diff --git a/pkg/progress/json_test.go b/pkg/progress/json_test.go
new file mode 100644
index 000000000..f77702ec7
--- /dev/null
+++ b/pkg/progress/json_test.go
@@ -0,0 +1,87 @@
+/*
+   Copyright 2024 Docker Compose CLI authors
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package progress
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"testing"
+
+	"gotest.tools/v3/assert"
+)
+
+func TestJsonWriter_Event(t *testing.T) {
+	var out bytes.Buffer
+	w := &jsonWriter{
+		out:    &out,
+		done:   make(chan bool),
+		dryRun: true,
+	}
+
+	event := Event{
+		ID:         "service1",
+		ParentID:   "project",
+		Text:       "Creating",
+		StatusText: "Working",
+		Current:    50,
+		Total:      100,
+		Percent:    50,
+	}
+	w.Event(event)
+
+	var msg jsonMessage
+	err := json.Unmarshal(out.Bytes(), &msg)
+	assert.NilError(t, err)
+
+	assert.Equal(t, true, msg.DryRun)
+	assert.Equal(t, false, msg.Tail)
+	assert.Equal(t, "service1", msg.ID)
+	assert.Equal(t, "project", msg.ParentID)
+	assert.Equal(t, "Creating", msg.Text)
+	assert.Equal(t, "Working", msg.Status)
+	assert.Equal(t, int64(50), msg.Current)
+	assert.Equal(t, int64(100), msg.Total)
+	assert.Equal(t, 50, msg.Percent)
+}
+
+func TestJsonWriter_TailMsgf(t *testing.T) {
+	var out bytes.Buffer
+	w := &jsonWriter{
+		out:    &out,
+		done:   make(chan bool),
+		dryRun: false,
+	}
+
+	go func() {
+		_ = w.Start(context.Background())
+	}()
+
+	w.TailMsgf("hello %s", "world")
+
+	w.Stop()
+
+	var msg jsonMessage
+	err := json.Unmarshal(out.Bytes(), &msg)
+	assert.NilError(t, err)
+
+	assert.Equal(t, false, msg.DryRun)
+	assert.Equal(t, true, msg.Tail)
+	assert.Equal(t, "hello world", msg.Text)
+	assert.Equal(t, "", msg.ID)
+	assert.Equal(t, "", msg.Status)
+}
\ No newline at end of file