Support for List of Enums in Headers (#4166)

Adds support for list of enums in headers.

private/model/api/shape.go

@@ -567,6 +567,8 @@ func (ref *ShapeRef) GoTags(toplevel bool, isRequired bool) string {
 	}
 	if ref.Shape.IsEnum() {
 		tags = append(tags, ShapeTag{"enum", ref.ShapeName})
+	} else if ref.Shape.Type == "list" && ref.Shape.MemberRef.Shape.IsEnum() {
+		tags = append(tags, ShapeTag{"enum", ref.Shape.MemberRef.ShapeName})
 	}
 
 	if toplevel {

private/protocol/rest/build.go

@@ -276,6 +276,25 @@ func convertType(v reflect.Value, tag reflect.StructTag) (str string, err error)
 			value = base64.StdEncoding.EncodeToString([]byte(value))
 		}
 		str = value
+	case []*string:
+		if tag.Get("location") != "header" || tag.Get("enum") == "" {
+			return "", fmt.Errorf("%T is only supported with location header and enum shapes", value)
+		}
+		buff := &bytes.Buffer{}
+		for i, sv := range value {
+			if sv == nil || len(*sv) == 0 {
+				continue
+			}
+			if i != 0 {
+				buff.WriteRune(',')
+			}
+			item := *sv
+			if strings.Index(item, `,`) != -1 || strings.Index(item, `"`) != -1 {
+				item = strconv.Quote(item)
+			}
+			buff.WriteString(item)
+		}
+		str = string(buff.Bytes())
 	case []byte:
 		str = base64.StdEncoding.EncodeToString(value)
 	case bool:

private/protocol/rest/build_test.go

@@ -3,6 +3,7 @@ package rest
 import (
 	"net/http"
 	"net/url"
+	"reflect"
 	"testing"
 
 	"github.com/aws/aws-sdk-go/aws"
@@ -61,3 +62,116 @@ func TestMarshalPath(t *testing.T) {
 	}
 
 }
+
+func TestListOfEnums(t *testing.T) {
+	cases := []struct {
+		Input    interface{}
+		Expected http.Header
+		WantErr  bool
+	}{
+		{
+			Input: func() interface{} {
+				type v struct {
+					List []*string `type:"list" location:"header" locationName:"x-amz-test-header"`
+				}
+				return &v{
+					List: []*string{aws.String("foo")},
+				}
+			}(),
+			WantErr: true,
+		},
+		{
+			Input: func() interface{} {
+				type v struct {
+					List []*string `type:"list" location:"uri" locationName:"someList"`
+				}
+				return &v{
+					List: []*string{aws.String("foo")},
+				}
+			}(),
+			WantErr: true,
+		},
+		{
+			Input: func() interface{} {
+				type v struct {
+					List map[string][]*string `type:"map" location:"headers" locationName:"x-amz-metadata"`
+				}
+				return &v{
+					List: map[string][]*string{
+						"foo": {aws.String("foo")},
+					},
+				}
+			}(),
+			WantErr: true,
+		},
+		{
+			Input: func() interface{} {
+				type v struct {
+					List []*string `type:"list" location:"header" locationName:"x-amz-test-header" enum:"FooBar"`
+				}
+				return &v{
+					List: []*string{aws.String("foo")},
+				}
+			}(),
+			Expected: http.Header{
+				"X-Amz-Test-Header": {"foo"},
+			},
+		},
+		{
+			Input: func() interface{} {
+				type v struct {
+					List []*string `type:"list" location:"header" locationName:"x-amz-test-header" enum:"FooBar"`
+				}
+				return &v{
+					List: []*string{aws.String("foo"), nil, aws.String(""), nil, aws.String("bar")},
+				}
+			}(),
+			Expected: http.Header{
+				"X-Amz-Test-Header": {"foo,bar"},
+			},
+		},
+		{
+			Input: func() interface{} {
+				type v struct {
+					List []*string `type:"list" location:"header" locationName:"x-amz-test-header" enum:"FooBar"`
+				}
+				return &v{
+					List: []*string{aws.String("f,o,o"), nil, aws.String(""), nil, aws.String(`"bar"`)},
+				}
+			}(),
+			Expected: http.Header{
+				"X-Amz-Test-Header": {`"f,o,o","\"bar\""`},
+			},
+		},
+	}
+
+	for i, tt := range cases {
+		req := &request.Request{
+			HTTPRequest: &http.Request{
+				URL: func() *url.URL {
+					u, err := url.Parse("https://foo.amazonaws.com")
+					if err != nil {
+						panic(err)
+					}
+					return u
+				}(),
+				Header: map[string][]string{},
+			},
+			Params: tt.Input,
+		}
+
+		Build(req)
+
+		if (req.Error != nil) != (tt.WantErr) {
+			t.Fatalf("(%d) WantErr(%t) got %v", i, tt.WantErr, req.Error)
+		}
+
+		if tt.WantErr {
+			continue
+		}
+
+		if e, a := tt.Expected, req.HTTPRequest.Header; !reflect.DeepEqual(e, a) {
+			t.Errorf("(%d) expect %v, got %v", i, e, a)
+		}
+	}
+}