[TO CLOSE] Add pagination parameter for GET sentences

src/main.rs

@@ -1,4 +1,4 @@
-#![feature(plugin)]
+#![feature(plugin, custom_derive)]
 #![plugin(rocket_codegen)]
 
 extern crate rocket;

src/sentences.rs

@@ -2,7 +2,10 @@ extern crate uuid;
 extern crate xml;
 
 use rocket::Response;
-use rocket_contrib::Json;
+use rocket_contrib::{
+    Json,
+    UUID,
+};
 use rocket::http::{
     Status,
     ContentType,
@@ -13,6 +16,7 @@ use postgres::error::{
 };
 use self::xml::reader::EventReader;
 use self::xml::reader::XmlEvent::{Characters, Whitespace};
+use self::uuid::Uuid;
 
 use std::io::Cursor;
 
@@ -26,6 +30,11 @@ pub struct Sentence {
     pub structure: Option<String>,
 }
 
+#[derive(FromForm)]
+struct LastId {
+    pub id: UUID,
+}
+
 #[post("/sentences", format="application/json", data="<sentence>")]
 fn create_sentence<'r>(
     connection: db::DbConnection,
@@ -113,12 +122,14 @@ fn create_sentence<'r>(
         .finalize()
 }
 
-
-#[get("/sentences")]
+#[get("/sentences?<last_id>")]
 fn get_all_sentences<'r>(
     connection: db::DbConnection,
+    last_id: LastId,
 ) -> Response<'r> {
 
+    let real_uuid : Uuid = *last_id.id;
+
     let result = connection.query(
         r#"
             SELECT
@@ -128,19 +139,19 @@ fn get_all_sentences<'r>(
                 structure::text
             FROM sentence
             JOIN language ON (sentence.language_id = language.id)
+            WHERE sentence.id > $1
             ORDER BY
                 added_at,
                 sentence.id
-            LIMIT 100
+            LIMIT 10
         "#,
-        &[],
+        &[&real_uuid],
     );
 
     let rows = result.expect("problem while getting sentence");
 
     let mut sentences : Vec<Sentence> = Vec::with_capacity(100);
 
-
     for row in rows.iter() {
         let sentence = Sentence {
             id: row.get(0),

tests/test_get_all_sentences.rs

@@ -3,7 +3,12 @@ extern crate uuid;
 
 #[macro_use] extern crate serde_derive;
 
-use reqwest::StatusCode;
+use reqwest::{
+    StatusCode,
+    Url,
+};
+
+use std::str::FromStr;
 
 mod db;
 
@@ -51,7 +56,12 @@ fn test_get_all_sentences_returns_200() {
         tests_commons::SERVICE_URL,
     );
 
-    let mut response = reqwest::get(&url).unwrap();
+    let url = Url::parse_with_params(
+        &url,
+        &[("id", "00000000-0000-0000-0000-000000000000")],
+    ).unwrap();
+
+    let mut response = reqwest::get(url).unwrap();
 
     assert_eq!(
         response.status(),
@@ -65,3 +75,88 @@ fn test_get_all_sentences_returns_200() {
         2,
     );
 }
+
+#[test]
+fn test_get_paginated_sentences() {
+
+    let connection = db::get_connection();
+    db::clear(&connection);
+
+    let english_iso639_3 = "eng";
+    db::insert_language(
+        &connection,
+        &english_iso639_3,
+    );
+
+    let base_url = format!(
+        "{}/sentences",
+        tests_commons::SERVICE_URL,
+    );
+
+    /* insert multiple sentences with different
+       content and "consecutives" uuids,
+       from a full-zeros uuid to x-x-x-x-...13 */
+
+    let uuid_common = "00000000-0000-0000-0000-0000000000";
+
+    const SENTENCE_MAX_INDEX: usize = 15;
+    for id in 1..SENTENCE_MAX_INDEX {
+
+        /* ensure the uuids strings are all valid uuids */
+
+        const UUIDS_PER_SET: usize = 10;
+        let uuid = if id >= UUIDS_PER_SET {
+            format!("{}{}0", uuid_common, id - UUIDS_PER_SET)
+        } else {
+            format!("{}0{}", uuid_common, id)
+        };
+
+        db::insert_sentence(
+            &connection,
+            &uuid::Uuid::from_str(&uuid).unwrap(),
+            &format!("Sentence {}", id),
+            &english_iso639_3,
+        );
+    }
+
+    let url = Url::parse_with_params(
+        &base_url,
+        &[("id", "00000000-0000-0000-0000-000000000000")],
+    ).unwrap();
+
+    let mut response = reqwest::get(url).unwrap();
+
+    assert_eq!(
+        response.status(),
+        StatusCode::Ok,
+    );
+
+    let sentences = response.json::<tests_commons::Sentences>().unwrap();
+
+    assert_eq!(
+        sentences.len(),
+        10,
+    );
+
+    let last_sentence = sentences.last().unwrap();
+    let last_id = last_sentence.id.unwrap().to_string();
+
+    let url = Url::parse_with_params(
+        &base_url,
+        &[("id", last_id)],
+    ).unwrap();
+
+    let mut response = reqwest::get(url).unwrap();
+
+    assert_eq!(
+        response.status(),
+        StatusCode::Ok,
+    );
+
+    let sentences = response.json::<tests_commons::Sentences>().unwrap();
+
+    assert_eq!(
+        sentences.len(),
+        3,
+    );
+}