Handle @files in example output

pkg/server/build.go

@@ -152,6 +152,20 @@ func (s *Server) testModel(mod *model.Model, dir string, logWriter logger.Logger
 		if err := validateServingExampleInput(help, example.Input); err != nil {
 			return nil, fmt.Errorf("Example input doesn't match run arguments: %w", err)
 		}
+		var expectedOutput []byte = nil
+		outputIsFile := false
+		if example.Output != "" {
+			if strings.HasPrefix(example.Output, "@") {
+				outputIsFile = true
+				expectedOutput, err = os.ReadFile(filepath.Join(dir, example.Output[1:]))
+				if err != nil {
+					return nil, fmt.Errorf("Failed to read example output file %s: %w", example.Output[1:], err)
+				}
+			} else {
+				expectedOutput = []byte(example.Output)
+			}
+		}
+
 		input := serving.NewExampleWithBaseDir(example.Input, dir)
 
 		result, err := deployment.RunInference(input, logWriter)
@@ -164,8 +178,14 @@ func (s *Server) testModel(mod *model.Model, dir string, logWriter logger.Logger
 			return nil, fmt.Errorf("Failed to read output: %w", err)
 		}
 		logWriter.Infof(fmt.Sprintf("Inference result length: %d, mime type: %s", len(outputBytes), output.MimeType))
-		if example.Output != "" && strings.TrimSpace(string(outputBytes)) != example.Output {
-			return nil, fmt.Errorf("Output %s doesn't match expected: %s", outputBytes, example.Output)
+		if expectedOutput != nil {
+			if !bytes.Equal(expectedOutput, outputBytes) {
+				if outputIsFile {
+					return nil, fmt.Errorf("Output file contents doesn't match expected %s", example.Output[1:])
+				} else {
+					return nil, fmt.Errorf("Output %s doesn't match expected: %s", string(outputBytes), example.Output)
+				}
+			}
 		}
 	}