t7611: replace test -f with test_path_is* helpers

Replace `test -f` and `test ! -f` with `test_path_is_file` and
`test_path_is_missing` for better debuggability.

While `test -f` ensures that the file exists and is a regular file,
`test_path_is_file` provides clearer error messages on failure.

On the other hand, `test ! -f` checks either the absence of a regular
file or the presence of any other filesystem object, but looking at
them in the test individually, all of them should've said `test ! -e`,
i.e. "there shouldn't be anything at given path on filesystem."

Replace these cases with `test_path_is_missing` for better
debuggability.

Helped-by: karthik nayak <karthik.188@gmail.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Meet Soni <meetsoni3017@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/t/t7611-merge-abort.sh b/t/t7611-merge-abort.sh
index d6975ca..1a25148 100755
--- a/t/t7611-merge-abort.sh
+++ b/t/t7611-merge-abort.sh
@@ -54,13 +54,13 @@
 '
 
 test_expect_success 'fails without MERGE_HEAD (unstarted merge): .git/MERGE_HEAD sanity' '
-	test ! -f .git/MERGE_HEAD &&
+	test_path_is_missing .git/MERGE_HEAD &&
 	test "$pre_merge_head" = "$(git rev-parse HEAD)"
 '
 
 test_expect_success 'fails without MERGE_HEAD (completed merge)' '
 	git merge clean_branch &&
-	test ! -f .git/MERGE_HEAD &&
+	test_path_is_missing .git/MERGE_HEAD &&
 	# Merge successfully completed
 	post_merge_head="$(git rev-parse HEAD)" &&
 	test_must_fail git merge --abort 2>output &&
@@ -68,7 +68,7 @@
 '
 
 test_expect_success 'fails without MERGE_HEAD (completed merge): .git/MERGE_HEAD sanity' '
-	test ! -f .git/MERGE_HEAD &&
+	test_path_is_missing .git/MERGE_HEAD &&
 	test "$post_merge_head" = "$(git rev-parse HEAD)"
 '
 
@@ -79,10 +79,10 @@
 test_expect_success 'Abort after --no-commit' '
 	# Redo merge, but stop before creating merge commit
 	git merge --no-commit clean_branch &&
-	test -f .git/MERGE_HEAD &&
+	test_path_is_file .git/MERGE_HEAD &&
 	# Abort non-conflicting merge
 	git merge --abort &&
-	test ! -f .git/MERGE_HEAD &&
+	test_path_is_missing .git/MERGE_HEAD &&
 	test "$pre_merge_head" = "$(git rev-parse HEAD)" &&
 	test -z "$(git diff)" &&
 	test -z "$(git diff --staged)"
@@ -91,10 +91,10 @@
 test_expect_success 'Abort after conflicts' '
 	# Create conflicting merge
 	test_must_fail git merge conflict_branch &&
-	test -f .git/MERGE_HEAD &&
+	test_path_is_file .git/MERGE_HEAD &&
 	# Abort conflicting merge
 	git merge --abort &&
-	test ! -f .git/MERGE_HEAD &&
+	test_path_is_missing .git/MERGE_HEAD &&
 	test "$pre_merge_head" = "$(git rev-parse HEAD)" &&
 	test -z "$(git diff)" &&
 	test -z "$(git diff --staged)"
@@ -105,7 +105,7 @@
 	git add foo &&
 	git diff --staged > expect &&
 	test_must_fail git merge clean_branch &&
-	test ! -f .git/MERGE_HEAD &&
+	test_path_is_missing .git/MERGE_HEAD &&
 	test "$pre_merge_head" = "$(git rev-parse HEAD)" &&
 	test -z "$(git diff)" &&
 	git diff --staged > actual &&
@@ -114,7 +114,7 @@
 
 test_expect_success 'Conflicting merge with dirty index fails' '
 	test_must_fail git merge conflict_branch &&
-	test ! -f .git/MERGE_HEAD &&
+	test_path_is_missing .git/MERGE_HEAD &&
 	test "$pre_merge_head" = "$(git rev-parse HEAD)" &&
 	test -z "$(git diff)" &&
 	git diff --staged > actual &&
@@ -129,10 +129,10 @@
 
 test_expect_success 'Abort clean merge with non-conflicting dirty worktree' '
 	git merge --no-commit clean_branch &&
-	test -f .git/MERGE_HEAD &&
+	test_path_is_file .git/MERGE_HEAD &&
 	# Abort merge
 	git merge --abort &&
-	test ! -f .git/MERGE_HEAD &&
+	test_path_is_missing .git/MERGE_HEAD &&
 	test "$pre_merge_head" = "$(git rev-parse HEAD)" &&
 	test -z "$(git diff --staged)" &&
 	git diff > actual &&
@@ -141,10 +141,10 @@
 
 test_expect_success 'Abort conflicting merge with non-conflicting dirty worktree' '
 	test_must_fail git merge conflict_branch &&
-	test -f .git/MERGE_HEAD &&
+	test_path_is_file .git/MERGE_HEAD &&
 	# Abort merge
 	git merge --abort &&
-	test ! -f .git/MERGE_HEAD &&
+	test_path_is_missing .git/MERGE_HEAD &&
 	test "$pre_merge_head" = "$(git rev-parse HEAD)" &&
 	test -z "$(git diff --staged)" &&
 	git diff > actual &&
@@ -159,7 +159,7 @@
 	echo xyzzy >> bar &&
 	git diff > expect &&
 	test_must_fail git merge --no-commit clean_branch &&
-	test ! -f .git/MERGE_HEAD &&
+	test_path_is_missing .git/MERGE_HEAD &&
 	test "$pre_merge_head" = "$(git rev-parse HEAD)" &&
 	test -z "$(git diff --staged)" &&
 	git diff > actual &&
@@ -168,7 +168,7 @@
 
 test_expect_success 'Fail conflicting merge with conflicting dirty worktree' '
 	test_must_fail git merge conflict_branch &&
-	test ! -f .git/MERGE_HEAD &&
+	test_path_is_missing .git/MERGE_HEAD &&
 	test "$pre_merge_head" = "$(git rev-parse HEAD)" &&
 	test -z "$(git diff --staged)" &&
 	git diff > actual &&
@@ -183,7 +183,7 @@
 	echo bart > bar &&
 	git diff > expect &&
 	test_must_fail git merge --no-commit clean_branch &&
-	test ! -f .git/MERGE_HEAD &&
+	test_path_is_missing .git/MERGE_HEAD &&
 	test "$pre_merge_head" = "$(git rev-parse HEAD)" &&
 	test -z "$(git diff --staged)" &&
 	git diff > actual &&
@@ -194,7 +194,7 @@
 	echo barf > bar &&
 	git diff > expect &&
 	test_must_fail git merge conflict_branch &&
-	test ! -f .git/MERGE_HEAD &&
+	test_path_is_missing .git/MERGE_HEAD &&
 	test "$pre_merge_head" = "$(git rev-parse HEAD)" &&
 	test -z "$(git diff --staged)" &&
 	git diff > actual &&