t: add coverage of -L color short option

Problem: In several tests the --color option is tested but either
the short -L option is not tested or it is not tested with arguments.

Add additionl tests in

t0009-dmesg.t
t1008-kvs-eventlog.t
t2230-job-info-lookup.t
t3303-system-healthcheck.t

t/t0009-dmesg.t

@@ -138,16 +138,20 @@ test_expect_success 'dmesg -H, --human --delta works' '
 test_expect_success 'dmesg --delta without --human fails' '
 	test_must_fail flux dmesg --delta
 '
-test_expect_success 'dmesg -H, --human --color works' '
-	flux dmesg --human --color | sed -n 1p | grep "^" &&
-	flux dmesg --human --color | sed -n 2p | grep "^"
-'
-test_expect_success 'dmesg colorizes lines by severity' '
-	for s in emerg alert crit err warning notice debug; do
-	    flux logger --severity=$s severity=$s &&
-	    flux dmesg --human --color | grep "[^ ]*severity=$s"
-	done
-'
+
+for opt in "-L" "-Lalways" "--color" "--color=always"; do
+	test_expect_success "dmesg -H, --human $opt works" '
+		flux dmesg --human $opt | sed -n 1p | grep "^" &&
+		flux dmesg --human $opt | sed -n 2p | grep "^"
+	'
+	test_expect_success "dmesg colorizes lines by severity" '
+		for s in emerg alert crit err warning notice debug; do
+		    flux logger --severity=$s severity=$s &&
+		    flux dmesg --human $opt | grep "[^ ]*severity=$s"
+		done
+	'
+done
+
 test_expect_success 'dmesg with invalid --color option fails' '
 	test_must_fail flux dmesg --color=foo
 '

t/t1008-kvs-eventlog.t

@@ -69,7 +69,7 @@ test_expect_success 'flux kvs eventlog get/wait-event reject invalid --color' '
 	test_must_fail flux kvs eventlog get --color=foo test.human &&
 	test_must_fail flux kvs eventlog wait-event --color=foo test.human primus
 '
-for opt in "-L" "--color" "--color=always"; do
+for opt in "-L" "-Lalways" "--color" "--color=always"; do
 	test_expect_success "flux kvs eventlog get $opt forces color on" '
 		name=notty${opt##--color=} &&
 		outfile=color-${name:-default}.out &&

t/t2230-job-info-lookup.t

@@ -255,7 +255,7 @@ test_expect_success 'flux job eventlog/wait-event reject invalid --color' '
         test_must_fail flux job eventlog --color=foo $jobid &&
         test_must_fail flux job wait-event --color=foo $jobid
 '
-for opt in "-L" "--color" "--color=always"; do
+for opt in "-L" "-Lalways" "--color" "--color=always"; do
         test_expect_success "flux job eventlog $opt forces color on" '
                 name=notty${opt##--color=} &&
                 outfile=color-${name:-default}.out &&

t/t3303-system-healthcheck.t

@@ -97,9 +97,13 @@ test_expect_success 'flux overlay status --highlight expected failures' '
 '
 
 test_expect_success 'flux overlay status --color option works' '
+	test_must_fail flux overlay status -Lfoo &&
 	test_must_fail flux overlay status --color=foo &&
+	flux overlay status -Lnever --highlight=0 | grep "<<0" &&
 	flux overlay status --color=never --highlight=0 | grep "<<0" &&
+	flux overlay status -Lauto --highlight=0 | grep "<<0" &&
 	flux overlay status --color=auto --highlight=0 | grep "<<0" &&
+	flux overlay status -L --highlight=0 | grep "\[" &&
 	flux overlay status --color --highlight=0 | grep "\["
 '