fix(chat): restore download media JSON result

CHANGELOG.md

@@ -6,6 +6,10 @@ The format is inspired by [Keep a Changelog](https://keepachangelog.com/) and th
 
 ## [Unreleased]
 
+### Fixed
+
+- **Chat media download JSON compatibility** — `dws chat message download-media --format json` once again returns a clean `{success, downloadUrl, output}` result after the file is saved, preserving the temporary URL and resolved local path without progress text corrupting JSON stdout.
+
 ## [1.0.56-beta.3] - 2026-08-03
 
 This beta adds PRs #846 and #851 on top of v1.0.56-beta.2. It adds a

internal/helpers/chat.go

@@ -3434,6 +3434,7 @@ flow-status 取值：1=处理中(PROCESSING)，2=输入中(INPUTTING)，3=完成
 			conversationID := mustGetFlag(cmd, "open-conversation-id")
 			messageID := mustGetFlag(cmd, "message-id")
 			outputPath := mustGetFlag(cmd, "output")
+			jsonMode := deps.Caller.Format() == "json"
 
 			switch resourceType {
 			case "mediaId":
@@ -3455,7 +3456,9 @@ flow-status 取值：1=处理中(PROCESSING)，2=输入中(INPUTTING)，3=完成
 			ctx := context.Background()
 
 			// Step 1: 获取下载 URL
-			deps.Out.PrintInfo("[1/2] 获取资源下载链接...")
+			if !jsonMode {
+				deps.Out.PrintInfo("[1/2] 获取资源下载链接...")
+			}
 			text, err := callMCPToolReturnTextOnServer(ctx, "im", "get_resource_download_url", map[string]any{
 				"resourceType":       resourceType,
 				"resourceId":         resourceID,
@@ -3488,11 +3491,20 @@ flow-status 取值：1=处理中(PROCESSING)，2=输入中(INPUTTING)，3=完成
 			}
 
 			// Step 2: HTTP GET 下载文件
-			deps.Out.PrintInfo(fmt.Sprintf("[2/2] 下载资源到 %s ...", outputPath))
+			if !jsonMode {
+				deps.Out.PrintInfo(fmt.Sprintf("[2/2] 下载资源到 %s ...", outputPath))
+			}
 			if err := httpGetFile(ctx, resourceURL, dlHeaders, outputPath); err != nil {
 				return err
 			}
 
+			if jsonMode {
+				return deps.Out.PrintJSONUnescaped(map[string]any{
+					"success":     true,
+					"downloadUrl": resourceURL,
+					"output":      outputPath,
+				})
+			}
 			deps.Out.PrintInfo(fmt.Sprintf("下载完成: %s", outputPath))
 			return nil
 		},

internal/helpers/chat_download_media_test.go

@@ -0,0 +1,95 @@
+// Copyright 2026 Alibaba Group
+// 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 helpers
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestChatDownloadMediaJSONPreservesLegacyResult(t *testing.T) {
+	previousDeps, previousArgs := deps, os.Args
+	previousHTTPGetFile := httpGetFile
+	os.Args = []string{"dws", "chat"}
+	t.Cleanup(func() {
+		deps = previousDeps
+		os.Args = previousArgs
+		httpGetFile = previousHTTPGetFile
+	})
+
+	const downloadURL = "https://download.example.test/photo.jpg?token=one&part=two"
+	caller := &scriptedToolCaller{
+		format: "json",
+		steps: []scriptedToolStep{{
+			text: `{"resourceUrl":"` + downloadURL + `"}`,
+		}},
+	}
+	InitDeps(caller)
+	var stdout bytes.Buffer
+	deps.Out = &Formatter{w: &stdout, errW: io.Discard}
+
+	outputDir := t.TempDir()
+	wantOutput := filepath.Join(outputDir, "photo.jpg")
+	httpGetFile = func(_ context.Context, gotURL string, _ map[string]string, gotOutput string) error {
+		if gotURL != downloadURL {
+			t.Fatalf("download URL = %q, want %q", gotURL, downloadURL)
+		}
+		if gotOutput != wantOutput {
+			t.Fatalf("download output = %q, want %q", gotOutput, wantOutput)
+		}
+		return nil
+	}
+
+	root := newChatCommand()
+	installExampleGlobalFlags(root)
+	root.SilenceErrors = true
+	root.SilenceUsage = true
+	root.SetOut(io.Discard)
+	root.SetErr(io.Discard)
+	root.SetArgs([]string{
+		"message", "download-media",
+		"--type=mediaId",
+		"--resource-id=resource",
+		"--message-id=message",
+		"--open-conversation-id=conversation",
+		"--output=" + outputDir,
+	})
+	if err := root.ExecuteContext(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+
+	var got struct {
+		Success     bool   `json:"success"`
+		DownloadURL string `json:"downloadUrl"`
+		Output      string `json:"output"`
+	}
+	if err := json.Unmarshal(stdout.Bytes(), &got); err != nil {
+		t.Fatalf("stdout is not JSON: %v\n%s", err, stdout.String())
+	}
+	if !got.Success || got.DownloadURL != downloadURL || got.Output != wantOutput {
+		t.Fatalf("result = %#v, want success=true downloadUrl=%q output=%q", got, downloadURL, wantOutput)
+	}
+	if strings.Contains(stdout.String(), "[INFO]") {
+		t.Fatalf("JSON stdout contains progress text: %s", stdout.String())
+	}
+	if !strings.Contains(stdout.String(), "?token=one&part=two") {
+		t.Fatalf("downloadUrl was escaped or changed: %s", stdout.String())
+	}
+}