[PATCH 03/11] completion: add test highlighting subpar git switch --track completion

[Jacob Keller <jacob.e.keller@intel.com>]

From: Jacob Keller <jacob.keller@gmail.com>

If git switch is called with --track, it will attempts to DWIM into
creating a local tracking branch that tracks the provided remote branch.
It seems reasonable that, to support this behavior, we should only
complete remote branches in the form "<remote>/<branch>".

Indeed, current completion is not just sub-par, but could almost be
described as entirely useless.

  $git switch --track <TAB>

will only report *local* branch names. Indeed a new test case highlights
this quite well:

  --- expected    2020-04-25 00:25:34.424965326 +0000
  +++ out_sorted  2020-04-25 00:25:34.441965370 +0000
  @@ -1,2 +1,2 @@
  -other/branch-in-other
  -other/master-in-other
  +master
  +matching-branch
  not ok 100 - git switch - with --track, complete only remote branches # TODO known breakage

Understanding exactly what causes this is not that simple.

First we enable DWIM output by default. Then, if "--track",
"--no-track", or "--no-guess" is enabled on the command line, we disable
DWIM. This makes sense, because --track should not include the default
"DWIM" remote branch names.

Following this, there is a check for "--detach". If "--detach" is *not*
present, then we set only_local_ref=y. this is done because we would
like to avoid printing remote references. This immediately seems wrong
because --track should allow completing remote references.

Finally, if only_local_ref is 'y', and the track_opt for DWIM logic is
disabled, we complete only local branches. This occurs because --track
disabled track_opt, and not providing --detach sets only_local_ref to
'y'.

Fixing this correctly is not trivial, so it is left to a follow up
change.

Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
---
 t/t9902-completion.sh | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh
index af4661cbcc73..002223160058 100755
--- a/t/t9902-completion.sh
+++ b/t/t9902-completion.sh
@@ -1271,6 +1271,16 @@ test_expect_success 'git switch - with --detach, complete all references' '
 	EOF
 '
 
+# TODO: Since --track on its own will perform a DWIM to extract the local
+# branch name, we should complete only the remote branches with their remote
+# name.
+test_expect_failure 'git switch - with --track, complete only remote branches' '
+	test_completion "git switch --track " <<-\EOF
+	other/branch-in-other Z
+	other/master-in-other Z
+	EOF
+'
+
 test_expect_success 'git switch - with --no-track, complete only local branch names' '
 	test_completion "git switch --no-track " <<-\EOF
 	master Z
-- 
2.25.2