fix(adk/filesystem): fix emptyStreamConcatErr when streaming execute command has no output (#790)

Author: hi-pender

.github/.commit-rules.json

@@ -14,6 +14,7 @@
   ],
   "allowedScopes": [
     "adk",
+    "adk/filesystem",
     "callbacks",
     "components",
     "compose",

.github/workflows/pr-check.yml

@@ -37,6 +37,7 @@ jobs:
         # https://golangci-lint.run/
         uses: golangci/golangci-lint-action@v9.2.0
         with:
+          version: v2.8.0
           args: --timeout 5m
 
   commit-msg-check:

adk/middlewares/filesystem/filesystem.go

@@ -407,20 +407,45 @@ func newStreamingExecuteTool(sb filesystem.StreamingShellBackend, desc *string)
 				}
 				sw.Close()
 			}()
+
+			var hasSentContent bool
+			var exitCode *int
+
 			for {
 				chunk, recvErr := result.Recv()
 				if recvErr == io.EOF {
 					break
 				}
 				if recvErr != nil {
 					sw.Send("", recvErr)
-					break
+					return
+				}
+
+				if chunk == nil {
+					continue
+				}
+				if chunk.ExitCode != nil {
+					exitCode = chunk.ExitCode
 				}
 
-				if str := convExecuteResponse(chunk); str != "" {
-					sw.Send(str, nil)
+				parts := make([]string, 0, 2)
+				if chunk.Output != "" {
+					parts = append(parts, chunk.Output)
+				}
+				if chunk.Truncated {
+					parts = append(parts, "[Output was truncated due to size limits]")
+				}
+				if len(parts) > 0 {
+					sw.Send(strings.Join(parts, "\n"), nil)
+					hasSentContent = true
 				}
 			}
+
+			if exitCode != nil && *exitCode != 0 {
+				sw.Send(fmt.Sprintf("\n[Command failed with exit code %d]", *exitCode), nil)
+			} else if !hasSentContent {
+				sw.Send("[Command executed successfully with no output]", nil)
+			}
 		}()
 
 		return sr, nil
@@ -436,8 +461,12 @@ func convExecuteResponse(response *filesystem.ExecuteResponse) string {
 		parts = append(parts, fmt.Sprintf("[Command failed with exit code %d]", *response.ExitCode))
 	}
 	if response.Truncated {
-		parts = append(parts, fmt.Sprintf("[Output was truncated due to size limits]"))
+		parts = append(parts, "[Output was truncated due to size limits]")
 	}
 
-	return strings.Join(parts, "\n")
+	result := strings.Join(parts, "\n")
+	if result == "" && (response.ExitCode == nil || *response.ExitCode == 0) {
+		return "[Command executed successfully with no output]"
+	}
+	return result
 }

adk/middlewares/filesystem/filesystem_test.go

@@ -475,6 +475,15 @@ func TestExecuteTool(t *testing.T) {
 			input:    `{"command": "failing command"}`,
 			expected: "error output...\n[Command failed with exit code 2]\n[Output was truncated due to size limits]",
 		},
+		{
+			name: "successful command with no output",
+			resp: &filesystem.ExecuteResponse{
+				Output:   "",
+				ExitCode: ptrOf(0),
+			},
+			input:    `{"command": "mkdir /tmp/test"}`,
+			expected: "[Command executed successfully with no output]",
+		},
 	}
 
 	for _, tt := range tests {