fix: correct jail checks and add tests (#7)

tests/f2b.bats

@@ -0,0 +1,49 @@
+#!/usr/bin/env bats
+
+setup() {
+  export PATH="$BATS_TEST_DIRNAME/bin:$PATH"
+  mkdir -p "$BATS_TEST_DIRNAME/bin"
+  cat > "$BATS_TEST_DIRNAME/bin/fail2ban-client" <<'MOCK'
+#!/usr/bin/env bash
+cmd=$1
+shift
+case "$cmd" in
+  ping)
+    echo "pong"
+    ;;
+  status)
+    if [ -z "$1" ]; then
+      echo "Status"
+      echo "|- Number of jail:      2"
+      echo "\`- Jail list:   sshd, testjail"
+    else
+      echo "Status for the jail: $1"
+    fi
+    ;;
+  -V)
+    echo "0.11.2"
+    ;;
+  *)
+    echo "Mocked fail2ban-client: $cmd $*"
+    ;;
+esac
+MOCK
+  chmod +x "$BATS_TEST_DIRNAME/bin/fail2ban-client"
+}
+
+@test "status invalid jail" {
+  run "$BATS_TEST_DIRNAME/../f2b" status invalid
+  [ "$status" -eq 1 ]
+  [[ "$output" == *"Error: Jail 'invalid' does not exist."* ]]
+}
+
+@test "logs invalid jail" {
+  run "$BATS_TEST_DIRNAME/../f2b" logs invalid
+  [ "$status" -eq 1 ]
+  [[ "$output" == *"Error: Jail 'invalid' does not exist."* ]]
+}
+
+@test "logs valid jail" {
+  run "$BATS_TEST_DIRNAME/../f2b" logs sshd
+  [ "$status" -eq 0 ]
+}