fix: json output for empty array

go.sum

@@ -65,6 +65,7 @@ github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZN
 github.com/russross/blackfriday v1.5.2/go.mod h1:JO/DiYxRf+HjHt06OyowR9PTA263kcR/rfWxYHBV53g=
 github.com/scaleway/scaleway-sdk-go v1.0.0-beta.6.0.20200511151306-5e35a6b50424 h1:daVeC8IxL9EA3ASo38uwQm2nGcprn0L0XMb8Sj5DL4Y=
 github.com/scaleway/scaleway-sdk-go v1.0.0-beta.6.0.20200511151306-5e35a6b50424/go.mod h1:CJJ5VAbozOl0yEw7nHB9+7BXTJbIn6h7W+f6Gau5IP8=
+github.com/sergi/go-diff v1.0.0 h1:Kpca3qRNrduNnOQeazBd0ysaKrUJiIuISHxogkT9RPQ=
 github.com/sergi/go-diff v1.0.0/go.mod h1:0CfEIISq7TuYL3j771MWULgwwjU+GofnZX9QAmXWZgo=
 github.com/spf13/afero v1.1.2/go.mod h1:j4pytiNVoe2o6bmDsKpLACNPDBIoEAkihy7loJ1B0CQ=
 github.com/spf13/cast v1.3.0/go.mod h1:Qx5cxh0v+4UWYiBimWS+eyWzqEqokIECu5etghLkUJE=

internal/core/bootstrap_test.go

@@ -5,6 +5,7 @@ import (
 	"reflect"
 	"testing"
 
+	"github.com/alecthomas/assert"
 	"github.com/scaleway/scaleway-cli/internal/args"
 	"github.com/scaleway/scaleway-cli/internal/interactive"
 )
@@ -44,7 +45,7 @@ func TestInterruptError(t *testing.T) {
 		Cmd:             "scw test code error",
 		Check:           TestCheckExitCode(99),
 	}))
-	t.Run("emtpy-error", Test(&TestConfig{
+	t.Run("empty-error", Test(&TestConfig{
 		Commands: NewCommands(
 			&Command{
 				Namespace: "test",
@@ -64,7 +65,7 @@ func TestInterruptError(t *testing.T) {
 			TestCheckStderrGolden(),
 		),
 	}))
-	t.Run("emtpy-error-json", Test(&TestConfig{
+	t.Run("empty-error-json", Test(&TestConfig{
 		Commands: NewCommands(
 			&Command{
 				Namespace: "test",
@@ -84,7 +85,7 @@ func TestInterruptError(t *testing.T) {
 			TestCheckStderrGolden(),
 		),
 	}))
-	t.Run("emtpy-success", Test(&TestConfig{
+	t.Run("empty-success", Test(&TestConfig{
 		Commands: NewCommands(
 			&Command{
 				Namespace: "test",
@@ -107,7 +108,7 @@ func TestInterruptError(t *testing.T) {
 		Cmd:             "scw test empty success",
 		Check:           TestCheckStdoutGolden(),
 	}))
-	t.Run("emtpy-success-json", Test(&TestConfig{
+	t.Run("empty-success-json", Test(&TestConfig{
 		Commands: NewCommands(
 			&Command{
 				Namespace: "test",
@@ -131,4 +132,22 @@ func TestInterruptError(t *testing.T) {
 		Cmd:             "scw -o json test empty success",
 		Check:           TestCheckStdoutGolden(),
 	}))
+	t.Run("empty-list-json", Test(&TestConfig{
+		Commands: NewCommands(
+			&Command{
+				Namespace: "test",
+				Resource:  "empty",
+				Verb:      "success",
+				ArgsType:  reflect.TypeOf(args.RawArgs{}),
+				Run: func(ctx context.Context, argsI interface{}) (i interface{}, e error) {
+					return []int(nil), nil
+				},
+				AllowAnonymousClient: true,
+			},
+		),
+		Cmd: "scw -o json test empty success",
+		Check: func(t *testing.T, ctx *CheckFuncCtx) {
+			assert.Equal(t, "[]\n", string(ctx.Stdout))
+		},
+	}))
 }

internal/printer/json.go

@@ -3,6 +3,7 @@ package printer
 import (
 	"encoding/json"
 	"io"
+	"reflect"
 
 	"github.com/scaleway/scaleway-cli/internal/human"
 )
@@ -34,5 +35,9 @@ func (o *jsonPrinter) Print(data interface{}, opt *human.MarshalOpt) error {
 		}
 	}
 
+	if reflect.TypeOf(data).Kind() == reflect.Slice && reflect.ValueOf(data).IsNil() {
+		_, err := o.Writer.Write([]byte("[]\n"))
+		return err
+	}
 	return json.NewEncoder(o.Writer).Encode(data)
 }