feat: add tests

Inspired by gliderlabs/docker-alpine

test/alpine.bats

@@ -0,0 +1,15 @@
+setup() {
+  docker history alpine >/dev/null 2>&1
+}
+
+@test "whoami" {
+  run docker run alpine whoami
+  [ $status -eq 0 ]
+  [ "${lines[0]}" = "app" ]
+}
+
+@test "workdir" {
+  run docker run alpine pwd
+  [ $status -eq 0 ]
+  [ "${lines[0]}" = "/app" ]
+}

test/debian.bats

@@ -0,0 +1,16 @@
+setup() {
+  docker history debian >/dev/null 2>&1
+}
+
+@test "whoami app" {
+  run docker run debian whoami
+  [ $status -eq 0 ]
+  [ "${lines[0]}" = "app" ]
+}
+
+@test "workdir" {
+  run docker run debian pwd
+  [ $status -eq 0 ]
+  [ "${lines[0]}" = "/app" ]
+}
+

test/ubuntu.bats

@@ -0,0 +1,16 @@
+setup() {
+  docker history ubuntu >/dev/null 2>&1
+}
+
+@test "whoami app" {
+  run docker run ubuntu whoami
+  [ $status -eq 0 ]
+  [ "${lines[0]}" = "app" ]
+}
+
+@test "workdir" {
+  run docker run ubuntu pwd
+  [ $status -eq 0 ]
+  [ "${lines[0]}" = "/app" ]
+}
+