feat: add hide dotfiles param (#1148)

rules/rules.go

@@ -1,6 +1,7 @@
 package rules
 
 import (
+	"path/filepath"
 	"regexp"
 	"strings"
 )
@@ -18,6 +19,12 @@ type Rule struct {
 	Regexp *Regexp `json:"regexp"`
 }
 
+// MatchHidden matches paths with a basename
+// that begins with a dot.
+func MatchHidden(path string) bool {
+	return strings.HasPrefix(filepath.Base(path), ".")
+}
+
 // Matches matches a path against a rule.
 func (r *Rule) Matches(path string) bool {
 	if r.Regex {

rules/rules_test.go

@@ -0,0 +1,23 @@
+package rules
+
+import "testing"
+
+func TestMatchHidden(t *testing.T) {
+	cases := map[string]bool{
+		"/":                   false,
+		"/src":                false,
+		"/src/":               false,
+		"/.circleci":          true,
+		"/a/b/c/.docker.json": true,
+		".docker.json":        true,
+		"Dockerfile":          false,
+		"/Dockerfile":         false,
+	}
+
+	for path, want := range cases {
+		got := MatchHidden(path)
+		if got != want {
+			t.Errorf("MatchHidden(%s)=%v; want %v", path, got, want)
+		}
+	}
+}