[PATCH v4 2/2] reset: add tests for git reset -

[Sundararajan R <dyoucme@gmail.com>]

The failure case which occurs on teaching git the '-' shorthand
is when there exists no branch pointed to by '@{-1}'. In this case, if there 
is a file named - in the working tree, the user can be unambiguously 
assumed to be referring to it while issuing this command.

The ambiguous case occurs when the @{-1} branch exists and file named '-' also
exists in the working tree. This are also treated as a failure case but here 
the user is given advice as to how he can proceed.

Another potentially tricky case is when the file '@{-1}' exists. In this case,
the command should succeed as the user hasn't mentioned the file '@{-1}' and can
be safely assumed to be referring to the @{-1} branch.

Add tests to check the handling of these cases.
Also add a test to verify that reset - behaves like reset @{-1} when none
of the above cases are true.

Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Helped-by: Matthieu Moy <Matthieu.Moy@grenoble-inp.fr>
Signed-off-by: Sundararajan R <dyoucme@gmail.com>
---
Have made the edits suggested by Matthew and Kevin.

 t/t7102-reset.sh | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)

diff --git a/t/t7102-reset.sh b/t/t7102-reset.sh
index 98bcfe2..a605c32 100755
--- a/t/t7102-reset.sh
+++ b/t/t7102-reset.sh
@@ -568,4 +568,78 @@ test_expect_success 'reset --mixed sets up work tree' '
 	test_cmp expect actual
 '
 
+test_expect_success 'reset - with no @{-1} branch should fail' '
+	test_when_finished rm -rf new &&
+	git init new &&
+	(
+		cd new &&
+		test_must_fail git reset - 2>../actual
+	) && 
+	test_i18ngrep "bad flag" actual 
+'
+
+test_expect_success 'reset - with no @{-1} branch and file named - should succeed' '
+	test_when_finished rm -rf new &&
+	git init new &&
+	(
+		cd new &&
+		echo "Hello" >- &&
+		git add - &&
+		git reset - >../actual 
+	) &&
+	test_must_be_empty actual
+'
+
+test_expect_success 'reset - with @{-1} branch and file named - should fail' '
+	test_when_finished rm -rf new &&
+	git init new &&
+	(
+		cd new && 
+		echo "Hello" >- &&
+		git add - &&
+		git commit -m "first_commit" &&
+		git checkout -b new_branch &&
+		>- &&
+		git add - &&
+		test_must_fail git reset - 2>../actual 
+	) &&
+	test_i18ngrep "ambiguous argument" actual 
+'
+
+test_expect_success 'reset - with @{-1} branch and file named @{-1} should succeed' '
+	test_when_finished rm -rf new &&
+	git init new &&
+	(
+		cd new && 
+		echo "Hello" >@{-1} &&
+		git add @{-1} &&
+		git commit -m "first_commit" &&
+		git checkout -b new_branch &&
+		>@{-1} &&
+		git add @{-1} &&
+		git reset - >../actual 
+	) &&
+	test_i18ngrep "Unstaged" actual 
+'
+
+test_expect_success 'reset - with @{-1} branch and no file named - should succeed' '
+	test_when_finished rm -rf new &&
+	git init new &&
+	(
+		cd new &&
+		echo "Hey" >new_file &&
+		git add new_file &&
+		git commit -m "first_commit" &&
+		git checkout -b new_branch &&
+		>new_file &&
+		git add new_file &&
+		git reset - &&
+		git status -uno --porcelain >actual &&
+		git add new_file &&
+		git reset @{-1} &&
+		git status -uno --porcelain >expected &&
+		test_cmp actual expected 
+	)
+'
+
 test_done
-- 
2.1.0