -137,7 +137,8 @@
  	c.Assert(err, gc.FitsTypeOf, &state.HasContainersError{})
  	c.Assert(err, gc.ErrorMatches, `machine 1 is hosting  
containers "1/lxc/0"`)
  	err1 := s.machine.EnsureDead()
-	c.Assert(err1, gc.DeepEquals, err)
+	c.Assert(err1, gc.FitsTypeOf, &state.HasContainersError{})
+	c.Assert(err1, gc.ErrorMatches, `machine 1 is hosting  
containers "1/lxc/0"`)
  	c.Assert(s.machine.Life(), gc.Equals, state.Alive)
  }

@@ -152,7 +153,8 @@
  	c.Assert(err, gc.FitsTypeOf, &state.HasAssignedUnitsError{})
  	c.Assert(err, gc.ErrorMatches, `machine 1 has unit "wordpress/0"  
assigned`)
  	err1 := s.machine.EnsureDead()
-	c.Assert(err1, gc.DeepEquals, err)
+	c.Assert(err, gc.FitsTypeOf, &state.HasAssignedUnitsError{})
+	c.Assert(err, gc.ErrorMatches, `machine 1 has unit "wordpress/0"  
assigned`)
  	c.Assert(s.machine.Life(), gc.Equals, state.Alive)

  	// Once no unit is assigned, lifecycle can advance.


Index: testing/locking_test.go
=== modified file 'testing/locking_test.go'
--- testing/locking_test.go	2013-08-19 11:20:02 +0000
+++ testing/locking_test.go	2014-04-20 12:40:45 +0000
@@ -4,7 +4,6 @@
  package testing

  import (
-	"errors"
  	"sync"

  	gc "launchpad.net/gocheck"
@@ -29,8 +28,9 @@
  	function := func() {}
  	c.Check(
  		func() { TestLockingFunction(&lock, function) },
-		gc.Panics,
-		errors.New("function did not obey lock"))
+		gc.PanicMatches,
+		"function did not obey lock",
+	)
  }

  func (LockingSuite) TestTestLockingFunctionDetectsFailureToReleaseLock(c  
*gc.C) {
@@ -41,6 +41,7 @@
  	}
  	c.Check(
  		func() { TestLockingFunction(&lock, function) },
-		gc.Panics,
-		errors.New("function did not release lock"))
+		gc.PanicMatches,
+		"function did not release lock",
+	)
  }


Index: utils/apt_test.go
=== modified file 'utils/apt_test.go'
--- utils/apt_test.go	2014-03-21 05:07:45 +0000
+++ utils/apt_test.go	2014-04-20 12:40:45 +0000
@@ -42,10 +42,9 @@
  func (s *AptSuite) TestAptGetError(c *gc.C) {
  	const expected = `E: frobnicator failure detected`
  	cmdError := fmt.Errorf("error")
-	cmdExpectedError := fmt.Errorf("apt-get failed: error")
  	cmdChan := s.HookCommandOutput(&utils.AptCommandOutput, []byte(expected),  
cmdError)
  	err := utils.AptGetInstall("foo")
-	c.Assert(err, gc.DeepEquals, cmdExpectedError)
+	c.Assert(err, gc.ErrorMatches, "apt-get failed: error")
  	cmd := <-cmdChan
  	c.Assert(cmd.Args, gc.DeepEquals, []string{
  		"apt-get", "--option=Dpkg::Options::=--force-confold",
@@ -172,10 +171,9 @@
  func (s *AptSuite) TestConfigProxyError(c *gc.C) {
  	const expected = `E: frobnicator failure detected`
  	cmdError := fmt.Errorf("error")
-	cmdExpectedError := fmt.Errorf("apt-config failed: error")
  	cmdChan := s.HookCommandOutput(&utils.AptCommandOutput, []byte(expected),  
cmdError)
  	out, err := utils.AptConfigProxy()
-	c.Assert(err, gc.DeepEquals, cmdExpectedError)
+	c.Assert(err, gc.ErrorMatches, "apt-config failed: error")
  	cmd := <-cmdChan
  	c.Assert(cmd.Args, gc.DeepEquals, []string{
  		"apt-config", "dump", "Acquire::http::Proxy",


Index: worker/instancepoller/aggregate_test.go
=== modified file 'worker/instancepoller/aggregate_test.go'
--- worker/instancepoller/aggregate_test.go	2014-04-15 18:51:24 +0000
+++ worker/instancepoller/aggregate_test.go	2014-04-20 12:40:45 +0000
@@ -163,7 +163,8 @@
  	aggregator := newAggregator(testGetter)
  	_, err := aggregator.instanceInfo("foo")

-	c.Assert(err, gc.DeepEquals, errors.NotFoundf("instance foo"))
+	c.Assert(err, jc.Satisfies, errors.IsNotFound)
+	c.Assert(err, gc.ErrorMatches, "instance foo not found")
  }

  func (s *aggregateSuite) TestAddressesError(c *gc.C) {