Add unit tests for netinfo_to_resolv_conf

Use shunit2 for adding some unit tests to cover the functionality of
`_generate_hosts_content` and `netinfo_to_resolv_conf`.

Signed-off-by: Benjamin Drung <bdrung@debian.org>

debian/control

@@ -3,7 +3,7 @@ Section: utils
 Priority: optional
 Uploaders: Michael Prokop <mika@debian.org>, Ben Hutchings <benh@debian.org>
 Maintainer: Debian kernel team <debian-kernel@lists.debian.org>
-Build-Depends: debhelper-compat (= 12), bash-completion
+Build-Depends: debhelper-compat (= 12), bash-completion, shunit2 <!nocheck>
 Rules-Requires-Root: no
 Standards-Version: 4.1.5
 Vcs-Browser: https://salsa.debian.org/kernel-team/initramfs-tools

debian/rules

@@ -22,3 +22,8 @@ override_dh_install:
 
 override_dh_installinitramfs:
 	@:
+
+override_dh_auto_test:
+ifeq (,$(filter nocheck,$(DEB_BUILD_OPTIONS)))
+	tests/functions_test
+endif

tests/functions_test

@@ -0,0 +1,54 @@
+#!/bin/sh
+set -u
+
+# Unit tests for scripts/functions
+
+TEST_DIR="${0%/*}"
+ROOT_DIR="$TEST_DIR/.."
+CR="
+"
+
+oneTimeSetUp() {
+	. "$ROOT_DIR/scripts/functions"
+}
+
+HOSTS_FOOTER="
+# The following lines are desirable for IPv6 capable hosts
+::1     localhost ip6-localhost ip6-loopback
+ff02::1 ip6-allnodes
+ff02::2 ip6-allrouters"
+
+test_generate_hosts_content_with_domain() {
+	hosts_content=$(_generate_hosts_content example com)
+	assertEquals "127.0.0.1	localhost${CR}127.0.1.1	example.com	example${CR}${HOSTS_FOOTER}" "$hosts_content"
+}
+
+test_generate_hosts_content_without_domain() {
+	hosts_content=$(_generate_hosts_content example "")
+	assertEquals "127.0.0.1	localhost${CR}127.0.1.1	example${CR}${HOSTS_FOOTER}" "$hosts_content"
+}
+
+test_netinfo_to_resolv_conf_IPv4() {
+	resolv_conf=$(netinfo_to_resolv_conf - "$TEST_DIR/netinfo/net-eth0.conf")
+	assertEquals "domain example.net${CR}nameserver 192.0.2.42${CR}search example.net. example.com." "$resolv_conf"
+}
+
+test_netinfo_to_resolv_conf_duplicates() {
+	resolv_conf=$(netinfo_to_resolv_conf - "$TEST_DIR/netinfo/net-eth0.conf" "$TEST_DIR/netinfo/net-eth0.conf")
+	assertEquals "domain example.net${CR}nameserver 192.0.2.42${CR}search example.net. example.com." "$resolv_conf"
+}
+
+test_netinfo_to_resolv_conf_mutliple() {
+	resolv_conf=$(netinfo_to_resolv_conf - "$TEST_DIR/netinfo/net-eth0.conf" "$TEST_DIR/netinfo/net-eth1.conf")
+	assertEquals "domain example.org${CR}nameserver 192.0.2.42${CR}nameserver 192.0.2.84${CR}search example.net. example.com. example.org." "$resolv_conf"
+}
+
+test_netinfo_to_resolv_conf_write_output() {
+	tmpfile=$(mktemp -t initramfs-tools.XXXXXXXXXX)
+	netinfo_to_resolv_conf "$tmpfile" "$TEST_DIR/netinfo/net-eth0.conf"
+	assertEquals "domain example.net${CR}nameserver 192.0.2.42${CR}search example.net. example.com." "$(cat "$tmpfile")"
+	rm -f "$tmpfile"
+}
+
+# Load shUnit2.
+. shunit2

tests/netinfo/net-eth0.conf

@@ -0,0 +1,17 @@
+DEVICE='eth0'
+PROTO='dhcp'
+IPV4ADDR='192.0.2.101'
+IPV4BROADCAST='192.0.2.255'
+IPV4NETMASK='255.255.255.0'
+IPV4GATEWAY='192.0.2.1'
+IPV4DNS0='192.0.2.42'
+IPV4DNS1='0.0.0.0'
+HOSTNAME='example-host'
+DNSDOMAIN='example.net'
+NISDOMAIN=''
+ROOTSERVER='192.0.2.1'
+ROOTPATH=''
+filename=''
+UPTIME='4'
+DHCPLEASETIME='86400'
+DOMAINSEARCH='example.net. example.com.'

tests/netinfo/net-eth1.conf

@@ -0,0 +1,17 @@
+DEVICE='eth1'
+PROTO='dhcp'
+IPV4ADDR='192.0.2.150'
+IPV4BROADCAST='192.0.2.255'
+IPV4NETMASK='255.255.255.0'
+IPV4GATEWAY='192.0.2.254'
+IPV4DNS0='192.0.2.84'
+IPV4DNS1='0.0.0.0'
+HOSTNAME='example-host'
+DNSDOMAIN='example.org'
+NISDOMAIN=''
+ROOTSERVER='192.0.2.254'
+ROOTPATH=''
+filename=''
+UPTIME='4'
+DHCPLEASETIME='86400'
+DOMAINSEARCH='example.org.'