Allow multiple keywords in crate search

This commit allows multiple `keyword=` parameters in the querystring to
enable searching for all crates under the specified keywords

Towards #1461

Author: Paul Woolcock

Cargo.lock

@@ -62,6 +62,7 @@ tempdir = "0.3.7"
 parking_lot = "0.7.1"
 jemallocator = { version = "0.1.8", features = ['unprefixed_malloc_on_supported_platforms', 'profiling'] }
 jemalloc-ctl = "0.2.0"
+collecting-hashmap = "0.1"
 
 lettre = { version = "0.9", git = "https://github.com/lettre/lettre" }
 lettre_email = { version = "0.9", git = "https://github.com/lettre/lettre" }

Cargo.toml

@@ -12,6 +12,7 @@ mod prelude {
     pub use crate::middleware::current_user::RequestUser;
 
     use std::collections::HashMap;
+    use collecting_hashmap::CollectingHashMap;
     use std::io;
 
     use serde::Serialize;
@@ -21,7 +22,7 @@ mod prelude {
         fn redirect(&self, url: String) -> Response;
 
         fn json<T: Serialize>(&self, t: &T) -> Response;
-        fn query(&self) -> HashMap<String, String>;
+        fn query(&self) -> CollectingHashMap<String, String>;
         fn wants_json(&self) -> bool;
         fn pagination(&self, default: usize, max: usize) -> CargoResult<(i64, i64)>;
     }
@@ -31,7 +32,7 @@ mod prelude {
             crate::util::json_response(t)
         }
 
-        fn query(&self) -> HashMap<String, String> {
+        fn query(&self) -> CollectingHashMap<String, String> {
             url::form_urlencoded::parse(self.query_string().unwrap_or("").as_bytes())
                 .map(|(a, b)| (a.into_owned(), b.into_owned()))
                 .collect()

src/controllers.rs

@@ -99,14 +99,17 @@ pub fn search(req: &mut dyn Request) -> CargoResult<Response> {
         );
     }
 
-    if let Some(kw) = params.get("keyword") {
+    if let Some(kws) = params.get_all("keyword") {
         has_filter = true;
+
+        use diesel::dsl::any;
+        let names: Vec<_> = kws.iter().map(|name| name.to_lowercase()).collect();
         query = query.filter(
             crates::id.eq_any(
                 crates_keywords::table
                     .select(crates_keywords::crate_id)
                     .inner_join(keywords::table)
-                    .filter(crate::lower(keywords::keyword).eq(crate::lower(kw))),
+                    .filter(crate::lower(keywords::keyword).eq(any(names))),
             ),
         );
     } else if let Some(letter) = params.get("letter") {

src/controllers/krate/search.rs

@@ -139,6 +139,7 @@ fn index_queries() {
     assert_eq!(anon.search("keyword=kw1").crates.len(), 2);
     assert_eq!(anon.search("keyword=KW1").crates.len(), 2);
     assert_eq!(anon.search("keyword=kw2").crates.len(), 0);
+    assert_eq!(anon.search("keyword=kw1&keyword=kw3").crates.len(), 3);
 
     assert_eq!(anon.search("q=foo&keyword=kw1").crates.len(), 1);
     assert_eq!(anon.search("q=foo2&keyword=kw1").crates.len(), 0);