feat(checker): port path checker

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

lib/checker/path/config.go

@@ -0,0 +1,38 @@
+package path
+
+import (
+	"errors"
+	"fmt"
+	"regexp"
+)
+
+var (
+	ErrNoRegex      = errors.New("path: no regex is configured")
+	ErrInvalidRegex = errors.New("path: regex is invalid")
+)
+
+type fileConfig struct {
+	Regex string `json:"regex" yaml:"regex"`
+}
+
+func (fc fileConfig) String() string {
+	return fmt.Sprintf("regex=%q", fc.Regex)
+}
+
+func (fc fileConfig) Valid() error {
+	var errs []error
+
+	if fc.Regex == "" {
+		errs = append(errs, ErrNoRegex)
+	}
+
+	if _, err := regexp.Compile(fc.Regex); err != nil {
+		errs = append(errs, ErrInvalidRegex, err)
+	}
+
+	if len(errs) != 0 {
+		return errors.Join(errs...)
+	}
+
+	return nil
+}