Fix for #2383 (#3004)

Author: Bogdan Dinu

.changelog/adfe779a-b5b4-44bd-8e23-5cdb4db5aef8.json

@@ -0,0 +1,10 @@
+{
+  "id": "adfe779a-b5b4-44bd-8e23-5cdb4db5aef8",
+  "type": "bugfix",
+  "collapse": false,
+  "description": "DynamoDB AttributeValue's MarshallMap() Does Not Support time.Time Correctly #2383",
+  "modules": [
+    "feature/dynamodb",
+    "feature/dynamodbstreams"
+  ]
+}

feature/dynamodb/attributevalue/encode.go

@@ -399,6 +399,9 @@ type EncoderOptions struct {
 	// NULL attribute values returned from the standard marshaling routine will
 	// always respect omitempty regardless of this setting.
 	OmitNullAttributeValues bool
+
+	// When enabled, the encoder will omit empty time attribute values
+	OmitEmptyTime bool
 }
 
 // An Encoder provides marshaling Go value types to AttributeValues.
@@ -499,6 +502,11 @@ func (e *Encoder) encodeStruct(v reflect.Value, fieldTag tag) (types.AttributeVa
 	if v.Type().ConvertibleTo(timeType) {
 		var t time.Time
 		t = v.Convert(timeType).Interface().(time.Time)
+
+		if e.options.OmitEmptyTime && fieldTag.OmitEmpty && t.IsZero() {
+			return nil, nil
+		}
+
 		if fieldTag.AsUnixTime {
 			return UnixTime(t).MarshalDynamoDBAttributeValue()
 		}

feature/dynamodb/attributevalue/encode_test.go

@@ -830,3 +830,39 @@ func TestMarshalMap_keyTypes(t *testing.T) {
 		})
 	}
 }
+
+func TestEncodeEmptyTime(t *testing.T) {
+	type A struct {
+		Created time.Time `dynamodbav:"created,omitempty"`
+	}
+
+	a := A{Created: time.Time{}}
+
+	actual, err := MarshalWithOptions(a, func(o *EncoderOptions) {
+		o.OmitEmptyTime = true
+	})
+	if err != nil {
+		t.Errorf("expect nil, got %v", err)
+	}
+
+	expect := &types.AttributeValueMemberM{
+		Value: map[string]types.AttributeValue{},
+	}
+
+	if e, a := expect, actual; !reflect.DeepEqual(e, a) {
+		t.Errorf("expect %v, got %v", e, a)
+	}
+
+	actual2, err := MarshalMapWithOptions(a, func(o *EncoderOptions) {
+		o.OmitEmptyTime = true
+	})
+	if err != nil {
+		t.Errorf("expect nil, got %v", err)
+	}
+
+	expect2 := map[string]types.AttributeValue{}
+
+	if e, a := expect2, actual2; !reflect.DeepEqual(e, a) {
+		t.Errorf("expect %v, got %v", e, a)
+	}
+}

feature/dynamodbstreams/attributevalue/encode.go

@@ -399,6 +399,9 @@ type EncoderOptions struct {
 	// NULL attribute values returned from the standard marshaling routine will
 	// always respect omitempty regardless of this setting.
 	OmitNullAttributeValues bool
+
+	// When enabled, the encoder will omit empty time attribute values
+	OmitEmptyTime bool
 }
 
 // An Encoder provides marshaling Go value types to AttributeValues.
@@ -499,6 +502,11 @@ func (e *Encoder) encodeStruct(v reflect.Value, fieldTag tag) (types.AttributeVa
 	if v.Type().ConvertibleTo(timeType) {
 		var t time.Time
 		t = v.Convert(timeType).Interface().(time.Time)
+
+		if e.options.OmitEmptyTime && fieldTag.OmitEmpty && t.IsZero() {
+			return nil, nil
+		}
+
 		if fieldTag.AsUnixTime {
 			return UnixTime(t).MarshalDynamoDBStreamsAttributeValue()
 		}

feature/dynamodbstreams/attributevalue/encode_test.go

@@ -830,3 +830,39 @@ func TestMarshalMap_keyTypes(t *testing.T) {
 		})
 	}
 }
+
+func TestEncodeEmptyTime(t *testing.T) {
+	type A struct {
+		Created time.Time `dynamodbav:"created,omitempty"`
+	}
+
+	a := A{Created: time.Time{}}
+
+	actual, err := MarshalWithOptions(a, func(o *EncoderOptions) {
+		o.OmitEmptyTime = true
+	})
+	if err != nil {
+		t.Errorf("expect nil, got %v", err)
+	}
+
+	expect := &types.AttributeValueMemberM{
+		Value: map[string]types.AttributeValue{},
+	}
+
+	if e, a := expect, actual; !reflect.DeepEqual(e, a) {
+		t.Errorf("expect %v, got %v", e, a)
+	}
+
+	actual2, err := MarshalMapWithOptions(a, func(o *EncoderOptions) {
+		o.OmitEmptyTime = true
+	})
+	if err != nil {
+		t.Errorf("expect nil, got %v", err)
+	}
+
+	expect2 := map[string]types.AttributeValue{}
+
+	if e, a := expect2, actual2; !reflect.DeepEqual(e, a) {
+		t.Errorf("expect %v, got %v", e, a)
+	}
+}