使用Retrofit Gson Converter时Kotlin空安全失效问题排查

服务器在短信验证码无效时返回200状态码（本应返回4xx错误码），但我的Android代码未捕获到空值问题，最终UI/ViewModel层拿到Result.Success(null)并崩溃——所有字段均定义为非空String，未使用String?。近期刚将Kotlin从1.8.*升级至1.9.0，这是否是问题根源？

数据源层代码 #

override suspend fun forgotPasswordCheckCode(phone: String, code: String): String {
    return try {
        authApi.forgotPasswordCheckCode(
            NetworkForgotPasswordCheckCodeRequest(
                phone = phone,
                code = code
            )
        ).data.verificationToken
    } catch (e: Throwable) {
        throw ... // 解析HTTP错误的逻辑，但此处未捕获到异常
    }
}

仓库层代码 #

override fun forgotPasswordCheckCode(phone: String, code: String): Flow<String> = flow {
    val token = authDataSource.forgotPasswordCheckCode(phone, code)
    emit(token)
}

领域层用例的包装逻辑 #

inline fun <reified T> Flow<T>.wrapAsResult(): Flow<Result<T>> {
    return this
        .map<T, Result<T>> {
            Result.Success(it)
        }
        .onStart { emit(Result.Loading) }
        .catch { error ->
            Timber.e(error, "Flow")
            emit(Result.Error(error))
        }
}

序列化实体类 #

data class NetworkForgotPasswordCheck(
    @SerializedName("verificationToken")
    val verificationToken: String,
)

data class NetworkDataResponse<T>(@SerializedName("data") val data: T)

Retrofit接口定义 #

@POST("Auth/verify/sms/password/complete")
suspend fun forgotPasswordCheckCode(
    @Body checkCodeRequest: NetworkForgotPasswordCheckCodeRequest
): NetworkDataResponse<NetworkForgotPasswordCheck>

服务器返回示例 #

<-- 200 https://.../Auth/verify/sms/password/complete (84ms)
{"data":{"message":"Unable to verify subject with given code"}}

依赖版本 #

[versions]
kotlin = "1.9.0"
okhttpBom = "4.10.0"
retrofit = "2.9.0"

内容的提问来源于stack exchange，提问作者user924