fetch 0.11.0

HTTP client with resilience, observability, and Tokio runtime support.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140

// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.

//! This example demonstrates how to use the HTTP client with multiple REST endpoints
//! and templated URIs for more complex API interactions with multiple target paths.

use fetch::fake::FakeDeps;
use fetch::{BaseUri, HttpClient};
use ohno::AppError;
use templated_uri::EscapedString;

use crate::crates_io_mock::crates_io_fake_handler;

#[path = "util/crates_io_mock.rs"]
mod crates_io_mock;

mod api {
    use fetch::HttpClient;
    use templated_uri::{EscapedString, templated};

    type Result<T, E = ohno::AppError> = std::result::Result<T, E>;

    pub struct CratesClient {
        client: HttpClient,
    }

    impl CratesClient {
        pub(crate) fn new(client: HttpClient) -> Self {
            Self { client }
        }

        async fn fetch<T>(&self, api_endpoint: CratesApi) -> Result<T>
        where
            T: serde::de::DeserializeOwned,
        {
            let result = self
                .client
                .get(templated_uri::Uri::from(api_endpoint))
                .header("User-Agent", "http-client")
                .fetch_json::<T>()
                .await?
                .into_body();
            Ok(result)
        }

        pub async fn get_crate(&self, crate_name: EscapedString) -> Result<CrateResponse> {
            let api_endpoint = CratesApi::get_crate(crate_name);
            self.fetch(api_endpoint).await
        }

        pub async fn search_crates(&self, query: EscapedString) -> Result<CratesResponse> {
            let search_url = CratesApi::search_crates(query);
            self.fetch(search_url).await
        }
    }

    #[derive(serde::Deserialize, Debug)]
    pub struct CrateResponse {
        #[serde(rename = "crate")]
        pub model: Crate,
    }

    #[derive(serde::Deserialize, Debug)]
    pub struct CratesResponse {
        #[serde(rename = "crates")]
        pub crates: Vec<Crate>,
    }

    #[derive(serde::Deserialize, Debug)]
    pub struct Crate {
        pub name: String,
        pub downloads: u64,
        pub description: String,
    }

    #[templated]
    #[derive(Clone)]
    enum CratesApi {
        Crate(CrateUrl),
        CrateSearch(CrateSearchUrl),
    }

    impl CratesApi {
        fn get_crate(crate_name: EscapedString) -> Self {
            CrateUrl { crate_name }.into()
        }
        fn search_crates(query: EscapedString) -> Self {
            CrateSearchUrl { q: query }.into()
        }
    }

    // See http_client_telemetry.rs example for cases where URIs have classified components.
    #[templated(template = "/api/v1/crates/{crate_name}", unredacted)]
    #[derive(Clone)]
    struct CrateUrl {
        crate_name: EscapedString,
    }

    // See http_client_telemetry.rs example for cases where URIs have classified components.
    #[templated(template = "/api/v1/crates{?q}", unredacted)]
    #[derive(Clone)]
    struct CrateSearchUrl {
        q: EscapedString,
    }
}

#[tokio::main]
async fn main() -> Result<(), AppError> {
    let crate_name = EscapedString::from_static("serde");

    let client =
        HttpClient::new_fake(crates_io_fake_handler(crate_name.to_string())).with_base_uri(BaseUri::from_static("https://crates.io/"));

    let watch = FakeDeps::default().clock.stopwatch();
    let api_client = api::CratesClient::new(client);
    let crate_response = api_client.get_crate(crate_name.clone()).await?;

    println!("Single crate response:");

    println!(
        "crate: {}, downloads: {}, took: {} ms, description: '{}'",
        crate_name,
        crate_response.model.downloads,
        watch.elapsed().as_millis(),
        crate_response.model.description,
    );

    let search_response = api_client.search_crates(crate_name).await?;

    println!("Crate search response:");

    for response in &search_response.crates {
        println!(
            "crate: {}, downloads: {}, description: '{}'",
            response.name, response.downloads, response.description,
        );
    }

    Ok(())
}