errors: Improve tests, unify interfaces, wrapping

environs/sshstorage/storage_test.go

 // Copyright 2013 Canonical Ltd.
 // Licensed under the AGPLv3, see LICENCE file for details.
 
 package sshstorage
 
 import (
         "bytes"
         "fmt"
         "io"
         "io/ioutil"
@@ skipping 146 matching lines @@
         for _, name := range []string{"b", filepath.Join("a", "b")} {
                 err = ioutil.WriteFile(filepath.Join(storageDir, name), data, 0644)
                 c.Assert(err, gc.IsNil)
                 r, err := storage.Get(stor, name)
                 c.Assert(err, gc.IsNil)
                 out, err := ioutil.ReadAll(r)
                 c.Assert(err, gc.IsNil)
                 c.Assert(out, gc.DeepEquals, data)
         }
         _, err = storage.Get(stor, "notthere")
-        c.Assert(err, jc.Satisfies, coreerrors.IsNotFoundError)
+        c.Assert(err, jc.Satisfies, coreerrors.IsNotFound)
 }
 
 func (s *storageSuite) TestWriteFailure(c *gc.C) {
         // Invocations:
         //  1: first "install"
         //  2: touch, Put
         //  3: second "install"
         //  4: touch
         var invocations int
         badSshCommand := func(host string, command ...string) *ssh.Cmd {
@@ skipping 213 matching lines @@
 
 func (s *storageSuite) TestPathCharacters(c *gc.C) {
         storageDirBase := c.MkDir()
         storageDir := filepath.Join(storageDirBase, "'")
         tmpdir := filepath.Join(storageDirBase, `"`)
         c.Assert(os.Mkdir(storageDir, 0755), gc.IsNil)
         c.Assert(os.Mkdir(tmpdir, 0755), gc.IsNil)
         _, err := newSSHStorage("example.com", storageDir, tmpdir)
         c.Assert(err, gc.IsNil)
 }