From 43deea02afad4841f5592d14f9a2bec6b1319d40 Mon Sep 17 00:00:00 2001
From: NiseVoid <nisevoid@gmail.com>
Date: Fri, 24 Apr 2020 13:01:25 +0200
Subject: [PATCH] Support pointer values

---
 rules_test.go    |  1 +
 validate.go      | 31 ++++++++++++++++++++++++++++---
 validate_test.go | 21 +++++++++++++++++++++
 3 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/rules_test.go b/rules_test.go
index 32d632d..7f2fd57 100644
--- a/rules_test.go
+++ b/rules_test.go
@@ -131,6 +131,7 @@ func TestLenMinMax(t *testing.T) {
 }
 
 func check(t *testing.T, c interface{}, errCount int) {
+	t.Helper()
 	errs := Validate(c)
 	if len(errs) != errCount {
 		t.Errorf(`Case %T(%v) should get %d errors, but got %v`, c, c, errCount, errs)
diff --git a/validate.go b/validate.go
index 035d30c..50c840e 100644
--- a/validate.go
+++ b/validate.go
@@ -159,10 +159,17 @@ func getRules(rt reflect.Type) []rule {
 
 	for i := 0; i < rt.NumField(); i++ {
 		ft := rt.Field(i)
-		kind := simplifyKind(ft.Type.Kind())
+
+		kind := ft.Type.Kind()
+		var ptr bool
+		if kind == reflect.Ptr {
+			kind = ft.Type.Elem().Kind()
+			ptr = true
+		}
+		kind = simplifyKind(kind)
 
 		tags := strings.Split(ft.Tag.Get(`validate`), `,`)
-		rules = append(rules, getTagFuncs(i, ft, kind, tags)...)
+		rules = append(rules, getTagFuncs(i, ft, kind, tags, ptr)...)
 
 		// TODO: Add validator interface
 
@@ -185,7 +192,7 @@ func nest(ft reflect.StructField) func(reflect.Value) ([]ValidationError, bool)
 	}
 }
 
-func getTagFuncs(i int, ft reflect.StructField, kind reflect.Kind, tags []string) []rule {
+func getTagFuncs(i int, ft reflect.StructField, kind reflect.Kind, tags []string, ptr bool) []rule {
 	var rules []rule
 	for _, v := range tags {
 		if v == `` {
@@ -198,6 +205,13 @@ func getTagFuncs(i int, ft reflect.StructField, kind reflect.Kind, tags []string
 			value = parts[1]
 		}
 
+		kind := kind
+		ptr := ptr
+		if ptr && (tag == `optional` || strings.TrimPrefix(tag, `!`) == `required`) {
+			kind = reflect.Ptr
+			ptr = false
+		}
+
 		if tag == `optional` {
 			rules = append(rules, rule{i, func(rv reflect.Value) ([]ValidationError, bool) {
 				check, _ := getTagFunc(`required`, ``, kind)
@@ -221,6 +235,17 @@ func getTagFuncs(i int, ft reflect.StructField, kind reflect.Kind, tags []string
 			return []ValidationError{{Field: []Field{{nil, &ft}}, Check: tag, Value: value}}, false
 		}
 
+		if ptr {
+			oldF := f
+			f = func(rv reflect.Value) ([]ValidationError, bool) {
+				if rv.IsNil() {
+					return []ValidationError{{Field: []Field{{nil, &ft}}, Check: tag, Value: value}}, false
+				}
+
+				return oldF(rv.Elem())
+			}
+		}
+
 		rules = append(rules, rule{i, f})
 	}
 
diff --git a/validate_test.go b/validate_test.go
index 1e9b3b9..2a03c42 100644
--- a/validate_test.go
+++ b/validate_test.go
@@ -97,3 +97,24 @@ func TestNot(t *testing.T) {
 		t.Errorf(`Checknames missing !, got "%s" and "%s"`, errs[0].Check, errs[1].Check)
 	}
 }
+
+func TestPtr(t *testing.T) {
+	type s struct {
+		A *int `validate:"eq=3"`
+		B *int `validate:"optional,eq=3"`
+	}
+
+	two := 2
+	three := 3
+
+	var pass1 = s{&three, &three}
+	var pass2 = s{&three, nil}
+
+	var fail1 = s{&two, &two}
+	var fail2 = s{nil, nil}
+
+	check(t, pass1, 0)
+	check(t, pass2, 0)
+	check(t, fail1, 2)
+	check(t, fail2, 1)
+}