go-bare: Omit struct fields with a field tag of "-". v2 PROPOSED

Adnan Maolood: 1
 Omit struct fields with a field tag of "-".

 4 files changed, 45 insertions(+), 0 deletions(-)

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[PATCH go-bare v2] Omit struct fields with a field tag of "-". Export this patch

---
 marshal.go        | 11 +++++++++++
 marshal_test.go   | 13 +++++++++++++
 unmarshal.go      |  6 ++++++
 unmarshal_test.go | 15 +++++++++++++++
 4 files changed, 45 insertions(+)

diff --git a/marshal.go b/marshal.go
index 55acce7..031c90e 100644
--- a/marshal.go
+++ b/marshal.go
@@ -26,6 +26,11 @@ var encoderBufferPool = sync.Pool{
 //
 // Go "int" and "uint" types are represented as BARE u32 and i32 types
 // respectively, for message compatibility with both 32-bit and 64-bit systems.
+//
+// The encoding of each struct field can be customized by the format string
+// stored under the "bare" key in the struct field's tag.
+//
+// As a special case, if the field tag is "-", the field is always omitted.
 func Marshal(val interface{}) ([]byte, error) {
 	// reuse buffers from previous serializations
 	b := encoderBufferPool.Get().(*bytes.Buffer)
@@ -127,11 +132,17 @@ func encodeStruct(t reflect.Type) encodeFunc {
 	encoders := make([]encodeFunc, n)
 	for i := 0; i < n; i++ {
 		field := t.Field(i)
+		if field.Tag.Get("bare") == "-" {
+			continue
+		}
 		encoders[i] = getEncoder(field.Type)
 	}
 
 	return func(w *Writer, v reflect.Value) error {
 		for i := 0; i < n; i++ {
+			if encoders[i] == nil {
+				continue
+			}
 			err := encoders[i](w, v.Field(i))
 			if err != nil {
 				return err
diff --git a/marshal_test.go b/marshal_test.go
index 093100a..130d378 100644
--- a/marshal_test.go
+++ b/marshal_test.go
@@ -162,6 +162,19 @@ func TestMarshalStruct(t *testing.T) {
 	assert.Equal(t, reference, data)
 }
 
+func TestMarshalOmittedFields(t *testing.T) {
+	type Coordinates struct {
+		X uint
+		Y uint
+		Z uint `bare:"-"`
+	}
+	coords := Coordinates{1, 2, 3}
+	reference := []byte{0x01, 0x02}
+	data, err := Marshal(&coords)
+	assert.Nil(t, err)
+	assert.Equal(t, reference, data)
+}
+
 func TestMarshalArray(t *testing.T) {
 	val := [4]uint8{0x11, 0x22, 0x33, 0x44}
 	reference := []byte{0x11, 0x22, 0x33, 0x44}
diff --git a/unmarshal.go b/unmarshal.go
index 85fe5ef..7ba4b56 100644
--- a/unmarshal.go
+++ b/unmarshal.go
@@ -125,11 +125,17 @@ func decodeStruct(t reflect.Type) decodeFunc {
 	decoders := make([]decodeFunc, n)
 	for i := 0; i < n; i++ {
 		field := t.Field(i)
+		if field.Tag.Get("bare") == "-" {
+			continue
+		}
 		decoders[i] = getDecoder(field.Type)
 	}
 
 	return func(r *Reader, v reflect.Value) error {
 		for i := 0; i < n; i++ {
+			if decoders[i] == nil {
+				continue
+			}
 			err := decoders[i](r, v.Field(i))
 			if err != nil {
 				return err
diff --git a/unmarshal_test.go b/unmarshal_test.go
index 33093e2..cc05ddb 100644
--- a/unmarshal_test.go
+++ b/unmarshal_test.go
@@ -135,6 +135,21 @@ func TestUnmarshalStruct(t *testing.T) {
 	assert.Equal(t, uint(3), coords.Z, "Expected Unmarshal to read {1, 2, 3}")
 }
 
+func TestUnmarshalOmittedFields(t *testing.T) {
+	type Coordinates struct {
+		X uint
+		Y uint
+		Z uint `bare:"-"`
+	}
+	payload := []byte{0x01, 0x02}
+	var coords Coordinates
+	err := Unmarshal(payload, &coords)
+	assert.Nil(t, err, "Expected Unmarshal to return without error")
+	assert.Equal(t, uint(1), coords.X, "Expected Unmarshal to read {1, 2}")
+	assert.Equal(t, uint(2), coords.Y, "Expected Unmarshal to read {1, 2}")
+	assert.Equal(t, uint(0), coords.Z, "Expected Unmarshal to ignore field")
+}
+
 func TestUnmarshalArray(t *testing.T) {
 	var val [4]uint8
 	err := Unmarshal([]byte{0x11, 0x22, 0x33, 0x44}, &val)
-- 
2.29.2

Drew DeVault

3 months ago

Thanks!

To git@git.sr.ht:~sircmpwn/go-bare
   f56bf90..  master -> master

builds.sr.ht

3 months ago

go-bare/patches/.build.yml: SUCCESS in 30s

[Omit struct fields with a field tag of "-".][0] v2 from [Adnan Maolood][1]

[0]: https://lists.sr.ht/~sircmpwn/public-inbox/patches/15100
[1]: mailto:me@adnano.co

✓ #344591 SUCCESS go-bare/patches/.build.yml https://builds.sr.ht/~sircmpwn/job/344591