OptionsRequired to CastAssoc (#33)

* add options required to cast assoc

* change assocRequired to required

changeset/cast_assoc.go

@@ -11,6 +11,7 @@ import (
 
 // CastAssocErrorMessage is the default error message for CastAssoc.
 var CastAssocErrorMessage = "{field} is invalid"
+var CastAssocRequiredMessage = "{field} is required"
 
 // ChangeFunc is changeset function.
 type ChangeFunc func(interface{}, params.Params) *Changeset
@@ -38,6 +39,13 @@ func CastAssoc(ch *Changeset, field string, fn ChangeFunc, opts ...Option) {
 		msg := strings.Replace(options.message, "{field}", field, 1)
 		AddError(ch, field, msg)
 	}
+
+	_, found := ch.changes[field]
+	if options.required && !found {
+		options.message = CastAssocRequiredMessage
+		msg := strings.Replace(options.message, "{field}", field, 1)
+		AddError(ch, field, msg)
+	}
 }
 
 func castOne(ch *Changeset, field string, fn ChangeFunc) bool {

changeset/cast_assoc_test.go

@@ -368,3 +368,45 @@ func TestCastAssoc_manyInnerChangesetError(t *testing.T) {
 	assert.Equal(t, "field4 is invalid", ch.Error().Error())
 	assert.Equal(t, "field3[0].field4", ch.Error().(errors.Error).Field)
 }
+
+func TestCastAssoc_optionRequired(t *testing.T) {
+	var data struct {
+		Field1 int
+		Field2 string
+		Field3 []Inner
+	}
+
+	changeInner := func(data interface{}, input params.Params) *Changeset {
+		ch := Cast(data, input, []string{"field4", "field5"})
+		return ch
+	}
+
+	invalidInput := params.Map{
+		"field1": 1,
+		"field2": "2",
+	}
+
+	validInput := params.Map{
+		"field1": 1,
+		"field2": "2",
+		"field3": []params.Map{
+			{
+				"field4": 14,
+				"field5": "15",
+			},
+			{
+				"field4": 24,
+				"field5": "25",
+			},
+		},
+	}
+
+	invalidCh := Cast(data, invalidInput, []string{"field1", "field2"})
+	CastAssoc(invalidCh, "field3", changeInner, Required(true))
+
+	validCh := Cast(data, validInput, []string{"field1", "field2"})
+	CastAssoc(validCh, "field3", changeInner, Required(true))
+
+	assert.NotNil(t, invalidCh.Errors())
+	assert.Nil(t, validCh.Errors())
+}

changeset/options.go

@@ -7,6 +7,7 @@ type Options struct {
 	name       string
 	exact      bool
 	changeOnly bool
+	required   bool
 }
 
 // Option for changeset operation.
@@ -52,3 +53,9 @@ func ChangeOnly(changeOnly bool) Option {
 		opts.changeOnly = changeOnly
 	}
 }
+
+func Required(required bool) Option {
+	return func(opts *Options) {
+		opts.required = required
+	}
+}

changeset/options_test.go

@@ -14,11 +14,13 @@ func TestOptions(t *testing.T) {
 		Name("name_fk"),
 		Exact(true),
 		ChangeOnly(true),
+		Required(true),
 	})
 
 	assert.Equal(t, "message", opts.message)
 	assert.Equal(t, 1000, opts.code)
 	assert.Equal(t, "name_fk", opts.name)
 	assert.Equal(t, true, opts.exact)
 	assert.Equal(t, true, opts.changeOnly)
+	assert.Equal(t, true, opts.required)
 }