reddit/
client.rs

1use crate::{
2    error::Error,
3    types::Thing,
4};
5
6// Guesses for good defaults for the user agent.
7
8// TODO: Extract from target
9const DEFAULT_PLATFORM: &str = "pc";
10
11const DEFAULT_APP_ID: &str = env!("CARGO_PKG_NAME");
12const DEFAULT_APP_VERSION: &str = env!("CARGO_PKG_VERSION");
13
14// TODO: Is there really a good default to choose here?
15const DEFAULT_REDDIT_USERNAME: &str = "deleted";
16
17/// A client to access reddit
18#[derive(Clone)]
19pub struct Client {
20    /// The inner http client.
21    ///
22    /// It probably shouldn't be used directly by you.
23    /// It also sets a strange user-agent as well in accordance with reddit's request.
24    pub client: reqwest::Client,
25}
26
27impl Client {
28    /// Create a new [`Client`].
29    pub fn new() -> Self {
30        Self::new_with_user_agent(
31            DEFAULT_PLATFORM,
32            DEFAULT_APP_ID,
33            DEFAULT_APP_VERSION,
34            DEFAULT_REDDIT_USERNAME,
35        )
36    }
37
38    /// Create a new [`Client`] with a user-agent.
39    ///
40    /// See https://github.com/reddit-archive/reddit/wiki/API#rules
41    pub fn new_with_user_agent(
42        platform: &str,
43        app_id: &str,
44        app_version: &str,
45        reddit_username: &str,
46    ) -> Self {
47        let user_agent = format!("{platform}:{app_id}:v{app_version} (by /u/{reddit_username})");
48
49        let mut client_builder = reqwest::Client::builder();
50        client_builder = client_builder.user_agent(user_agent);
51
52        let client = client_builder
53            .build()
54            .expect("failed to build reddit client");
55
56        Self { client }
57    }
58
59    /// Get the top posts of a subreddit where subreddit is the name and num_posts is the number of posts to retrieve.
60    pub async fn get_subreddit(&self, subreddit: &str, num_posts: usize) -> Result<Thing, Error> {
61        let url = format!("https://www.reddit.com/r/{subreddit}.json?limit={num_posts}");
62        let res = self.client.get(&url).send().await?.error_for_status()?;
63
64        // Reddit will redirect us here if the subreddit could not be found.
65        const SEARCH_URL: &str = "https://www.reddit.com/subreddits/search.json?";
66        if res.url().as_str().starts_with(SEARCH_URL) {
67            return Err(Error::SubredditNotFound);
68        }
69
70        let text = res.text().await?;
71        serde_json::from_str(&text).map_err(|error| Error::Json {
72            data: text.into(),
73            error,
74        })
75    }
76
77    /// Get the post data for a post from a given subreddit
78    pub async fn get_post(&self, subreddit: &str, post_id: &str) -> Result<Vec<Thing>, Error> {
79        let url = format!("https://www.reddit.com/r/{subreddit}/comments/{post_id}.json");
80        Ok(self
81            .client
82            .get(&url)
83            .send()
84            .await?
85            .error_for_status()?
86            .json()
87            .await?)
88    }
89}
90
91impl Default for Client {
92    fn default() -> Self {
93        Self::new()
94    }
95}
96
97#[cfg(test)]
98mod test {
99    use super::*;
100    use crate::Listing;
101
102    async fn get_subreddit(name: &str) -> Result<(), Error> {
103        let client = Client::new();
104        // 25 is the default
105        let subreddit = client.get_subreddit(name, 100).await?;
106        println!(
107            "# of children: {}",
108            subreddit.data.as_listing().unwrap().children.len()
109        );
110        Ok(())
111    }
112
113    #[tokio::test]
114    #[ignore]
115    async fn get_post_works() {
116        let post_data = [
117            ("dankmemes", "h966lq"),
118            // ("dankvideos", "h8p0py"), // Subreddit got privated, last tested 12/23/2022. Uncomment in the future to see if that is still the case.
119            ("oddlysatisfying", "ha7obv"),
120        ];
121        let client = Client::new();
122
123        for (subreddit, post_id) in post_data.iter() {
124            let post = client
125                .get_post(subreddit, post_id)
126                .await
127                .expect("failed to get post");
128            dbg!(&post);
129        }
130    }
131
132    #[tokio::test]
133    #[ignore]
134    async fn get_subreddit_works() {
135        let subreddits = [
136            "forbiddensnacks",
137            "dankmemes",
138            "cursedimages",
139            "MEOW_IRL",
140            "cuddleroll",
141            "cromch",
142            "cats",
143            "cursed_images",
144            "aww",
145            "dogpictures",
146        ];
147
148        for subreddit in subreddits.iter() {
149            match get_subreddit(subreddit).await {
150                Ok(()) => {}
151                Err(Error::Json { data, .. }) => {
152                    /// See: https://github.com/dtolnay/path-to-error/issues/1
153                    #[derive(Debug, serde::Deserialize)]
154                    struct Subreddit {
155                        #[expect(dead_code)]
156                        data: Listing,
157                    }
158
159                    let jd = &mut serde_json::Deserializer::from_str(&data);
160                    let error = serde_path_to_error::deserialize::<_, Subreddit>(jd)
161                        .expect_err("deserializing with serde_path_to_error should error too");
162
163                    tokio::fs::write("subreddit-error.json", data.as_bytes())
164                        .await
165                        .expect("failed to save error");
166
167                    panic!("failed to get subreddit \"{subreddit}\": {error:#?}");
168                }
169                Err(error) => {
170                    panic!("failed to get subreddit \"{subreddit}\": {error:#?}");
171                }
172            }
173        }
174    }
175
176    #[tokio::test]
177    #[ignore]
178    async fn invalid_subreddit() {
179        let client = Client::new();
180        let error = client.get_subreddit("gfdghfj", 25).await.unwrap_err();
181        assert!(error.is_subreddit_not_found(), "error = {error:#?}");
182    }
183}
reddit/client.rs

reddit/
client.rs
