update

ts/mail/delivery/smtpclient/error-handler.ts

@@ -0,0 +1,141 @@
+/**
+ * SMTP Client Error Handler
+ * Error classification and recovery strategies
+ */
+
+import { SmtpErrorType } from './constants.js';
+import type { ISmtpResponse, ISmtpErrorContext, ISmtpClientOptions } from './interfaces.js';
+import { logDebug } from './utils/logging.js';
+
+export class SmtpErrorHandler {
+  private options: ISmtpClientOptions;
+  
+  constructor(options: ISmtpClientOptions) {
+    this.options = options;
+  }
+  
+  /**
+   * Classify error type based on response or error
+   */
+  public classifyError(error: Error | ISmtpResponse, context?: ISmtpErrorContext): SmtpErrorType {
+    logDebug('Classifying error', this.options, { errorMessage: error instanceof Error ? error.message : String(error), context });
+    
+    // Handle Error objects
+    if (error instanceof Error) {
+      return this.classifyErrorByMessage(error);
+    }
+    
+    // Handle SMTP response codes
+    if (typeof error === 'object' && 'code' in error) {
+      return this.classifyErrorByCode(error.code);
+    }
+    
+    return SmtpErrorType.UNKNOWN_ERROR;
+  }
+  
+  /**
+   * Determine if error is retryable
+   */
+  public isRetryable(errorType: SmtpErrorType, response?: ISmtpResponse): boolean {
+    switch (errorType) {
+      case SmtpErrorType.CONNECTION_ERROR:
+      case SmtpErrorType.TIMEOUT_ERROR:
+        return true;
+      
+      case SmtpErrorType.PROTOCOL_ERROR:
+        // Only retry on temporary failures (4xx codes)
+        return response ? response.code >= 400 && response.code < 500 : false;
+      
+      case SmtpErrorType.AUTHENTICATION_ERROR:
+      case SmtpErrorType.TLS_ERROR:
+      case SmtpErrorType.SYNTAX_ERROR:
+      case SmtpErrorType.MAILBOX_ERROR:
+      case SmtpErrorType.QUOTA_ERROR:
+        return false;
+      
+      default:
+        return false;
+    }
+  }
+  
+  /**
+   * Get retry delay for error type
+   */
+  public getRetryDelay(attempt: number, errorType: SmtpErrorType): number {
+    const baseDelay = 1000; // 1 second
+    const maxDelay = 30000;  // 30 seconds
+    
+    // Exponential backoff with jitter
+    const delay = Math.min(baseDelay * Math.pow(2, attempt - 1), maxDelay);
+    const jitter = Math.random() * 0.1 * delay; // 10% jitter
+    
+    return Math.floor(delay + jitter);
+  }
+  
+  /**
+   * Create enhanced error with context
+   */
+  public createError(
+    message: string,
+    errorType: SmtpErrorType,
+    context?: ISmtpErrorContext,
+    originalError?: Error
+  ): Error {
+    const error = new Error(message);
+    (error as any).type = errorType;
+    (error as any).context = context;
+    (error as any).originalError = originalError;
+    
+    return error;
+  }
+  
+  private classifyErrorByMessage(error: Error): SmtpErrorType {
+    const message = error.message.toLowerCase();
+    
+    if (message.includes('timeout') || message.includes('etimedout')) {
+      return SmtpErrorType.TIMEOUT_ERROR;
+    }
+    
+    if (message.includes('connect') || message.includes('econnrefused') || 
+        message.includes('enotfound') || message.includes('enetunreach')) {
+      return SmtpErrorType.CONNECTION_ERROR;
+    }
+    
+    if (message.includes('tls') || message.includes('ssl') || 
+        message.includes('certificate') || message.includes('handshake')) {
+      return SmtpErrorType.TLS_ERROR;
+    }
+    
+    if (message.includes('auth')) {
+      return SmtpErrorType.AUTHENTICATION_ERROR;
+    }
+    
+    return SmtpErrorType.UNKNOWN_ERROR;
+  }
+  
+  private classifyErrorByCode(code: number): SmtpErrorType {
+    if (code >= 500) {
+      // Permanent failures
+      if (code === 550 || code === 551 || code === 553) {
+        return SmtpErrorType.MAILBOX_ERROR;
+      }
+      if (code === 552) {
+        return SmtpErrorType.QUOTA_ERROR;
+      }
+      if (code === 500 || code === 501 || code === 502 || code === 504) {
+        return SmtpErrorType.SYNTAX_ERROR;
+      }
+      return SmtpErrorType.PROTOCOL_ERROR;
+    }
+    
+    if (code >= 400) {
+      // Temporary failures
+      if (code === 450 || code === 451 || code === 452) {
+        return SmtpErrorType.QUOTA_ERROR;
+      }
+      return SmtpErrorType.PROTOCOL_ERROR;
+    }
+    
+    return SmtpErrorType.UNKNOWN_ERROR;
+  }
+}