diff --git a/t/t4214-log-graph-octopus.sh b/t/t4214-log-graph-octopus.sh
index 40d27db674..e85cf07d2c 100755
--- a/t/t4214-log-graph-octopus.sh
+++ b/t/t4214-log-graph-octopus.sh
@@ -3,6 +3,7 @@
 test_description='git log --graph of skewed left octopus merge.'
 
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-log-graph.sh
 
 test_expect_success 'set up merge history' '
 	test_commit initial &&
@@ -24,7 +25,7 @@ test_expect_success 'set up merge history' '
 '
 
 test_expect_success 'log --graph with tricky octopus merge, no color' '
-	cat >expect.uncolored <<-\EOF &&
+	test_cmp_graph --pretty=tformat:%s --color=never --date-order left octopus-merge <<-\EOF
 	* left
 	| *-.   octopus-merge
 	|/|\ \
@@ -37,14 +38,11 @@ test_expect_success 'log --graph with tricky octopus merge, no color' '
 	|/
 	* initial
 	EOF
-	git log --color=never --graph --date-order --pretty=tformat:%s left octopus-merge >actual.raw &&
-	sed "s/ *\$//" actual.raw >actual &&
-	test_cmp expect.uncolored actual
 '
 
 test_expect_success 'log --graph with tricky octopus merge with colors' '
 	test_config log.graphColors red,green,yellow,blue,magenta,cyan &&
-	cat >expect.colors <<-\EOF &&
+	test_cmp_colored_graph --pretty=tformat:%s --date-order left octopus-merge <<-\EOF
 	* left
 	<RED>|<RESET> *<MAGENTA>-<RESET><MAGENTA>.<RESET>   octopus-merge
 	<RED>|<RESET><RED>/<RESET><YELLOW>|<RESET><BLUE>\<RESET> <MAGENTA>\<RESET>
@@ -57,16 +55,13 @@ test_expect_success 'log --graph with tricky octopus merge with colors' '
 	<MAGENTA>|<RESET><MAGENTA>/<RESET>
 	* initial
 	EOF
-	git log --color=always --graph --date-order --pretty=tformat:%s left octopus-merge >actual.colors.raw &&
-	test_decode_color <actual.colors.raw | sed "s/ *\$//" >actual.colors &&
-	test_cmp expect.colors actual.colors
 '
 
 # Repeat the previous two tests with "normal" octopus merge (i.e.,
 # without the first parent skewing to the "left" branch column).
 
 test_expect_success 'log --graph with normal octopus merge, no color' '
-	cat >expect.uncolored <<-\EOF &&
+	test_cmp_graph --pretty=tformat:%s --color=never --date-order octopus-merge <<-\EOF
 	*---.   octopus-merge
 	|\ \ \
 	| | | * 4
@@ -78,13 +73,11 @@ test_expect_success 'log --graph with normal octopus merge, no color' '
 	|/
 	* initial
 	EOF
-	git log --color=never --graph --date-order --pretty=tformat:%s octopus-merge >actual.raw &&
-	sed "s/ *\$//" actual.raw >actual &&
-	test_cmp expect.uncolored actual
 '
 
 test_expect_success 'log --graph with normal octopus merge with colors' '
-	cat >expect.colors <<-\EOF &&
+	test_config log.graphColors red,green,yellow,blue,magenta,cyan &&
+	test_cmp_colored_graph --pretty=tformat:%s --date-order octopus-merge <<-\EOF
 	*<YELLOW>-<RESET><YELLOW>-<RESET><BLUE>-<RESET><BLUE>.<RESET>   octopus-merge
 	<RED>|<RESET><GREEN>\<RESET> <YELLOW>\<RESET> <BLUE>\<RESET>
 	<RED>|<RESET> <GREEN>|<RESET> <YELLOW>|<RESET> * 4
@@ -96,14 +89,10 @@ test_expect_success 'log --graph with normal octopus merge with colors' '
 	<BLUE>|<RESET><BLUE>/<RESET>
 	* initial
 	EOF
-	test_config log.graphColors red,green,yellow,blue,magenta,cyan &&
-	git log --color=always --graph --date-order --pretty=tformat:%s octopus-merge >actual.colors.raw &&
-	test_decode_color <actual.colors.raw | sed "s/ *\$//" >actual.colors &&
-	test_cmp expect.colors actual.colors
 '
 
 test_expect_success 'log --graph with normal octopus merge and child, no color' '
-	cat >expect.uncolored <<-\EOF &&
+	test_cmp_graph --pretty=tformat:%s --color=never --date-order after-merge <<-\EOF
 	* after-merge
 	*---.   octopus-merge
 	|\ \ \
@@ -116,13 +105,11 @@ test_expect_success 'log --graph with normal octopus merge and child, no color'
 	|/
 	* initial
 	EOF
-	git log --color=never --graph --date-order --pretty=tformat:%s after-merge >actual.raw &&
-	sed "s/ *\$//" actual.raw >actual &&
-	test_cmp expect.uncolored actual
 '
 
 test_expect_success 'log --graph with normal octopus and child merge with colors' '
-	cat >expect.colors <<-\EOF &&
+	test_config log.graphColors red,green,yellow,blue,magenta,cyan &&
+	test_cmp_colored_graph --pretty=tformat:%s --date-order after-merge <<-\EOF
 	* after-merge
 	*<BLUE>-<RESET><BLUE>-<RESET><MAGENTA>-<RESET><MAGENTA>.<RESET>   octopus-merge
 	<GREEN>|<RESET><YELLOW>\<RESET> <BLUE>\<RESET> <MAGENTA>\<RESET>
@@ -135,14 +122,10 @@ test_expect_success 'log --graph with normal octopus and child merge with colors
 	<MAGENTA>|<RESET><MAGENTA>/<RESET>
 	* initial
 	EOF
-	test_config log.graphColors red,green,yellow,blue,magenta,cyan &&
-	git log --color=always --graph --date-order --pretty=tformat:%s after-merge >actual.colors.raw &&
-	test_decode_color <actual.colors.raw | sed "s/ *\$//" >actual.colors &&
-	test_cmp expect.colors actual.colors
 '
 
 test_expect_success 'log --graph with tricky octopus merge and its child, no color' '
-	cat >expect.uncolored <<-\EOF &&
+	test_cmp_graph --pretty=tformat:%s --color=never --date-order left after-merge <<-\EOF
 	* left
 	| * after-merge
 	| *-.   octopus-merge
@@ -156,14 +139,10 @@ test_expect_success 'log --graph with tricky octopus merge and its child, no col
 	|/
 	* initial
 	EOF
-	git log --color=never --graph --date-order --pretty=tformat:%s left after-merge >actual.raw &&
-	sed "s/ *\$//" actual.raw >actual &&
-	test_cmp expect.uncolored actual
 '
 
 test_expect_success 'log --graph with tricky octopus merge and its child with colors' '
-	test_config log.graphColors red,green,yellow,blue,magenta,cyan &&
-	cat >expect.colors <<-\EOF &&
+	test_cmp_colored_graph --pretty=tformat:%s --date-order left after-merge <<-\EOF
 	* left
 	<RED>|<RESET> * after-merge
 	<RED>|<RESET> *<CYAN>-<RESET><CYAN>.<RESET>   octopus-merge
@@ -177,13 +156,10 @@ test_expect_success 'log --graph with tricky octopus merge and its child with co
 	<CYAN>|<RESET><CYAN>/<RESET>
 	* initial
 	EOF
-	git log --color=always --graph --date-order --pretty=tformat:%s left after-merge >actual.colors.raw &&
-	test_decode_color <actual.colors.raw | sed "s/ *\$//" >actual.colors &&
-	test_cmp expect.colors actual.colors
 '
 
 test_expect_success 'log --graph with crossover in octopus merge, no color' '
-	cat >expect.uncolored <<-\EOF &&
+	test_cmp_graph --pretty=tformat:%s --date-order after-4 octopus-merge <<-\EOF
 	* after-4
 	| *---.   octopus-merge
 	| |\ \ \
@@ -200,14 +176,11 @@ test_expect_success 'log --graph with crossover in octopus merge, no color' '
 	|/
 	* initial
 	EOF
-	git log --color=never --graph --date-order --pretty=tformat:%s after-4 octopus-merge >actual.raw &&
-	sed "s/ *\$//" actual.raw >actual &&
-	test_cmp expect.uncolored actual
 '
 
 test_expect_success 'log --graph with crossover in octopus merge with colors' '
 	test_config log.graphColors red,green,yellow,blue,magenta,cyan &&
-	cat >expect.colors <<-\EOF &&
+	test_cmp_colored_graph --pretty=tformat:%s --date-order after-4 octopus-merge <<-\EOF
 	* after-4
 	<RED>|<RESET> *<BLUE>-<RESET><BLUE>-<RESET><RED>-<RESET><RED>.<RESET>   octopus-merge
 	<RED>|<RESET> <GREEN>|<RESET><YELLOW>\<RESET> <BLUE>\<RESET> <RED>\<RESET>
@@ -224,13 +197,10 @@ test_expect_success 'log --graph with crossover in octopus merge with colors' '
 	<MAGENTA>|<RESET><MAGENTA>/<RESET>
 	* initial
 	EOF
-	git log --color=always --graph --date-order --pretty=tformat:%s after-4 octopus-merge >actual.colors.raw &&
-	test_decode_color <actual.colors.raw | sed "s/ *\$//" >actual.colors &&
-	test_cmp expect.colors actual.colors
 '
 
 test_expect_success 'log --graph with crossover in octopus merge and its child, no color' '
-	cat >expect.uncolored <<-\EOF &&
+	test_cmp_graph --pretty=tformat:%s --date-order after-4 after-merge <<-\EOF
 	* after-4
 	| * after-merge
 	| *---.   octopus-merge
@@ -248,14 +218,11 @@ test_expect_success 'log --graph with crossover in octopus merge and its child,
 	|/
 	* initial
 	EOF
-	git log --color=never --graph --date-order --pretty=tformat:%s after-4 after-merge >actual.raw &&
-	sed "s/ *\$//" actual.raw >actual &&
-	test_cmp expect.uncolored actual
 '
 
 test_expect_success 'log --graph with crossover in octopus merge and its child with colors' '
 	test_config log.graphColors red,green,yellow,blue,magenta,cyan &&
-	cat >expect.colors <<-\EOF &&
+	test_cmp_colored_graph --pretty=tformat:%s --date-order after-4 after-merge <<-\EOF
 	* after-4
 	<RED>|<RESET> * after-merge
 	<RED>|<RESET> *<MAGENTA>-<RESET><MAGENTA>-<RESET><RED>-<RESET><RED>.<RESET>   octopus-merge
@@ -273,13 +240,10 @@ test_expect_success 'log --graph with crossover in octopus merge and its child w
 	<CYAN>|<RESET><CYAN>/<RESET>
 	* initial
 	EOF
-	git log --color=always --graph --date-order --pretty=tformat:%s after-4 after-merge >actual.colors.raw &&
-	test_decode_color <actual.colors.raw | sed "s/ *\$//" >actual.colors &&
-	test_cmp expect.colors actual.colors
 '
 
 test_expect_success 'log --graph with unrelated commit and octopus tip, no color' '
-	cat >expect.uncolored <<-\EOF &&
+	test_cmp_graph --pretty=tformat:%s --color=never --date-order --pretty=tformat:%s after-initial octopus-merge <<-\EOF
 	* after-initial
 	| *---.   octopus-merge
 	| |\ \ \
@@ -296,14 +260,11 @@ test_expect_success 'log --graph with unrelated commit and octopus tip, no color
 	|/
 	* initial
 	EOF
-	git log --color=never --graph --date-order --pretty=tformat:%s after-initial octopus-merge >actual.raw &&
-	sed "s/ *\$//" actual.raw >actual &&
-	test_cmp expect.uncolored actual
 '
 
 test_expect_success 'log --graph with unrelated commit and octopus tip with colors' '
 	test_config log.graphColors red,green,yellow,blue,magenta,cyan &&
-	cat >expect.colors <<-\EOF &&
+	test_cmp_colored_graph --pretty=tformat:%s --date-order after-initial octopus-merge <<-\EOF
 	* after-initial
 	<RED>|<RESET> *<BLUE>-<RESET><BLUE>-<RESET><MAGENTA>-<RESET><MAGENTA>.<RESET>   octopus-merge
 	<RED>|<RESET> <GREEN>|<RESET><YELLOW>\<RESET> <BLUE>\<RESET> <MAGENTA>\<RESET>
@@ -320,13 +281,10 @@ test_expect_success 'log --graph with unrelated commit and octopus tip with colo
 	<RED>|<RESET><RED>/<RESET>
 	* initial
 	EOF
-	git log --color=always --graph --date-order --pretty=tformat:%s after-initial octopus-merge >actual.colors.raw &&
-	test_decode_color <actual.colors.raw | sed "s/ *\$//" >actual.colors &&
-	test_cmp expect.colors actual.colors
 '
 
 test_expect_success 'log --graph with unrelated commit and octopus child, no color' '
-	cat >expect.uncolored <<-\EOF &&
+	test_cmp_graph --pretty=tformat:%s --color=never --date-order after-initial after-merge <<-\EOF
 	* after-initial
 	| * after-merge
 	| *---.   octopus-merge
@@ -344,14 +302,11 @@ test_expect_success 'log --graph with unrelated commit and octopus child, no col
 	|/
 	* initial
 	EOF
-	git log --color=never --graph --date-order --pretty=tformat:%s after-initial after-merge >actual.raw &&
-	sed "s/ *\$//" actual.raw >actual &&
-	test_cmp expect.uncolored actual
 '
 
 test_expect_success 'log --graph with unrelated commit and octopus child with colors' '
 	test_config log.graphColors red,green,yellow,blue,magenta,cyan &&
-	cat >expect.colors <<-\EOF &&
+	test_cmp_colored_graph --pretty=tformat:%s --date-order after-initial after-merge <<-\EOF
 	* after-initial
 	<RED>|<RESET> * after-merge
 	<RED>|<RESET> *<MAGENTA>-<RESET><MAGENTA>-<RESET><CYAN>-<RESET><CYAN>.<RESET>   octopus-merge
@@ -369,9 +324,6 @@ test_expect_success 'log --graph with unrelated commit and octopus child with co
 	<RED>|<RESET><RED>/<RESET>
 	* initial
 	EOF
-	git log --color=always --graph --date-order --pretty=tformat:%s after-initial after-merge >actual.colors.raw &&
-	test_decode_color <actual.colors.raw | sed "s/ *\$//" >actual.colors &&
-	test_cmp expect.colors actual.colors
 '
 
 test_done
