Rust爬取必应第三方网站的总页数(1)

[dependencies]
# json 序列化 反序列化
serde_json = "1.0"
# 时间工具包
chrono = {version = "0.4.31", features = ["serde"] }
# http 客户端 爬取相关数据使用
reqwest = {version = "0.11.22", features = ["json", "stream"] }
# reqwest 增强
futures-util = "0.3.29"
futures-core = "0.3.29"
# rust知名异步框架 实现多线程等
tokio = { version = "1.34.0", features = ["rt", "rt-multi-thread", "macros"] }
# 宏 可以静态分配中调用方法
lazy_static = "1.4.0"
# 对爬取的html进行解析处理
htmler = "0.1.1"
# 轻松实现错误处理
anyhow = "1.0.75"
# 异步方法测试宏
actix-rt = "2.9.0"

use lazy_static::lazy_static;
use reqwest::Client;
use htmler::Selector;

#[tokio::main]
async fn main() {

}

lazy_static!{
    /// bing 必应图片第三方网站
    static ref BING_URL: String =  "https://peapix.com/bing/cn".to_string();
    static ref BING_PAGE_NUMBERS_SELECTOR: Selector = Selector::parse(r#"a[class="page-link"]"#).unwrap();
}


/// `get_bing_total_page` 获取bing网页中总页数
///
/// # Examples
///
/// ```
/// let total = get_bing_total_page();
///
/// assert_eq!(Some(50), total);
/// ```
async fn get_bing_total_page() -> Option<i32>{
    let client = Client::new();
    if let Ok(res) = client.get(BING_URL.clone()).send().await{
        let html_dom = res.text().await.unwrap();
        let html = htmler::Html::parse_fragment(&html_dom);
        if let Some(node) = html.select(&BING_PAGE_NUMBERS_SELECTOR).last(){
            return Some(node.inner_html().parse::<i32>().unwrap());
        }
    }
    None
}

#[cfg(test)]
mod tests{
    use crate::get_bing_total_page;

    #[actix_rt::test]
    async fn get_bing_total_page_test(){
        let total = get_bing_total_page().await;
        assert_eq!(Some(50), total)
    }
}