Alamofire中Adapter执行完成后请求未发起问题求助

问题场景 #

服务器采用JWT进行用户认证，无令牌时通过Alamofire的Adapter先获取新令牌，再发起原请求。已确认调用completion(.success(modifiedRequest))，但原请求未发出（经Proxyman验证）。

问题代码 #

lazy private(set) var tokenAdapter = Adapter { [weak self] request, session, completion in
    
    var modifiedRequest = request
    
    // Step1
    if let accessToken = self?.credential.accessToken {
        
        let bearerToken = "Bearer \(accessToken)"
        
        modifiedRequest
            .addValue("Authorization", forHTTPHeaderField: bearerToken)
        
        completion(.success(modifiedRequest))
        
    } else {
        
        // 从未获取过令牌的情况
        guard let deviceId = self?.credential.devideIdentifier,
              let requestBox = self?.issueToken(deviceIdentity: DeviceIdentityDTO(imei: deviceId))
        else {
            return completion(.failure(RequestGenerationError.crendentialIsNotAvailable))
        }
    
        do {
            let issueTokenRequest = try requestBox.endPoint.toRequest()
                
            // Step2
            session
                .request(issueTokenRequest)
                .responseDecodable(of: TokenResponse.self) { response in
                    
                    if let error = response.error {
                        
                        return completion(.failure(error))
                    }
                    
                    if let responseData = try? response.result.get().data {
                        
                        let accessToken = responseData.accessToken
                        let refreshToken = responseData.refreshToken
                        
                        self?.credential.renewalTokens(
                            accessToken: accessToken,
                            refreshToken: refreshToken
                        )
                        
                        let bearerToken = "Bearer \(accessToken)"
                        
                        modifiedRequest
                            .addValue("Authorization", forHTTPHeaderField: bearerToken)
                        
                        
                        // Step3
                        return completion(.success(modifiedRequest))
                    }
                    
                    return completion(.failure(ResponseError.dataIsNotFound))
                }
            
        } catch {
            completion(.failure(error))
        }
    }
}

排查与修复方案 #

核心问题：HTTP头字段添加参数顺序错误 #

Alamofire的URLRequest扩展方法addValue(_ value: String, forHTTPHeaderField field: String)参数顺序为值在前，字段名在后，但代码中完全写反了：

• 错误写法：modifiedRequest.addValue("Authorization", forHTTPHeaderField: bearerToken)
• 正确写法：modifiedRequest.addValue(bearerToken, forHTTPHeaderField: "Authorization")

错误的参数顺序会导致添加一个名为Bearer xxxxxx的无效HTTP头，而非正确的Authorization: Bearer xxxxxx，这会触发Alamofire内部处理异常，直接导致原请求无法发起。

其他潜在问题修复 #

1. 拼写错误修正：devideIdentifier应为deviceIdentifier，若此字段为空会直接进入failure分支，阻断原请求。
2. 线程安全处理：建议在主线程调用completion，避免异步回调线程问题：

DispatchQueue.main.async {
    completion(.success(modifiedRequest))
}

3. 错误处理优化：try? response.result.get()会吞掉错误，改为明确的错误捕获：

do {
    let tokenResponse = try response.result.get()
    guard let responseData = tokenResponse.data else {
        return completion(.failure(ResponseError.dataIsNotFound))
    }
    // 后续令牌处理逻辑
} catch {
    return completion(.failure(error))
}

内容的提问来源于stack exchange，提问作者Choijun0