Merge pull request #107 from alecsammon/omitempty

Add support for `omitempty` field tag to exclude empty values from queries and headers

README.md

@@ -56,6 +56,7 @@ type ListUsersInput struct {
 	Page     int     `in:"query=page;default=1"`
 	PerPage  int     `in:"query=per_page;default=20"`
 	IsMember bool    `in:"query=is_member"`
+	Search   *string `in:"query=search;omitempty"`
 }
 
 func ListUsers(rw http.ResponseWriter, r *http.Request) {

core/directive.go

@@ -17,6 +17,7 @@ func init() {
 	RegisterDirective("default", &DirectiveDefault{})
 	RegisterDirective("nonzero", &DirectiveNonzero{})
 	registerDirective("path", defaultPathDirective)
+	registerDirective("omitempty", &DirectiveOmitEmpty{})
 
 	// decoder is a special executor which does nothing, but is an indicator of
 	// overriding the decoder for a specific field.

core/formencoder.go

@@ -1,12 +1,20 @@
 package core
 
-import "github.com/ggicci/httpin/internal"
+import (
+	"github.com/ggicci/httpin/internal"
+)
 
 type FormEncoder struct {
 	Setter func(key string, value []string) // form value setter
 }
 
 func (e *FormEncoder) Execute(rtm *DirectiveRuntime) error {
+	if rtm.Value.IsZero() {
+		if rtm.Resolver.GetDirective("omitempty") != nil {
+			return nil
+		}
+	}
+
 	if rtm.IsFieldSet() {
 		return nil // skip when already encoded by former directives
 	}

core/header_test.go

@@ -29,13 +29,15 @@ func TestDirectiveHeader_Decode(t *testing.T) {
 
 func TestDirectiveHeader_NewRequest(t *testing.T) {
 	type ApiQuery struct {
-		ApiUid   int    `in:"header=x-api-uid"`
-		ApiToken string `in:"header=X-Api-Token"`
+		ApiUid   int     `in:"header=x-api-uid;omitempty"`
+		ApiToken *string `in:"header=X-Api-Token;omitempty"`
 	}
 
+	t.Run("with all values", func(t *testing.T) {
+		tk := "some-secret-token"
 		query := &ApiQuery{
 			ApiUid:   91241844,
-		ApiToken: "some-secret-token",
+			ApiToken: &tk,
 		}
 
 		co, err := New(ApiQuery{})
@@ -48,4 +50,26 @@ func TestDirectiveHeader_NewRequest(t *testing.T) {
 		expected.Header.Set("x-api-uid", "91241844")
 		expected.Header.Set("X-Api-Token", "some-secret-token")
 		assert.Equal(t, expected, req)
+	})
+
+	t.Run("with empty value", func(t *testing.T) {
+		query := &ApiQuery{
+			ApiUid:   0,
+			ApiToken: nil,
+		}
+
+		co, err := New(ApiQuery{})
+		assert.NoError(t, err)
+		req, err := co.NewRequest("POST", "/api", query)
+		assert.NoError(t, err)
+
+		expected, _ := http.NewRequest("POST", "/api", nil)
+		assert.Equal(t, expected, req)
+
+		_, ok := req.Header["X-Api-Uid"]
+		assert.False(t, ok)
+
+		_, ok = req.Header["X-Api-Token"]
+		assert.False(t, ok)
+	})
 }

core/omitempty.go

@@ -0,0 +1,17 @@
+// directive: "omitempty"
+// https://ggicci.github.io/httpin/directives/omitempty
+
+package core
+
+// DirectiveOmitEmpty is used with the DirectiveQuery, DirectiveForm, and DirectiveHeader to indicate that the field
+// should be omitted when the value is empty.
+// It does not have any affect when used by itself
+type DirectiveOmitEmpty struct{}
+
+func (*DirectiveOmitEmpty) Decode(_ *DirectiveRuntime) error {
+	return nil
+}
+
+func (*DirectiveOmitEmpty) Encode(_ *DirectiveRuntime) error {
+	return nil
+}

core/query_test.go

@@ -33,7 +33,7 @@ func TestDirectiveQuery_Decode(t *testing.T) {
 func TestDirectiveQuery_NewRequest(t *testing.T) {
 	type SearchQuery struct {
 		Name    string  `in:"query=name"`
-		Age     int     `in:"query=age"`
+		Age     int     `in:"query=age;omitempty"`
 		Enabled bool    `in:"query=enabled"`
 		Price   float64 `in:"query=price"`
 
@@ -41,8 +41,10 @@ func TestDirectiveQuery_NewRequest(t *testing.T) {
 		AgeList  []int    `in:"query=age_list[]"`
 
 		NamePointer *string `in:"query=name_pointer"`
-		AgePointer  *int    `in:"query=age_pointer"`
+		AgePointer  *int    `in:"query=age_pointer;omitempty"`
 	}
+
+	t.Run("with all values", func(t *testing.T) {
 		query := &SearchQuery{
 			Name:     "cupcake",
 			Age:      12,
@@ -77,6 +79,22 @@ func TestDirectiveQuery_NewRequest(t *testing.T) {
 		expectedQuery.Set("age_pointer", "19")                // query.PointerAge
 		expected.URL.RawQuery = expectedQuery.Encode()
 		assert.Equal(t, expected, req)
+	})
+
+	t.Run("with empty values", func(t *testing.T) {
+		query := &SearchQuery{}
+
+		co, err := New(SearchQuery{})
+		assert.NoError(t, err)
+		req, err := co.NewRequest("GET", "/pets", query)
+		assert.NoError(t, err)
+
+		assert.True(t, req.URL.Query().Has("name"))
+		assert.False(t, req.URL.Query().Has("age"))
+
+		assert.True(t, req.URL.Query().Has("name_pointer"))
+		assert.False(t, req.URL.Query().Has("age_pointer"))
+	})
 }
 
 type Location struct {