frontend: Show feature flags in topbar and separate page

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>