[GSoC][PATCH v3 4/4] t: add test for git refs exists subcommand

[Meet Soni <meetsoni3017@gmail.com>]

Add a test script, `t/t1462-refs-exists.sh`, for the `git refs exists`
command.

This script acts as a simple driver, leveraging the shared test library
created in the preceding commit. It works by overriding the
`$git_show_ref_exists` variable to "git refs exists" and then sourcing the
shared library (`t/show-ref-exists-tests.sh`).

This approach ensures that `git refs exists` is tested against the
entire comprehensive test suite of `git show-ref --exists`, verifying
that it acts as a compatible drop-in replacement.

Mentored-by: Patrick Steinhardt <ps@pks.im>
Mentored-by: shejialuo <shejialuo@gmail.com>
Signed-off-by: Meet Soni <meetsoni3017@gmail.com>
---
 t/meson.build          |  1 +
 t/t1462-refs-exists.sh | 10 ++++++++++
 2 files changed, 11 insertions(+)
 create mode 100755 t/t1462-refs-exists.sh

diff --git a/t/meson.build b/t/meson.build
index 4d6bc3d38e..93e9773ec8 100644
--- a/t/meson.build
+++ b/t/meson.build
@@ -211,6 +211,7 @@ integration_tests = [
   't1451-fsck-buffer.sh',
   't1460-refs-migrate.sh',
   't1461-refs-list.sh',
+  't1462-refs-exists.sh',
   't1500-rev-parse.sh',
   't1501-work-tree.sh',
   't1502-rev-parse-parseopt.sh',
diff --git a/t/t1462-refs-exists.sh b/t/t1462-refs-exists.sh
new file mode 100755
index 0000000000..349453c4ca
--- /dev/null
+++ b/t/t1462-refs-exists.sh
@@ -0,0 +1,10 @@
+#!/bin/sh
+
+test_description='refs exists'
+GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
+export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
+
+. ./test-lib.sh
+
+git_show_ref_exists='git refs exists'
+. "$TEST_DIRECTORY"/show-ref-exists-tests.sh
-- 
2.34.1