94 lines
2.3 KiB
Rust
94 lines
2.3 KiB
Rust
use actix_web::HttpResponse;
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use serde::{Deserialize, Serialize};
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fn get_pagination_header(
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instance_url: &str,
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path: &str,
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last_id: &str,
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) -> String {
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let next_page_url = format!(
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"{}{}?max_id={}",
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instance_url,
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path,
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last_id
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);
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// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Link
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format!(r#"<{}>; rel="next""#, next_page_url)
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}
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pub fn get_paginated_response(
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instance_url: &str,
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path: &str,
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items: Vec<impl Serialize>,
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maybe_last_item_id: Option<impl ToString>,
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) -> HttpResponse {
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if let Some(last_item_id) = maybe_last_item_id {
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let pagination_header = get_pagination_header(
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instance_url,
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path,
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&last_item_id.to_string(),
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);
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HttpResponse::Ok()
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.append_header(("Link", pagination_header))
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.json(items)
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} else {
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HttpResponse::Ok().json(items)
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}
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}
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const PAGE_MAX_SIZE: u16 = 200;
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#[derive(Debug, Deserialize)]
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#[serde(try_from="u16")]
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pub struct PageSize(u16);
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impl PageSize {
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pub fn new(size: u16) -> Self { Self(size) }
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pub fn inner(&self) -> u16 { self.0 }
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}
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impl TryFrom<u16> for PageSize {
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type Error = &'static str;
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fn try_from(value: u16) -> Result<Self, Self::Error> {
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if value > 0 && value <= PAGE_MAX_SIZE {
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Ok(Self(value))
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} else {
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Err("expected an integer between 0 and 201")
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}
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}
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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const INSTANCE_URL: &str = "https://example.org";
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#[test]
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fn test_get_next_page_link() {
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let result = get_pagination_header(
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INSTANCE_URL,
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"/api/v1/notifications",
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"123",
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);
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assert_eq!(
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result,
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r#"<https://example.org/api/v1/notifications?max_id=123>; rel="next""#,
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);
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}
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#[test]
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fn test_deserialize_page_size() {
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let value: PageSize = serde_json::from_str("10").unwrap();
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assert_eq!(value.inner(), 10);
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let expected_error = "expected an integer between 0 and 201";
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let error = serde_json::from_str::<PageSize>("0").unwrap_err();
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assert_eq!(error.to_string(), expected_error);
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let error = serde_json::from_str::<PageSize>("201").unwrap_err();
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assert_eq!(error.to_string(), expected_error);
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}
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}
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