lib: Fix no pager being used when PAGER and BAT_PAGER are unset (#57)

lib/pager.sh

@@ -113,10 +113,14 @@ _detect_pager() {
 # 3. Use PAGER
 _configure_pager() {
 	# shellcheck disable=SC2206
-	SCRIPT_PAGER_CMD=($PAGER)
 	SCRIPT_PAGER_ARGS=()
+	if [[ -n "${PAGER+x}" ]]; then
+		SCRIPT_PAGER_CMD=($PAGER)
+	else
+		SCRIPT_PAGER_CMD=("less")
+	fi
 
-	# Prefer the bat pager.
+	# Prefer the BAT_PAGER environment variable.
 	if [[ -n "${BAT_PAGER+x}" ]]; then
 		# [note]: This is intentional.
 		# shellcheck disable=SC2206

test/suite/lib_pager.sh

@@ -10,6 +10,14 @@ use_pager() {
 	_detect_pager
 }
 
+use_no_pager() {
+	unset BAT_PAGER
+	unset PAGER
+
+	_configure_pager
+	_detect_pager
+}
+
 use_bat_pager() {
 	unset PAGER
 	export BAT_PAGER="$1"
@@ -29,7 +37,9 @@ test:less_detection() {
 test:bat_detection() {
 	description "Ensure bat is replaced with less as pager"
 
-	(use_pager "bat"              && expect_equal "$(pager_name)" "less")
+	use_pager "bat"
+	expect_equal "$(pager_name)" "less"
+	expect array_contains "-R" in "${SCRIPT_PAGER_CMD[@]}"
 }
 
 test:less_version() {
@@ -88,6 +98,14 @@ test:env_bat_pager() {
 	expect_equal "${SCRIPT_PAGER_CMD[2]}" "not_more"
 }
 
+test:env_no_pager() {
+	description "Check that no PAGER or BAT_PAGER defaults to less"
+	
+	use_no_pager
+	expect_equal "${SCRIPT_PAGER_CMD[0]}" "less"
+	expect array_contains "-R" in "${SCRIPT_PAGER_CMD[@]}"
+}
+
 test:args_copied_from_pager() {
 	description "Check that the pager args are correct with PAGER."