refactor: move ErrMisconfiguration to top level

Signed-off-by: Xe Iaso <me@xeiaso.net>

errors.go

@@ -0,0 +1,7 @@
+package anubis
+
+import "errors"
+
+var (
+	ErrMisconfiguration = errors.New("[unexpected] policy: administrator misconfiguration")
+)

lib/policy/checker.go

@@ -8,15 +8,12 @@ import (
 	"regexp"
 	"strings"
 
+	"github.com/TecharoHQ/anubis"
 	"github.com/TecharoHQ/anubis/internal"
 	"github.com/TecharoHQ/anubis/lib/policy/checker"
 	"github.com/gaissmai/bart"
 )
 
-var (
-	ErrMisconfiguration = errors.New("[unexpected] policy: administrator misconfiguration")
-)
-
 type RemoteAddrChecker struct {
 	prefixTable *bart.Lite
 	hash        string
@@ -28,7 +25,7 @@ func NewRemoteAddrChecker(cidrs []string) (checker.Impl, error) {
 	for _, cidr := range cidrs {
 		prefix, err := netip.ParsePrefix(cidr)
 		if err != nil {
-			return nil, fmt.Errorf("%w: range %s not parsing: %w", ErrMisconfiguration, cidr, err)
+			return nil, fmt.Errorf("%w: range %s not parsing: %w", anubis.ErrMisconfiguration, cidr, err)
 		}
 
 		table.Insert(prefix)
@@ -43,12 +40,12 @@ func NewRemoteAddrChecker(cidrs []string) (checker.Impl, error) {
 func (rac *RemoteAddrChecker) Check(r *http.Request) (bool, error) {
 	host := r.Header.Get("X-Real-Ip")
 	if host == "" {
-		return false, fmt.Errorf("%w: header X-Real-Ip is not set", ErrMisconfiguration)
+		return false, fmt.Errorf("%w: header X-Real-Ip is not set", anubis.ErrMisconfiguration)
 	}
 
 	addr, err := netip.ParseAddr(host)
 	if err != nil {
-		return false, fmt.Errorf("%w: %s is not an IP address: %w", ErrMisconfiguration, host, err)
+		return false, fmt.Errorf("%w: %s is not an IP address: %w", anubis.ErrMisconfiguration, host, err)
 	}
 
 	return rac.prefixTable.Contains(addr), nil
@@ -71,7 +68,7 @@ func NewUserAgentChecker(rexStr string) (checker.Impl, error) {
 func NewHeaderMatchesChecker(header, rexStr string) (checker.Impl, error) {
 	rex, err := regexp.Compile(strings.TrimSpace(rexStr))
 	if err != nil {
-		return nil, fmt.Errorf("%w: regex %s failed parse: %w", ErrMisconfiguration, rexStr, err)
+		return nil, fmt.Errorf("%w: regex %s failed parse: %w", anubis.ErrMisconfiguration, rexStr, err)
 	}
 	return &HeaderMatchesChecker{strings.TrimSpace(header), rex, internal.FastHash(header + ": " + rexStr)}, nil
 }
@@ -96,7 +93,7 @@ type PathChecker struct {
 func NewPathChecker(rexStr string) (checker.Impl, error) {
 	rex, err := regexp.Compile(strings.TrimSpace(rexStr))
 	if err != nil {
-		return nil, fmt.Errorf("%w: regex %s failed parse: %w", ErrMisconfiguration, rexStr, err)
+		return nil, fmt.Errorf("%w: regex %s failed parse: %w", anubis.ErrMisconfiguration, rexStr, err)
 	}
 	return &PathChecker{rex, internal.FastHash(rexStr)}, nil
 }