feat(autocli): add json file parsing support

client/v2/autocli/flag/message_json.go

@@ -3,6 +3,9 @@ package flag
 import (
 	"context"
 	"fmt"
+	"io"
+	"os"
+	"regexp"
 
 	"google.golang.org/protobuf/encoding/protojson"
 	"google.golang.org/protobuf/proto"
@@ -11,6 +14,8 @@ import (
 	"cosmossdk.io/client/v2/internal/util"
 )
 
+var isJSONFileRegex = regexp.MustCompile(`\.json$`)
+
 type jsonMessageFlagType struct {
 	messageDesc protoreflect.MessageDescriptor
 }
@@ -55,7 +60,20 @@ func (j *jsonMessageFlagValue) String() string {
 
 func (j *jsonMessageFlagValue) Set(s string) error {
 	j.message = j.messageType.New().Interface()
-	return j.jsonUnmarshalOptions.Unmarshal([]byte(s), j.message)
+	var messageBytes []byte
+	if isJSONFileRegex.MatchString(s) {
+		jsonFile, err := os.Open(s)
+		if err != nil {
+			return err
+		}
+		messageBytes, err = io.ReadAll(jsonFile)
+		if err != nil {
+			return err
+		}
+	} else {
+		messageBytes = []byte(s)
+	}
+	return j.jsonUnmarshalOptions.Unmarshal(messageBytes, j.message)
 }
 
 func (j *jsonMessageFlagValue) Type() string {

client/v2/autocli/query_test.go

@@ -143,6 +143,25 @@ func TestEverything(t *testing.T) {
 	assert.DeepEqual(t, conn.lastRequest, conn.lastResponse.(*testpb.EchoResponse).Request, protocmp.Transform())
 }
 
+func TestJSONParsing(t *testing.T) {
+	conn := testExecCommon(t, buildModuleQueryCommand,
+		"echo",
+		"1", "abc", `{"denom":"foo","amount":"1"}`,
+		"--some-messages", `{"bar":"baz"}`,
+		"-u", "27", // shorthand
+	)
+	assert.DeepEqual(t, conn.lastRequest, conn.lastResponse.(*testpb.EchoResponse).Request, protocmp.Transform())
+
+	conn = testExecCommon(t, buildModuleQueryCommand,
+		"echo",
+		"1", "abc", `{"denom":"foo","amount":"1"}`,
+		"--some-messages", "testdata/some_message.json",
+		"-u", "27", // shorthand
+	)
+	assert.DeepEqual(t, conn.lastRequest, conn.lastResponse.(*testpb.EchoResponse).Request, protocmp.Transform())
+
+}
+
 func TestOptions(t *testing.T) {
 	conn := testExecCommon(t, buildModuleQueryCommand,
 		"echo",

client/v2/autocli/testdata/some_message.json

@@ -0,0 +1 @@
+{"bar":"baz"}