Add support for --bytes-as-base64 (#611)

This allows entering bytes as a base64-encoded string, using the standard
encoding.

Co-authored-by: ktr <ktr@syfm.me>

README.md

@@ -279,6 +279,12 @@ data (TYPE_BYTES) => \u65e5\u672c\u8a9e
 }
 ```
 
+Or add the flag `--bytes-as-base64` to pass bytes as a base64-encoded string
+```
+> call UnaryBytes --bytes-as-base64
+data (TYPE_BYTES) => SGVsbG8gV29ybGQh
+```
+
 Or add the flag `--bytes-from-file` to read bytes from the provided relative path
 ```
 > call UnaryBytes --bytes-from-file

e2e/testdata/fixtures/teste2e_repl-call_--help.golden

@@ -2,7 +2,8 @@ usage: call <method name>
 
 Options:
       --add-repeated-manually   prompt asks whether to add a value if it encountered to a repeated field
-      --bytes-from-file         interpret TYPE_BYTES input as a relative path to a file
+      --bytes-as-base64         interpret TYPE_BYTES input as base64-encoded string (mutually exclusive with --bytes-from-file)
+      --bytes-from-file         interpret TYPE_BYTES input as a relative path to a file (mutually exclusive with --bytes-as-base64)
       --dig-manually            prompt asks whether to dig down if it encountered to a message field
       --emit-defaults           render fields with default values
       --enrich                  enrich response output includes header, message, trailer and status

fill/filler.go

@@ -22,6 +22,8 @@ type Filler interface {
 type InteractiveFillerOpts struct {
 	// DigManually is true, Fill asks whether to dig down if it encountered to a message field.
 	DigManually,
+	// BytesAsBase64 is true, Fill will interpret input as base64-encoded string
+	BytesAsBase64,
 	// BytesFromFile is true, Fill will read the contents of the file from the provided relative path.
 	BytesFromFile,
 	// AddRepeatedManually is true, Fill asks whether to add a repeated field value

fill/proto/interactive_filler.go

@@ -1,6 +1,7 @@
 package proto
 
 import (
+	"encoding/base64"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -201,7 +202,12 @@ func (r *resolver) resolveField(f *desc.FieldDescriptor) error {
 		// So, we need to call strconv.Unquote to interpret backslashes as an escape sequence.
 		case descriptorpb.FieldDescriptorProto_TYPE_BYTES:
 			converter = func(v string) (interface{}, error) {
-				if r.opts.BytesFromFile {
+				if r.opts.BytesAsBase64 {
+					b, err := base64.StdEncoding.DecodeString(v)
+					if err == nil {
+						return b, nil
+					}
+				} else if r.opts.BytesFromFile {
 					b, err := ioutil.ReadFile(v)
 					if err == nil {
 						return b, nil

repl/commands.go

@@ -155,15 +155,16 @@ func (c *showCommand) Run(w io.Writer, args []string) error {
 }
 
 type callCommand struct {
-	enrich, digManually, bytesFromFile, emitDefaults, repeatCall, addRepeatedManually bool
+	enrich, digManually, bytesAsBase64, bytesFromFile, emitDefaults, repeatCall, addRepeatedManually bool
 }
 
 func (c *callCommand) FlagSet() (*pflag.FlagSet, bool) {
 	fs := pflag.NewFlagSet("call", pflag.ContinueOnError)
 	fs.Usage = func() {} // Disable help output when an error occurred.
 	fs.BoolVar(&c.enrich, "enrich", false, "enrich response output includes header, message, trailer and status")
 	fs.BoolVar(&c.digManually, "dig-manually", false, "prompt asks whether to dig down if it encountered to a message field")
-	fs.BoolVar(&c.bytesFromFile, "bytes-from-file", false, "interpret TYPE_BYTES input as a relative path to a file")
+	fs.BoolVar(&c.bytesAsBase64, "bytes-as-base64", false, "interpret TYPE_BYTES input as base64-encoded string (mutually exclusive with --bytes-from-file)")
+	fs.BoolVar(&c.bytesFromFile, "bytes-from-file", false, "interpret TYPE_BYTES input as a relative path to a file (mutually exclusive with --bytes-as-base64)")
 	fs.BoolVar(&c.emitDefaults, "emit-defaults", false, "render fields with default values")
 	fs.BoolVarP(&c.repeatCall, "repeat", "r", false, "repeat previous unary or server streaming request (if exists)")
 	fs.BoolVar(&c.addRepeatedManually, "add-repeated-manually", false, "prompt asks whether to add a value if it encountered to a repeated field")
@@ -199,9 +200,15 @@ func (c *callCommand) Run(w io.Writer, args []string) error {
 		},
 	)
 
+	// Ensure bytesAsBase64 and bytesFromFile are not both set
+	// pflag doesn't suppport mutually exclusive flags (https://github.com/spf13/pflag/issues/270)
+	if c.bytesAsBase64 && c.bytesFromFile {
+		return errors.New("only one of --bytes-as-base64 or --bytes-from-file can be specified")
+	}
+
 	// here we create the request context
 	// we also add the call command flags here
-	err := usecase.CallRPCInteractively(context.Background(), w, args[0], c.digManually, c.bytesFromFile, c.repeatCall, c.addRepeatedManually)
+	err := usecase.CallRPCInteractively(context.Background(), w, args[0], c.digManually, c.bytesAsBase64, c.bytesFromFile, c.repeatCall, c.addRepeatedManually)
 	if errors.Is(err, io.EOF) {
 		return errors.New("inputting canceled")
 	}

usecase/call_rpc.go

@@ -478,15 +478,16 @@ func (f *interactiveFiller) Fill(v interface{}) error {
 	return f.fillFunc(v)
 }
 
-func CallRPCInteractively(ctx context.Context, w io.Writer, rpcName string, digManually, bytesFromFile, rerunPrevious, addRepeatedManually bool) error {
-	return dm.CallRPCInteractively(ctx, w, rpcName, digManually, bytesFromFile, rerunPrevious, addRepeatedManually)
+func CallRPCInteractively(ctx context.Context, w io.Writer, rpcName string, digManually, bytesAsBase64, bytesFromFile, rerunPrevious, addRepeatedManually bool) error {
+	return dm.CallRPCInteractively(ctx, w, rpcName, digManually, bytesAsBase64, bytesFromFile, rerunPrevious, addRepeatedManually)
 }
 
-func (m *dependencyManager) CallRPCInteractively(ctx context.Context, w io.Writer, rpcName string, digManually, bytesFromFile, rerunPrevious, addRepeatedManually bool) error {
+func (m *dependencyManager) CallRPCInteractively(ctx context.Context, w io.Writer, rpcName string, digManually, bytesAsBase64, bytesFromFile, rerunPrevious, addRepeatedManually bool) error {
 	return m.CallRPC(ctx, w, rpcName, rerunPrevious, &interactiveFiller{
 		fillFunc: func(v interface{}) error {
 			return m.interactiveFiller.Fill(v, fill.InteractiveFillerOpts{
 				DigManually:         digManually,
+				BytesAsBase64:       bytesAsBase64,
 				BytesFromFile:       bytesFromFile,
 				AddRepeatedManually: addRepeatedManually,
 			})