lib-log-graph: move check_graph function

check_graph is a function shared in the test files t4215 and t6016 used
to format the output graph, but instead of being in a file called by
both test, the function code is repeated in each file.

Move check_graph to lib-log-graph.sh file which both tests already
import graph functions from, renaming it to lib_test_check_graph.

This function is needed for the following commit which includes graph
tests in a new file and requires check_graph.

Mentored-by: Karthik Nayak <karthik.188@gmail.com>
Mentored-by: Chandra Pratap <chandrapratap3519@gmail.com>
Signed-off-by: Pablo Sabater <pabloosabaterr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/lib-log-graph.sh

@@ -26,3 +26,8 @@ lib_test_cmp_colored_graph () {
 	test_decode_color <output.colors.raw | sed "s/ *\$//" >output.colors &&
 	test_cmp expect.colors output.colors
 }
+
+lib_test_check_graph () {
+	cat >expect &&
+	lib_test_cmp_graph --format=%s "$@"
+}

t/t4215-log-skewed-merges.sh

@@ -5,11 +5,6 @@ test_description='git log --graph of skewed merges'
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-log-graph.sh
 
-check_graph () {
-	cat >expect &&
-	lib_test_cmp_graph --format=%s "$@"
-}
-
 test_expect_success 'log --graph with merge fusing with its left and right neighbors' '
 	git checkout --orphan _p &&
 	test_commit A &&
@@ -21,7 +16,7 @@ test_expect_success 'log --graph with merge fusing with its left and right neigh
 	git checkout _p && git merge --no-ff _r -m G &&
 	git checkout @^^ && git merge --no-ff _p -m H &&
 
-	check_graph <<-\EOF
+	lib_test_check_graph <<-\EOF
 	*   H
 	|\
 	| *   G
@@ -49,7 +44,7 @@ test_expect_success 'log --graph with left-skewed merge' '
 	git checkout 0_p && git merge --no-ff 0_s -m 0_G &&
 	git checkout @^ && git merge --no-ff 0_q 0_r 0_t 0_p -m 0_H &&
 
-	check_graph <<-\EOF
+	lib_test_check_graph <<-\EOF
 	*-----.   0_H
 	|\ \ \ \
 	| | | | * 0_G
@@ -83,7 +78,7 @@ test_expect_success 'log --graph with nested left-skewed merge' '
 	git checkout 1_p && git merge --no-ff 1_r -m 1_G &&
 	git checkout @^^ && git merge --no-ff 1_p -m 1_H &&
 
-	check_graph <<-\EOF
+	lib_test_check_graph <<-\EOF
 	*   1_H
 	|\
 	| *   1_G
@@ -115,7 +110,7 @@ test_expect_success 'log --graph with nested left-skewed merge following normal
 	git checkout -b 2_s @^^ && git merge --no-ff 2_q -m 2_J &&
 	git checkout 2_p && git merge --no-ff 2_s -m 2_K &&
 
-	check_graph <<-\EOF
+	lib_test_check_graph <<-\EOF
 	*   2_K
 	|\
 	| *   2_J
@@ -151,7 +146,7 @@ test_expect_success 'log --graph with nested right-skewed merge following left-s
 	git checkout 3_p && git merge --no-ff 3_r -m 3_H &&
 	git checkout @^^ && git merge --no-ff 3_p -m 3_J &&
 
-	check_graph <<-\EOF
+	lib_test_check_graph <<-\EOF
 	*   3_J
 	|\
 	| *   3_H
@@ -182,7 +177,7 @@ test_expect_success 'log --graph with right-skewed merge following a left-skewed
 	git merge --no-ff 4_p -m 4_G &&
 	git checkout @^^ && git merge --no-ff 4_s -m 4_H &&
 
-	check_graph --date-order <<-\EOF
+	lib_test_check_graph --date-order <<-\EOF
 	*   4_H
 	|\
 	| *   4_G
@@ -218,7 +213,7 @@ test_expect_success 'log --graph with octopus merge with column joining its penu
 	git checkout 5_r &&
 	git merge --no-ff 5_s -m 5_H &&
 
-	check_graph <<-\EOF
+	lib_test_check_graph <<-\EOF
 	*   5_H
 	|\
 	| *-.   5_G
@@ -257,7 +252,7 @@ test_expect_success 'log --graph with multiple tips' '
 	git checkout 6_1 &&
 	git merge --no-ff 6_2 -m 6_I &&
 
-	check_graph 6_1 6_3 6_5 <<-\EOF
+	lib_test_check_graph 6_1 6_3 6_5 <<-\EOF
 	*   6_I
 	|\
 	| | *   6_H
@@ -334,7 +329,7 @@ test_expect_success 'log --graph with multiple tips' '
 	git checkout -b M_7 7_1 &&
 	git merge --no-ff 7_2 7_3 -m 7_M4 &&
 
-	check_graph M_1 M_3 M_5 M_7 <<-\EOF
+	lib_test_check_graph M_1 M_3 M_5 M_7 <<-\EOF
 	*   7_M1
 	|\
 	| | *   7_M2
@@ -371,7 +366,7 @@ test_expect_success 'log --graph with multiple tips' '
 '
 
 test_expect_success 'log --graph --graph-lane-limit=2 limited to two lanes' '
-	check_graph --graph-lane-limit=2 M_7 <<-\EOF
+	lib_test_check_graph --graph-lane-limit=2 M_7 <<-\EOF
 	*-.   7_M4
 	|\ \
 	| | * 7_G
@@ -388,7 +383,7 @@ test_expect_success 'log --graph --graph-lane-limit=2 limited to two lanes' '
 '
 
 test_expect_success 'log --graph --graph-lane-limit=1 truncate mid octopus merge' '
-	check_graph --graph-lane-limit=1 M_7 <<-\EOF
+	lib_test_check_graph --graph-lane-limit=1 M_7 <<-\EOF
 	*-~  7_M4
 	|\~
 	| ~ 7_G
@@ -405,7 +400,7 @@ test_expect_success 'log --graph --graph-lane-limit=1 truncate mid octopus merge
 '
 
 test_expect_success 'log --graph --graph-lane-limit=3 limited to three lanes' '
-	check_graph --graph-lane-limit=3 M_1 M_3 M_5 M_7 <<-\EOF
+	lib_test_check_graph --graph-lane-limit=3 M_1 M_3 M_5 M_7 <<-\EOF
 	*   7_M1
 	|\
 	| | *   7_M2
@@ -441,7 +436,7 @@ test_expect_success 'log --graph --graph-lane-limit=3 limited to three lanes' '
 '
 
 test_expect_success 'log --graph --graph-lane-limit=6 check if it only shows first of 3 parent merge' '
-	check_graph --graph-lane-limit=6 M_1 M_3 M_5 M_7 <<-\EOF
+	lib_test_check_graph --graph-lane-limit=6 M_1 M_3 M_5 M_7 <<-\EOF
 	*   7_M1
 	|\
 	| | *   7_M2
@@ -478,7 +473,7 @@ test_expect_success 'log --graph --graph-lane-limit=6 check if it only shows fir
 '
 
 test_expect_success 'log --graph --graph-lane-limit=7 check if it shows all 3 parent merge' '
-	check_graph --graph-lane-limit=7 M_1 M_3 M_5 M_7 <<-\EOF
+	lib_test_check_graph --graph-lane-limit=7 M_1 M_3 M_5 M_7 <<-\EOF
 	*   7_M1
 	|\
 	| | *   7_M2

t/t6016-rev-list-graph-simplify-history.sh

@@ -13,11 +13,6 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-log-graph.sh
 
-check_graph () {
-	cat >expect &&
-	lib_test_cmp_graph --format=%s "$@"
-}
-
 test_expect_success 'set up rev-list --graph test' '
 	# 3 commits on branch A
 	test_commit A1 foo.txt &&
@@ -54,7 +49,7 @@ test_expect_success 'set up rev-list --graph test' '
 '
 
 test_expect_success '--graph --all' '
-	check_graph --all <<-\EOF
+	lib_test_check_graph --all <<-\EOF
 	* A7
 	*   A6
 	|\
@@ -82,7 +77,7 @@ test_expect_success '--graph --all' '
 # that undecorated merges are interesting, even with --simplify-by-decoration
 test_expect_success '--graph --simplify-by-decoration' '
 	git tag -d A4 &&
-	check_graph --all --simplify-by-decoration <<-\EOF
+	lib_test_check_graph --all --simplify-by-decoration <<-\EOF
 	* A7
 	*   A6
 	|\
@@ -114,7 +109,7 @@ test_expect_success 'setup: get rid of decorations on B' '
 
 # Graph with branch B simplified away
 test_expect_success '--graph --simplify-by-decoration prune branch B' '
-	check_graph --simplify-by-decoration --all <<-\EOF
+	lib_test_check_graph --simplify-by-decoration --all <<-\EOF
 	* A7
 	*   A6
 	|\
@@ -133,7 +128,7 @@ test_expect_success '--graph --simplify-by-decoration prune branch B' '
 '
 
 test_expect_success '--graph --full-history -- bar.txt' '
-	check_graph --full-history --all -- bar.txt <<-\EOF
+	lib_test_check_graph --full-history --all -- bar.txt <<-\EOF
 	* A7
 	*   A6
 	|\
@@ -148,7 +143,7 @@ test_expect_success '--graph --full-history -- bar.txt' '
 '
 
 test_expect_success '--graph --full-history --simplify-merges -- bar.txt' '
-	check_graph --full-history --simplify-merges --all -- bar.txt <<-\EOF
+	lib_test_check_graph --full-history --simplify-merges --all -- bar.txt <<-\EOF
 	* A7
 	*   A6
 	|\
@@ -161,7 +156,7 @@ test_expect_success '--graph --full-history --simplify-merges -- bar.txt' '
 '
 
 test_expect_success '--graph -- bar.txt' '
-	check_graph --all -- bar.txt <<-\EOF
+	lib_test_check_graph --all -- bar.txt <<-\EOF
 	* A7
 	* A5
 	* A3
@@ -172,7 +167,7 @@ test_expect_success '--graph -- bar.txt' '
 '
 
 test_expect_success '--graph --sparse -- bar.txt' '
-	check_graph --sparse --all -- bar.txt <<-\EOF
+	lib_test_check_graph --sparse --all -- bar.txt <<-\EOF
 	* A7
 	* A6
 	* A5
@@ -189,7 +184,7 @@ test_expect_success '--graph --sparse -- bar.txt' '
 '
 
 test_expect_success '--graph ^C4' '
-	check_graph --all ^C4 <<-\EOF
+	lib_test_check_graph --all ^C4 <<-\EOF
 	* A7
 	* A6
 	* A5
@@ -202,7 +197,7 @@ test_expect_success '--graph ^C4' '
 '
 
 test_expect_success '--graph ^C3' '
-	check_graph --all ^C3 <<-\EOF
+	lib_test_check_graph --all ^C3 <<-\EOF
 	* A7
 	*   A6
 	|\
@@ -220,7 +215,7 @@ test_expect_success '--graph ^C3' '
 # that important, but this test depends on it.  If the ordering ever changes
 # in the code, we'll need to update this test.
 test_expect_success '--graph --boundary ^C3' '
-	check_graph --boundary --all ^C3 <<-\EOF
+	lib_test_check_graph --boundary --all ^C3 <<-\EOF
 	* A7
 	*   A6
 	|\