Show badge for latest version build status on crate list pages

If the latest version builds on any stable version, show that it
builds on stable. If not and it builds on any beta version, show
that. If not and it builds on any nightly version, show
that. Otherwise, don't show any badge.

app/components/badge-build-info.js

@@ -0,0 +1,41 @@
+import Ember from 'ember';
+
+import { formatDay } from 'cargo/helpers/format-day';
+
+export default Ember.Component.extend({
+    tagName: 'span',
+    classNames: ['build_info'],
+
+    build_info: Ember.computed('crate.max_build_info_stable', 'crate.max_build_info_beta', 'crate.max_build_info_nightly', function() {
+        if (this.get('crate.max_build_info_stable')) {
+            return 'stable';
+        } else if (this.get('crate.max_build_info_beta')) {
+            return 'beta';
+        } else if (this.get('crate.max_build_info_nightly')) {
+            return 'nightly';
+        } else {
+            return null;
+        }
+    }),
+    color: Ember.computed('build_info', function() {
+        if (this.get('build_info') === 'stable') {
+            return 'brightgreen';
+        } else if (this.get('build_info') === 'beta') {
+            return 'yellow';
+        } else {
+            return 'orange';
+        }
+    }),
+    version_display: Ember.computed('build_info', 'crate.max_build_info_stable', 'crate.max_build_info_beta', 'crate.max_build_info_nightly', function() {
+        if (this.get('build_info') === 'stable') {
+            return this.get('crate.max_build_info_stable');
+        } else if (this.get('build_info') === 'beta') {
+            return formatDay(this.get('crate.max_build_info_beta'));
+        } else {
+            return formatDay(this.get('crate.max_build_info_nightly'));
+        }
+    }),
+    version_for_shields: Ember.computed('version_display', function() {
+        return this.get('version_display').replace(/-/g, '--');
+    }),
+});

app/models/crate.js

@@ -17,6 +17,9 @@ export default DS.Model.extend({
     documentation: DS.attr('string'),
     repository: DS.attr('string'),
     exact_match: DS.attr('boolean'),
+    max_build_info_nightly: DS.attr('date'),
+    max_build_info_beta: DS.attr('date'),
+    max_build_info_stable: DS.attr('string'),
 
     versions: DS.hasMany('versions', { async: true }),
     badges: DS.attr(),

app/templates/components/badge-build-info.hbs

@@ -0,0 +1,6 @@
+{{#if build_info}}
+<img
+    src="https://img.shields.io/badge/builds_on-{{ version_for_shields }}-{{color}}.svg"
+    alt="Known to build on {{ build_info }} {{ version_display }}"
+    title="Known to build on {{ build_info }} {{ version_display }}" />
+{{/if}}

app/templates/components/crate-row.hbs

@@ -11,6 +11,7 @@
         {{#each crate.annotated_badges as |badge|}}
             {{component badge.component_name badge=badge data-test-badge=badge.badge_type}}
         {{/each}}
+        {{badge-build-info crate=crate}}
     </div>
     <div class='summary' data-test-description>
         <span class='small'>

src/krate/metadata.rs

@@ -40,7 +40,7 @@ pub fn summary(req: &mut Request) -> CargoResult<Response> {
             .map(|versions| Version::max(versions.into_iter().map(|v| v.num)))
             .zip(krates)
             .map(|(max_version, krate)| {
-                Ok(krate.minimal_encodable(&max_version, None, false, None))
+                Ok(krate.minimal_encodable(&max_version, None, false, None, None))
             })
             .collect()
     };
@@ -156,6 +156,7 @@ pub fn show(req: &mut Request) -> CargoResult<Response> {
             Some(badges),
             false,
             recent_downloads,
+            None,
         ),
         versions: versions
             .into_iter()

src/krate/mod.rs

@@ -9,7 +9,7 @@ use url::Url;
 use app::App;
 use util::{human, CargoResult};
 
-use views::EncodableBadge;
+use views::{EncodableBadge, EncodableMaxVersionBuildInfo};
 use models::{Badge, Category, CrateOwner, Keyword, NewCrateOwnerInvitation, Owner, OwnerKind,
              ReverseDependency, User, Version};
 
@@ -113,6 +113,9 @@ pub struct EncodableCrate {
     pub repository: Option<String>,
     pub links: CrateLinks,
     pub exact_match: bool,
+    pub max_build_info_stable: Option<String>,
+    pub max_build_info_beta: Option<String>,
+    pub max_build_info_nightly: Option<String>,
 }
 
 #[derive(Serialize, Deserialize, Debug)]
@@ -315,6 +318,7 @@ impl Crate {
         badges: Option<Vec<Badge>>,
         exact_match: bool,
         recent_downloads: Option<i64>,
+        max_build_info: Option<EncodableMaxVersionBuildInfo>,
     ) -> EncodableCrate {
         self.encodable(
             max_version,
@@ -324,6 +328,7 @@ impl Crate {
             badges,
             exact_match,
             recent_downloads,
+            max_build_info,
         )
     }
 
@@ -337,6 +342,7 @@ impl Crate {
         badges: Option<Vec<Badge>>,
         exact_match: bool,
         recent_downloads: Option<i64>,
+        max_build_info: Option<EncodableMaxVersionBuildInfo>,
     ) -> EncodableCrate {
         let Crate {
             name,
@@ -357,6 +363,7 @@ impl Crate {
         let category_ids = categories.map(|cats| cats.iter().map(|cat| cat.slug.clone()).collect());
         let badges = badges.map(|bs| bs.into_iter().map(|b| b.encodable()).collect());
         let documentation = Crate::remove_blacklisted_documentation_urls(documentation);
+        let max_build_info = max_build_info.unwrap_or_else(EncodableMaxVersionBuildInfo::default);
 
         EncodableCrate {
             id: name.clone(),
@@ -370,6 +377,9 @@ impl Crate {
             categories: category_ids,
             badges: badges,
             max_version: max_version.to_string(),
+            max_build_info_stable: max_build_info.stable,
+            max_build_info_beta: max_build_info.beta,
+            max_build_info_nightly: max_build_info.nightly,
             documentation: documentation,
             homepage: homepage,
             exact_match: exact_match,
@@ -606,6 +616,9 @@ mod tests {
             downloads: 0,
             recent_downloads: None,
             max_version: "".to_string(),
+            max_build_info_stable: None,
+            max_build_info_beta: None,
+            max_build_info_nightly: None,
             description: None,
             homepage: None,
             documentation: None,

src/krate/publish.rs

@@ -181,7 +181,7 @@ pub fn publish(req: &mut Request) -> CargoResult<Response> {
             warnings: Warnings<'a>,
         }
         Ok(req.json(&R {
-            krate: krate.minimal_encodable(&max_version, None, false, None),
+            krate: krate.minimal_encodable(&max_version, None, false, None, None),
             warnings: warnings,
         }))
     })

src/krate/search.rs

@@ -10,7 +10,7 @@ use user::RequestUser;
 use util::{CargoResult, RequestUtils};
 
 use views::EncodableCrate;
-use models::{Badge, Crate, OwnerKind, Version};
+use models::{Badge, BuildInfo, Crate, OwnerKind, Version};
 use schema::*;
 
 use super::{canon_crate_name, ALL_COLUMNS};
@@ -183,28 +183,46 @@ pub fn search(req: &mut Request) -> CargoResult<Response> {
         .load::<Version>(&*conn)?
         .grouped_by(&crates)
         .into_iter()
-        .map(|versions| Version::max(versions.into_iter().map(|v| v.num)));
+        .map(|versions| {
+            versions
+                .into_iter()
+                .max_by(Version::semantically_newest_first)
+                .unwrap()
+        })
+        .collect::<Vec<_>>();
+
+    let build_infos = BuildInfo::belonging_to(&versions)
+        .filter(build_info::passed.eq(true))
+        .select(::version::build_info::BUILD_INFO_FIELDS)
+        .load::<BuildInfo>(&*conn)?
+        .grouped_by(&versions)
+        .into_iter()
+        .map(BuildInfo::max);
 
     let crates = versions
+        .into_iter()
         .zip(crates)
         .zip(perfect_matches)
         .zip(recent_downloads)
+        .zip(build_infos)
         .map(
-            |(((max_version, krate), perfect_match), recent_downloads)| {
+            |((((max_version, krate), perfect_match), recent_downloads), build_info)| {
+                let build_info = build_info?;
                 // FIXME: If we add crate_id to the Badge enum we can eliminate
                 // this N+1
                 let badges = badges::table
                     .filter(badges::crate_id.eq(krate.id))
                     .load::<Badge>(&*conn)?;
                 Ok(krate.minimal_encodable(
-                    &max_version,
+                    &max_version.num,
                     Some(badges),
                     perfect_match,
                     Some(recent_downloads),
+                    Some(build_info.encode()),
                 ))
             },
         )
-        .collect::<Result<_, ::diesel::result::Error>>()?;
+        .collect::<CargoResult<_>>()?;
 
     #[derive(Serialize)]
     struct R {

src/models/mod.rs

@@ -9,6 +9,7 @@ pub use owner::{CrateOwner, NewTeam, Owner, OwnerKind, Rights, Team};
 pub use user::{Email, NewUser, User};
 pub use token::ApiToken;
 pub use version::{NewVersion, Version};
+pub use version::build_info::BuildInfo;
 
 mod category;
 mod keyword;

src/version/build_info.rs

@@ -1,4 +1,8 @@
+use std::str::FromStr;
+
+use chrono::{DateTime, NaiveDate, Utc};
 use conduit::{Request, Response};
+use semver;
 use serde_json;
 
 use app::RequestApp;
@@ -8,7 +12,8 @@ use owner::rights;
 use user::RequestUser;
 use util::{human, CargoResult, RequestUtils};
 use version::version_and_crate;
-use views::EncodableVersionBuildInfoUpload;
+use views::{EncodableMaxVersionBuildInfo, EncodableVersionBuildInfoUpload,
+            ParsedRustChannelVersion};
 
 use schema::*;
 
@@ -24,6 +29,80 @@ pub struct BuildInfo {
     pub passed: bool,
 }
 
+/// The columns to select from the `build_info` table. The table also stores `created_at` and
+/// `updated_at` metadata for each row, but we're not displaying those anywhere so we're not
+/// bothering to select them.
+pub const BUILD_INFO_FIELDS: (
+    build_info::version_id,
+    build_info::rust_version,
+    build_info::target,
+    build_info::passed,
+) = (
+    build_info::version_id,
+    build_info::rust_version,
+    build_info::target,
+    build_info::passed,
+);
+
+#[derive(Debug)]
+/// The maximum version of Rust from each channel that a crate version successfully builds with.
+/// Used for summarizing this information in badge form on crate list pages.
+pub struct MaxBuildInfo {
+    pub stable: Option<semver::Version>,
+    pub beta: Option<NaiveDate>,
+    pub nightly: Option<NaiveDate>,
+}
+
+impl MaxBuildInfo {
+    /// Encode stable semver number as a string and beta and nightly as times appropriate for
+    /// JSON.
+    pub fn encode(self) -> EncodableMaxVersionBuildInfo {
+        fn naive_date_to_rfc3339(date: NaiveDate) -> String {
+            DateTime::<Utc>::from_utc(date.and_hms(0, 0, 0), Utc).to_rfc3339()
+        }
+
+        EncodableMaxVersionBuildInfo {
+            stable: self.stable.map(|v| v.to_string()),
+            beta: self.beta.map(naive_date_to_rfc3339),
+            nightly: self.nightly.map(naive_date_to_rfc3339),
+        }
+    }
+}
+
+impl BuildInfo {
+    /// From a set of build information data, Find the largest or latest Rust versions that we know
+    /// about for each channel. Stable uses the largest semver version number; beta and nightly use
+    /// the latest date.
+    pub fn max<I>(build_infos: I) -> CargoResult<MaxBuildInfo>
+    where
+        I: IntoIterator<Item = BuildInfo>,
+    {
+        let build_infos = build_infos
+            .into_iter()
+            .map(|bi| ParsedRustChannelVersion::from_str(&bi.rust_version))
+            .collect::<Result<Vec<_>, _>>()?;
+
+        let stable = build_infos
+            .iter()
+            .filter_map(ParsedRustChannelVersion::as_stable)
+            .max();
+        let beta = build_infos
+            .iter()
+            .filter_map(ParsedRustChannelVersion::as_beta)
+            .max();
+        let nightly = build_infos
+            .iter()
+            .filter_map(ParsedRustChannelVersion::as_nightly)
+            .max();
+
+        Ok(MaxBuildInfo {
+            stable: stable.cloned(),
+            beta: beta.cloned(),
+            nightly: nightly.cloned(),
+        })
+    }
+}
+
 /// Handles the `POST /crates/:crate_id/:version/build_info` route for the
 /// `cargo publish-build-info` command to report on which versions of Rust
 /// a crate builds with.

src/version/metadata.rs

@@ -106,12 +106,7 @@ pub fn build_info(req: &mut Request) -> CargoResult<Response> {
     let conn = req.db_conn()?;
 
     let build_infos = BuildInfo::belonging_to(&version)
-        .select((
-            build_info::version_id,
-            build_info::rust_version,
-            build_info::target,
-            build_info::passed,
-        ))
+        .select(::version::build_info::BUILD_INFO_FIELDS)
         .load(&*conn)?;
 
     let mut encodable_build_info = EncodableVersionBuildInfo::default();

src/version/mod.rs

@@ -170,6 +170,11 @@ impl Version {
 
         Ok(())
     }
+
+    /// Orders SemVer numbers so that "higher" version numbers appear first.
+    pub fn semantically_newest_first(a: &Self, b: &Self) -> ::std::cmp::Ordering {
+        b.num.cmp(&a.num)
+    }
 }
 
 impl NewVersion {