issue-#5

add Flatten function
add Test case for Flatten() function

Author: Dean Karn

validator.go

@@ -31,7 +31,7 @@ type FieldValidationError struct {
 
 // This is intended for use in development + debugging and not intended to be a production error message.
 // it also allows FieldValidationError to be used as an Error interface
-func (e FieldValidationError) Error() string {
+func (e *FieldValidationError) Error() string {
 	return fmt.Sprintf(validationFieldErrMsg, e.Field, e.ErrorTag)
 }
 
@@ -48,7 +48,7 @@ type StructValidationErrors struct {
 
 // This is intended for use in development + debugging and not intended to be a production error message.
 // it also allows StructValidationErrors to be used as an Error interface
-func (e StructValidationErrors) Error() string {
+func (e *StructValidationErrors) Error() string {
 
 	s := fmt.Sprintf(validationStructErrMsg, e.Struct)
 
@@ -63,6 +63,35 @@ func (e StructValidationErrors) Error() string {
 	return fmt.Sprintf("%s\n\n", s)
 }
 
+// Flatten flattens the StructValidationErrors hierarchical sctructure into a flat namespace style field name
+// for those that want/need it
+func (e *StructValidationErrors) Flatten() map[string]*FieldValidationError {
+
+	if e == nil {
+		return nil
+	}
+
+	errs := map[string]*FieldValidationError{}
+
+	for _, f := range e.Errors {
+
+		errs[f.Field] = f
+	}
+
+	for key, val := range e.StructErrors {
+
+		otherErrs := val.Flatten()
+
+		for _, f2 := range otherErrs {
+
+			f2.Field = fmt.Sprintf("%s.%s", key, f2.Field)
+			errs[f2.Field] = f2
+		}
+	}
+
+	return errs
+}
+
 // ValidationFunc that accepts the value of a field and parameter for use in validation (parameter not always used or needed)
 type ValidationFunc func(v interface{}, param string) bool
 

validator_test.go

@@ -87,6 +87,72 @@ func AssertFieldError(s *validator.StructValidationErrors, field string, expecte
 	c.Assert(val.ErrorTag, Equals, expectedTag)
 }
 
+func AssertMapFieldError(s map[string]*validator.FieldValidationError, field string, expectedTag string, c *C) {
+
+	val, ok := s[field]
+	c.Assert(ok, Equals, true)
+	c.Assert(val, NotNil)
+	c.Assert(val.Field, Equals, field)
+	c.Assert(val.ErrorTag, Equals, expectedTag)
+}
+
+func (ms *MySuite) TestFlattening(c *C) {
+
+	tSuccess := &TestString{
+		Required:  "Required",
+		Len:       "length==10",
+		Min:       "min=1",
+		Max:       "1234567890",
+		MinMax:    "12345",
+		OmitEmpty: "",
+		Sub: &SubTest{
+			Test: "1",
+		},
+		SubIgnore: &SubTest{
+			Test: "",
+		},
+		Anonymous: struct {
+			A string `validate:"required"`
+		}{
+			A: "1",
+		},
+	}
+
+	err1 := validator.ValidateStruct(tSuccess).Flatten()
+	c.Assert(err1, IsNil)
+
+	tFail := &TestString{
+		Required:  "",
+		Len:       "",
+		Min:       "",
+		Max:       "12345678901",
+		MinMax:    "",
+		OmitEmpty: "12345678901",
+		Sub: &SubTest{
+			Test: "",
+		},
+		Anonymous: struct {
+			A string `validate:"required"`
+		}{
+			A: "",
+		},
+	}
+
+	err2 := validator.ValidateStruct(tFail).Flatten()
+
+	// Assert Top Level
+	c.Assert(err2, NotNil)
+
+	// Assert Fields
+	AssertMapFieldError(err2, "Len", "len", c)
+
+	// Assert Struct Field
+	AssertMapFieldError(err2, "Sub.Test", "required", c)
+
+	// Assert Anonymous Struct Field
+	AssertMapFieldError(err2, "Anonymous.A", "required", c)
+}
+
 func (ms *MySuite) TestStructStringValidation(c *C) {
 
 	tSuccess := &TestString{
@@ -132,6 +198,7 @@ func (ms *MySuite) TestStructStringValidation(c *C) {
 	err = validator.ValidateStruct(tFail)
 
 	// Assert Top Level
+	c.Assert(err, NotNil)
 	c.Assert(err.Struct, Equals, "TestString")
 	c.Assert(len(err.Errors), Equals, 6)
 	c.Assert(len(err.StructErrors), Equals, 2)
@@ -181,6 +248,7 @@ func (ms *MySuite) TestStructInt32Validation(c *C) {
 	err = validator.ValidateStruct(tFail)
 
 	// Assert Top Level
+	c.Assert(err, NotNil)
 	c.Assert(err.Struct, Equals, "TestInt32")
 	c.Assert(len(err.Errors), Equals, 6)
 	c.Assert(len(err.StructErrors), Equals, 0)
@@ -220,6 +288,7 @@ func (ms *MySuite) TestStructUint64Validation(c *C) {
 	err = validator.ValidateStruct(tFail)
 
 	// Assert Top Level
+	c.Assert(err, NotNil)
 	c.Assert(err.Struct, Equals, "TestUint64")
 	c.Assert(len(err.Errors), Equals, 6)
 	c.Assert(len(err.StructErrors), Equals, 0)
@@ -259,6 +328,7 @@ func (ms *MySuite) TestStructFloat64Validation(c *C) {
 	err = validator.ValidateStruct(tFail)
 
 	// Assert Top Level
+	c.Assert(err, NotNil)
 	c.Assert(err.Struct, Equals, "TestFloat64")
 	c.Assert(len(err.Errors), Equals, 6)
 	c.Assert(len(err.StructErrors), Equals, 0)
@@ -298,6 +368,7 @@ func (ms *MySuite) TestStructSliceValidation(c *C) {
 	err = validator.ValidateStruct(tFail)
 
 	// Assert Top Level
+	c.Assert(err, NotNil)
 	c.Assert(err.Struct, Equals, "TestSlice")
 	c.Assert(len(err.Errors), Equals, 6)
 	c.Assert(len(err.StructErrors), Equals, 0)