From 498124539d3c9a130bd3abdd9f597de33898cec8 Mon Sep 17 00:00:00 2001
From: Will May <will.j.may@gmail.com>
Date: Mon, 30 May 2022 08:46:32 +0100
Subject: [PATCH] Expose the struct the field is contained within

This allows users of `FieldError` to be able to query information about
the struct the field is contained within. This information can then be
used to work out what to display when the param field points to another
field, such as with `gtfield`, and a tag name function has been
registered.
---
 errors.go         |  9 +++++++++
 validator.go      |  5 +++++
 validator_test.go | 46 ++++++++++++++++++++++++----------------------
 3 files changed, 38 insertions(+), 22 deletions(-)

diff --git a/errors.go b/errors.go
index 9a1b1ab..91b16fc 100644
--- a/errors.go
+++ b/errors.go
@@ -158,6 +158,9 @@ type FieldError interface {
 
 	// Error returns the FieldError's message
 	Error() string
+
+	// Parent returns the Type of the struct that the StructField is contained within
+	Parent() reflect.Type
 }
 
 // compile time interface checks
@@ -179,6 +182,7 @@ type fieldError struct {
 	param          string
 	kind           reflect.Kind
 	typ            reflect.Type
+	parent         reflect.Type
 }
 
 // Tag returns the validation tag that failed.
@@ -254,6 +258,11 @@ func (fe *fieldError) Error() string {
 	return fmt.Sprintf(fieldErrMsg, fe.ns, fe.Field(), fe.tag)
 }
 
+// Parent returns the Type of the struct that the StructField is contained within
+func (fe *fieldError) Parent() reflect.Type {
+	return fe.parent
+}
+
 // Translate returns the FieldError's translated error
 // from the provided 'ut.Translator' and registered 'TranslationFunc'
 //
diff --git a/validator.go b/validator.go
index 80da095..3a7a8e2 100644
--- a/validator.go
+++ b/validator.go
@@ -154,6 +154,7 @@ func (v *validate) traverseField(ctx context.Context, parent reflect.Value, curr
 						param:          ct.param,
 						kind:           kind,
 						typ:            current.Type(),
+						parent:         parent.Type(),
 					},
 				)
 				return
@@ -199,6 +200,7 @@ func (v *validate) traverseField(ctx context.Context, parent reflect.Value, curr
 								param:          ct.param,
 								kind:           kind,
 								typ:            typ,
+								parent:         parent.Type(),
 							},
 						)
 						return
@@ -413,6 +415,7 @@ OUTER:
 								param:          ct.param,
 								kind:           kind,
 								typ:            typ,
+								parent:         parent.Type(),
 							},
 						)
 
@@ -433,6 +436,7 @@ OUTER:
 								param:          ct.param,
 								kind:           kind,
 								typ:            typ,
+								parent:         parent.Type(),
 							},
 						)
 					}
@@ -474,6 +478,7 @@ OUTER:
 						param:          ct.param,
 						kind:           kind,
 						typ:            typ,
+						parent:         parent.Type(),
 					},
 				)
 
diff --git a/validator_test.go b/validator_test.go
index 1ebdea5..62d4331 100644
--- a/validator_test.go
+++ b/validator_test.go
@@ -367,6 +367,7 @@ func TestStructLevelInvalidError(t *testing.T) {
 	Equal(t, fe.ActualTag(), "required")
 	Equal(t, fe.Kind(), reflect.Invalid)
 	Equal(t, fe.Type(), reflect.TypeOf(nil))
+	Equal(t, fe.Parent(), reflect.TypeOf(nil))
 }
 
 func TestNameNamespace(t *testing.T) {
@@ -8624,6 +8625,7 @@ func TestStructSliceValidation(t *testing.T) {
 	Equal(t, fe.Param(), "10")
 	Equal(t, fe.Kind(), reflect.Slice)
 	Equal(t, fe.Type(), reflect.TypeOf([]int{}))
+	Equal(t, fe.Parent(), reflect.TypeOf(TestSlice{}))
 
 	_, ok := fe.Value().([]int)
 	Equal(t, ok, true)
@@ -12264,25 +12266,25 @@ func TestCreditCardFormatValidation(t *testing.T) {
 }
 
 func TestMultiOrOperatorGroup(t *testing.T) {
- 	tests := []struct {
- 		Value    int `validate:"eq=1|gte=5,eq=1|lt=7"`
- 		expected bool
- 	}{
- 		{1, true}, {2, false}, {5, true}, {6, true}, {8, false},
- 	}
-
- 	validate := New()
-
- 	for i, test := range tests {
- 		errs := validate.Struct(test)
- 		if test.expected {
- 			if !IsEqual(errs, nil) {
- 				t.Fatalf("Index: %d multi_group_of_OR_operators failed Error: %s", i, errs)
- 			}
- 		} else {
- 			if IsEqual(errs, nil) {
- 				t.Fatalf("Index: %d multi_group_of_OR_operators should have errs", i)
- 			}
- 		}
- 	}
- }
+	tests := []struct {
+		Value    int `validate:"eq=1|gte=5,eq=1|lt=7"`
+		expected bool
+	}{
+		{1, true}, {2, false}, {5, true}, {6, true}, {8, false},
+	}
+
+	validate := New()
+
+	for i, test := range tests {
+		errs := validate.Struct(test)
+		if test.expected {
+			if !IsEqual(errs, nil) {
+				t.Fatalf("Index: %d multi_group_of_OR_operators failed Error: %s", i, errs)
+			}
+		} else {
+			if IsEqual(errs, nil) {
+				t.Fatalf("Index: %d multi_group_of_OR_operators should have errs", i)
+			}
+		}
+	}
+}