test-reach: add run_three_modes method

The 'test_three_modes' method assumes we are using the 'test-tool
reach' command for our test. However, we may want to use the data
shape of our commit graph and the three modes (no commit-graph,
full commit-graph, partial commit-graph) for other git commands.

Split test_three_modes to be a simple translation on a more general
run_three_modes method that executes the given command and tests
the actual output to the expected output.

Signed-off-by: Derrick Stolee <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: derrickstolee

t/t6600-test-reach.sh

@@ -53,18 +53,22 @@ test_expect_success 'setup' '
 	git config core.commitGraph true
 '
 
-test_three_modes () {
+run_three_modes () {
 	test_when_finished rm -rf .git/objects/info/commit-graph &&
-	test-tool reach $1 <input >actual &&
+	"$@" <input >actual &&
 	test_cmp expect actual &&
 	cp commit-graph-full .git/objects/info/commit-graph &&
-	test-tool reach $1 <input >actual &&
+	"$@" <input >actual &&
 	test_cmp expect actual &&
 	cp commit-graph-half .git/objects/info/commit-graph &&
-	test-tool reach $1 <input >actual &&
+	"$@" <input >actual &&
 	test_cmp expect actual
 }
 
+test_three_modes () {
+	run_three_modes test-tool reach "$@"
+}
+
 test_expect_success 'ref_newer:miss' '
 	cat >input <<-\EOF &&
 	A:commit-5-7