Add menu item called Feature flags

Feature flags should show all available features
for current crate version with default being first
is specified.

Author: almusil

src/db/add_package.rs

@@ -42,6 +42,7 @@ pub(crate) fn add_package_into_database(
     let dependencies = convert_dependencies(metadata_pkg);
     let rustdoc = get_rustdoc(metadata_pkg, source_dir).unwrap_or(None);
     let readme = get_readme(metadata_pkg, source_dir).unwrap_or(None);
+    let features = get_features(metadata_pkg);
     let is_library = metadata_pkg.is_library();
 
     let rows = conn.query(
@@ -52,12 +53,12 @@ pub(crate) fn add_package_into_database(
             homepage_url, description, description_long, readme,
             authors, keywords, have_examples, downloads, files,
             doc_targets, is_library, doc_rustc_version,
-            documentation_url, default_target
+            documentation_url, default_target, features
          )
          VALUES (
             $1,  $2,  $3,  $4,  $5,  $6,  $7,  $8,  $9,
             $10, $11, $12, $13, $14, $15, $16, $17, $18,
-            $19, $20, $21, $22, $23, $24, $25
+            $19, $20, $21, $22, $23, $24, $25, $26
          )
          ON CONFLICT (crate_id, version) DO UPDATE
             SET release_time = $3,
@@ -82,7 +83,8 @@ pub(crate) fn add_package_into_database(
                 is_library = $22,
                 doc_rustc_version = $23,
                 documentation_url = $24,
-                default_target = $25
+                default_target = $25,
+                features = $26
          RETURNING id",
         &[
             &crate_id,
@@ -110,6 +112,7 @@ pub(crate) fn add_package_into_database(
             &res.rustc_version,
             &metadata_pkg.documentation,
             &default_target,
+            &serde_json::to_value(features)?,
         ],
     )?;
 
@@ -213,6 +216,21 @@ fn convert_dependencies(pkg: &MetadataPackage) -> Vec<(String, String, String)>
         .collect()
 }
 
+/// Reads features and converts them to Vec<String> with default being first
+fn get_features(pkg: &MetadataPackage) -> Vec<String> {
+    let mut features = Vec::with_capacity(pkg.features.len());
+    if let Some(default) = pkg.features.get("default") {
+        features.push(format!("default = {:?}", default));
+    };
+    features.extend(
+        pkg.features
+            .iter()
+            .filter(|(name, _)| !name.eq(&"default"))
+            .map(|(name, features)| format!("{} = {:?}", name, features)),
+    );
+    features
+}
+
 /// Reads readme if there is any read defined in Cargo.toml of a Package
 fn get_readme(pkg: &MetadataPackage, source_dir: &Path) -> Result<Option<String>> {
     let readme_path = source_dir.join(pkg.readme.as_deref().unwrap_or("README.md"));

src/db/migrate.rs

@@ -457,7 +457,22 @@ pub fn migrate(version: Option<Version>, conn: &mut Client) -> CratesfyiResult<(
                 DROP COLUMN total_items_needing_examples,
                 DROP COLUMN items_with_examples;
             "
-        )
+        ),
+        migration!(
+            context,
+            // version
+            19,
+            // description
+            "Add features that are available for given release",
+            // upgrade query
+            "
+                ALTER TABLE releases ADD COLUMN features JSON;
+            ",
+            // downgrade query
+            "
+                ALTER TABLE releases DROP COLUMN  features;
+            "
+        ),
     ];
 
     for migration in migrations {

src/test/fakes.rs

@@ -5,6 +5,7 @@ use crate::storage::Storage;
 use crate::utils::{Dependency, MetadataPackage, Target};
 use chrono::{DateTime, Utc};
 use failure::Error;
+use std::collections::HashMap;
 use std::sync::Arc;
 
 #[must_use = "FakeRelease does nothing until you call .create()"]
@@ -53,6 +54,15 @@ impl<'a> FakeRelease<'a> {
                 readme: None,
                 keywords: vec!["fake".into(), "package".into()],
                 authors: vec!["Fake Person <[email protected]>".into()],
+                features: [
+                    ("default".into(), vec!["feature1".into(), "feature3".into()]),
+                    ("feature1".into(), Vec::new()),
+                    ("feature2".into(), vec!["feature1".into()]),
+                    ("feature3".into(), Vec::new()),
+                ]
+                .iter()
+                .cloned()
+                .collect::<HashMap<String, Vec<String>>>(),
             },
             build_result: BuildResult {
                 rustc_version: "rustc 2.0.0-nightly (000000000 1970-01-01)".into(),

src/utils/cargo_metadata.rs

@@ -77,6 +77,7 @@ pub(crate) struct Package {
     pub(crate) readme: Option<String>,
     pub(crate) keywords: Vec<String>,
     pub(crate) authors: Vec<String>,
+    pub(crate) features: HashMap<String, Vec<String>>,
 }
 
 impl Package {

src/web/crate_details.rs

@@ -45,6 +45,7 @@ pub struct CrateDetails {
     documented_items: Option<f32>,
     total_items_needing_examples: Option<f32>,
     items_with_examples: Option<f32>,
+    features: Option<Value>,
     /// Database id for this crate
     pub(crate) crate_id: i32,
     /// Database id for this release
@@ -103,6 +104,7 @@ 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,
@@ -187,6 +189,7 @@ impl CrateDetails {
             total_items: total_items.map(|v| v as f32),
             total_items_needing_examples: total_items_needing_examples.map(|v| v as f32),
             items_with_examples: items_with_examples.map(|v| v as f32),
+            features: krate.get("features"),
             crate_id,
             release_id,
         };

templates/rustdoc/topbar.html

@@ -226,7 +226,25 @@
                 </li>
             {%- endfor -%}
         </ul>
-    </li>
+    </li>{#
+    Display the features available in current build
+    #}
+    {% if 'krate' in __tera_context %}
+        <li class="pure-menu-item pure-menu-has-children">
+            <a href="#" class="pure-menu-link" aria-label="Platform">
+                <span class="title">Feature flags</span>
+            </a>
+
+            {# Build the dropdown list showing available features #}
+            <ul class="pure-menu-children">
+                {%- for feature in krate.features -%}
+                    <li class="pure-menu-item">
+                        <a href="#" class="pure-menu-link">{{ feature }}</a>
+                    </li>
+                {%- endfor -%}
+            </ul>
+        </li>
+    {%- endif -%}
 </ul>
 
 {%- include "header/topbar_end.html" -%}