frontend: Order default features in tree structure

Order features that are enabled by default in flat
tree structure. At the same time report correct
number of features being enabled by default.

Author: almusil

src/db/types.rs

@@ -4,8 +4,8 @@ use serde::Serialize;
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, FromSql, ToSql)]
 #[postgres(name = "feature")]
 pub struct Feature {
-    name: String,
-    subfeatures: Vec<String>,
+    pub(crate) name: String,
+    pub(crate) subfeatures: Vec<String>,
 }
 
 impl Feature {

src/web/crate_details.rs

@@ -103,7 +103,6 @@ impl CrateDetails {
                 releases.license,
                 releases.documentation_url,
                 releases.default_target,
-                releases.features,
                 doc_coverage.total_items,
                 doc_coverage.documented_items,
                 doc_coverage.total_items_needing_examples,
@@ -149,7 +148,6 @@ impl CrateDetails {
             default_target: krate.get("default_target"),
             doc_targets: MetaData::parse_doc_targets(krate.get("doc_targets")),
             yanked: krate.get("yanked"),
-            features: MetaData::parse_features(krate.get("features")),
         };
 
         let documented_items: Option<i32> = krate.get("documented_items");
@@ -817,14 +815,45 @@ mod tests {
         });
     }
 
+    #[test]
+    fn feature_flags_with_nested_default() {
+        wrapper(|env| {
+            let features = [
+                ("default".into(), vec!["feature1".into()]),
+                ("feature1".into(), vec!["feature2".into()]),
+                ("feature2".into(), Vec::new()),
+            ]
+            .iter()
+            .cloned()
+            .collect::<HashMap<String, Vec<String>>>();
+            env.fake_release()
+                .name("library")
+                .version("0.1.0")
+                .features(features)
+                .create()?;
+
+            let page = kuchiki::parse_html().one(
+                env.frontend()
+                    .get("/crate/library/0.1.0/features")
+                    .send()?
+                    .text()?,
+            );
+            assert!(page.select_first(r#"p[data-id="empty-features"]"#).is_err());
+            let def_len = page
+                .select_first(r#"b[data-id="default-feature-len"]"#)
+                .unwrap();
+            assert_eq!(def_len.text_contents(), "3");
+            Ok(())
+        });
+    }
+
     #[test]
     fn feature_flags_report_null() {
         wrapper(|env| {
             let id = env
                 .fake_release()
                 .name("library")
                 .version("0.1.0")
-                .features(HashMap::new())
                 .create()?;
 
             env.db()

src/web/features.rs

@@ -1,3 +1,4 @@
+use crate::db::types::Feature;
 use crate::{
     db::Pool,
     impl_webpage,
@@ -6,10 +7,13 @@ use crate::{
 use iron::{IronResult, Request, Response};
 use router::Router;
 use serde::Serialize;
+use std::collections::{HashMap, VecDeque};
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize)]
 struct FeaturesPage {
     metadata: MetaData,
+    features: Option<Vec<Feature>>,
+    default_len: usize,
 }
 
 impl_webpage! {
@@ -22,9 +26,63 @@ pub fn build_features_handler(req: &mut Request) -> IronResult<Response> {
     let version = cexpect!(req, router.find("version"));
 
     let mut conn = extension!(req, Pool).get()?;
+    let rows = ctry!(
+        req,
+        conn.query(
+            "SELECT releases.features FROM releases
+            INNER JOIN crates ON crates.id = releases.crate_id
+            WHERE crates.name = $1 AND releases.version = $2",
+            &[&name, &version]
+        )
+    );
+
+    let row = cexpect!(req, rows.get(0));
+
+    let mut default_len = 0;
+    let features = row
+        .get::<'_, usize, Option<Vec<Feature>>>(0)
+        .map(|raw| {
+            raw.into_iter()
+                .filter(|feature| !feature.is_private())
+                .map(|feature| (feature.name.clone(), feature))
+                .collect::<HashMap<String, Feature>>()
+        })
+        .map(|mut feature_map| {
+            let mut features = get_tree_structure_from_default(&mut feature_map);
+            let mut remaining = feature_map
+                .into_iter()
+                .map(|(_, feature)| feature)
+                .collect::<Vec<Feature>>();
+            remaining.sort_by_key(|feature| feature.subfeatures.len());
+
+            default_len = features.len();
+
+            features.extend(remaining.into_iter().rev());
+            features
+        });
 
     FeaturesPage {
         metadata: cexpect!(req, MetaData::from_crate(&mut conn, &name, &version)),
+        features,
+        default_len,
     }
     .into_response(req)
 }
+
+fn get_tree_structure_from_default(feature_map: &mut HashMap<String, Feature>) -> Vec<Feature> {
+    let mut features = Vec::new();
+    let mut queue: VecDeque<String> = VecDeque::new();
+
+    queue.push_back("default".into());
+    while !queue.is_empty() {
+        let name = queue.pop_front().unwrap();
+        if let Some(feature) = feature_map.remove(&name) {
+            feature
+                .subfeatures
+                .iter()
+                .for_each(|sub| queue.push_back(sub.clone()));
+            features.push(feature);
+        }
+    }
+    features
+}

src/web/mod.rs

@@ -91,7 +91,6 @@ mod sitemap;
 mod source;
 mod statics;
 
-use crate::db::types::Feature;
 use crate::{impl_webpage, Context};
 use chrono::{DateTime, Utc};
 use error::Nope;
@@ -522,7 +521,6 @@ pub(crate) struct MetaData {
     pub(crate) default_target: String,
     pub(crate) doc_targets: Vec<String>,
     pub(crate) yanked: bool,
-    pub(crate) features: Option<Vec<Feature>>,
 }
 
 impl MetaData {
@@ -536,8 +534,7 @@ impl MetaData {
                        releases.rustdoc_status,
                        releases.default_target,
                        releases.doc_targets,
-                       releases.yanked,
-                       releases.features
+                       releases.yanked
                 FROM releases
                 INNER JOIN crates ON crates.id = releases.crate_id
                 WHERE crates.name = $1 AND releases.version = $2",
@@ -556,7 +553,6 @@ impl MetaData {
             default_target: row.get(5),
             doc_targets: MetaData::parse_doc_targets(row.get(6)),
             yanked: row.get(7),
-            features: MetaData::parse_features(row.get(8)),
         })
     }
 
@@ -571,14 +567,6 @@ impl MetaData {
             })
             .unwrap_or_else(Vec::new)
     }
-
-    pub(crate) fn parse_features(features: Option<Vec<Feature>>) -> Option<Vec<Feature>> {
-        features.map(|vec| {
-            vec.into_iter()
-                .filter(|feature| !feature.is_private())
-                .collect()
-        })
-    }
 }
 
 #[derive(Debug, Clone, PartialEq, Serialize)]
@@ -857,7 +845,6 @@ mod test {
                 "arm64-unknown-linux-gnu".to_string(),
             ],
             yanked: false,
-            features: None,
         };
 
         let correct_json = json!({
@@ -872,7 +859,6 @@ mod test {
                 "arm64-unknown-linux-gnu",
             ],
             "yanked": false,
-            "features": null
         });
 
         assert_eq!(correct_json, serde_json::to_value(&metadata).unwrap());
@@ -890,7 +876,6 @@ mod test {
                 "arm64-unknown-linux-gnu",
             ],
             "yanked": false,
-            "features": null,
         });
 
         assert_eq!(correct_json, serde_json::to_value(&metadata).unwrap());
@@ -908,7 +893,6 @@ mod test {
                 "arm64-unknown-linux-gnu",
             ],
             "yanked": false,
-            "features": null,
         });
 
         assert_eq!(correct_json, serde_json::to_value(&metadata).unwrap());

src/web/source.rs

@@ -58,8 +58,7 @@ impl FileList {
                         releases.files,
                         releases.default_target,
                         releases.doc_targets,
-                        releases.yanked,
-                        releases.features
+                        releases.yanked
                 FROM releases
                 LEFT OUTER JOIN crates ON crates.id = releases.crate_id
                 WHERE crates.name = $1 AND releases.version = $2",
@@ -138,7 +137,6 @@ impl FileList {
                     default_target: rows[0].get(6),
                     doc_targets: MetaData::parse_doc_targets(rows[0].get(7)),
                     yanked: rows[0].get(8),
-                    features: MetaData::parse_features(rows[0].get(9)),
                 },
                 files: file_list,
             })

templates/crate/features.html

@@ -26,15 +26,15 @@
                 <div class="pure-menu package-menu">
                     <ul class="pure-menu-list">
                         <li class="pure-menu-heading">Feature flags</li>
-                        {%- if metadata.features -%}
-                            {%- for feature in metadata.features -%}
+                        {%- if features -%}
+                            {%- for feature in features -%}
                                 <li class="pure-menu-item">
                                     <a href="#{{ feature.name }}" class="pure-menu-link" style="text-align:center;">
                                         {{ feature.name }}
                                     </a>
                                 </li>
                             {%- endfor -%}
-                        {%- elif metadata.features is iterable -%}
+                        {%- elif features is iterable -%}
                             <li class="pure-menu-item">
                                 <span style="font-size: 13px;">This release does not have any feature flags.</span>
                             </li>
@@ -49,15 +49,9 @@
 
             <div class="pure-u-1 pure-u-sm-17-24 pure-u-md-19-24 package-details" id="main">
                 <h1>{{ metadata.name }}</h1>
-                {%- if metadata.features -%}
-                    <p>This version has <b>{{ metadata.features | length }}</b> feature flags, <b data-id="default-feature-len">
-                        {%- if metadata.features[0].name == 'default' -%}
-                            {{ metadata.features[0].subfeatures | length }}
-                        {%- else -%}
-                            0
-                        {%- endif -%}
-                    </b> of them enabled by <b>default</b>.</p>
-                    {%- for feature in metadata.features -%}
+                {%- if features -%}
+                    <p>This version has <b>{{ features | length }}</b> feature flags, <b data-id="default-feature-len">{{ default_len }}</b> of them enabled by <b>default</b>.</p>
+                    {%- for feature in features -%}
                         <h3 id="{{ feature.name }}">{{ feature.name }}</h3>
                         <ul class="pure-menu-list">
                             {%- if feature.subfeatures -%}
@@ -71,7 +65,7 @@ <h3 id="{{ feature.name }}">{{ feature.name }}</h3>
                             {%- endif -%}
                         </ul>
                     {%- endfor -%}
-                {%- elif metadata.features is iterable  -%}
+                {%- elif features is iterable  -%}
                     <p data-id="empty-features">This release does not have any feature flags.</p>
                 {%- else -%}
                     <p data-id="null-features">Feature flags data are not available for this release.</p>