cmd: No longer panic if cwd is deleted

cmd/juju/cmd_test.go

 // Copyright 2012, 2013 Canonical Ltd.
 // Licensed under the AGPLv3, see LICENCE file for details.
 
 package main
 
 import (
         "io"
         "io/ioutil"
         "os"
         "reflect"
@@ skipping 105 matching lines @@
                 assertConnName(c, com, "walthamstow")
 
                 com, args = cmdFunc()
                 if _, ok := com.(*StatusCommand); !ok {
                         testInit(c, com, append(args, "hotdog"), "unrecognized args.*")
                 }
         }
 }
 
 func nullContext() *cmd.Context {
-        ctx := cmd.DefaultContext()
+        ctx, _ := cmd.DefaultContext()

[dimitern, 2014/03/21 16:46:00]

It's bad to ignore errors like this, how about:

ctx, err := cmd.DefaultContext()
c.Assert(err, gc.IsNil)

and take c *gc.C as an argument.

         ctx.Stdin = io.LimitReader(nil, 0)
         ctx.Stdout = ioutil.Discard
         ctx.Stderr = ioutil.Discard
         return ctx
 }
 
 func runCommand(ctx *cmd.Context, com cmd.Command, args ...string) (opc chan dummy.Operation, errc chan error) {
         if ctx == nil {
                 panic("ctx == nil")
         }
@@ skipping 232 matching lines @@
 }
 
 func (*CmdSuite) TestDestroyUnitCommandInit(c *gc.C) {
         // missing args
         _, err := initDestroyUnitCommand()
         c.Assert(err, gc.ErrorMatches, "no units specified")
         // not a unit
         _, err = initDestroyUnitCommand("seven/nine")
         c.Assert(err, gc.ErrorMatches, `invalid unit name "seven/nine"`)
 }