Add support for reverse dependencies.

app/models/crate.js

@@ -20,4 +20,5 @@ export default DS.Model.extend({
     owners: DS.hasMany('users', {async: true}),
     version_downloads: DS.hasMany('version-download', {async: true}),
     keywords: DS.hasMany('keywords', {async: true}),
+    reverse_dependencies: DS.hasMany('reverse-dependency', {async: true}),
 });

app/models/reverse-dependency.js

@@ -0,0 +1,3 @@
+import Dependency from 'cargo/models/dependency';
+
+export default Dependency;

app/router.js

@@ -14,6 +14,7 @@ Router.map(function() {
   this.resource('crate', { path: '/crates/*crate_id' }, function() {
     this.route('download');
     this.route('versions');
+    this.route('reverse_dependencies');
   });
   this.route('me', function() {
     this.route('crates');

app/routes/crate/reverse-dependencies.js

@@ -0,0 +1,20 @@
+import Ember from 'ember';
+import Crate from 'cargo/models/crate';
+
+export default Ember.Route.extend({
+    afterModel: function(data) {
+      console.log("afterModel");
+        if (data instanceof Crate) {
+            return data.get('reverse_dependencies');
+        } else {
+            return data.crate.get('reverse_dependencies');
+        }
+    },
+
+    setupController: function(controller, data) {
+        if (data instanceof Crate) {
+            data = {crate: data, reverse_dependencies: null};
+        }
+        this._super(controller, data.crate);
+    },
+});

app/templates/crate/reverse-dependencies.hbs

@@ -0,0 +1,24 @@
+<div class='all-versions-back'>
+    {{#link-to 'crate' this}}&#11013; Back to Main Page{{/link-to}}
+</div>
+
+<div class='info'>
+    <span class='small'>
+        All <span class='num'>{{ reverse_dependencies.length }}</span>
+        reverse dependencies of <span class='num'>{{ name }}</span>
+    </span>
+</div>
+
+<div id='crate-all-reverse-dependencies' class='white-rows'>
+    {{#each model.reverse_dependencies}}
+        <div class='row'>
+          <div>
+            {{#link-to 'crate' crate_id}}{{crate_id}}{{/link-to}} requires {{req}}
+                {{#link-to 'crate' this}}{{ num }}{{/link-to}}
+            </div>
+            {{#link-to 'crate' this class='arrow'}}
+                <img src="/assets/right-arrow-all-versions.png"/>
+            {{/link-to}}
+        </div>
+    {{/each}}
+</div>

src/krate.rs

@@ -17,6 +17,7 @@ use url::{mod, Url};
 use {Model, User, Keyword, Version};
 use app::{App, RequestApp};
 use db::{Connection, RequestTransaction};
+use dependency::{Dependency, EncodableDependency};
 use download::{VersionDownload, EncodableVersionDownload};
 use git;
 use keyword::EncodableKeyword;
@@ -68,6 +69,7 @@ pub struct CrateLinks {
     pub version_downloads: String,
     pub versions: Option<String>,
     pub owners: Option<String>,
+    pub reverse_dependencies: String,
 }
 
 impl Crate {
@@ -253,6 +255,7 @@ impl Crate {
                 version_downloads: format!("/api/v1/crates/{}/downloads", name),
                 versions: versions_link,
                 owners: Some(format!("/api/v1/crates/{}/owners", name)),
+                reverse_dependencies: format!("/api/v1/crates/{}/reverse_dependencies", name)
             },
         }
     }
@@ -333,6 +336,22 @@ impl Crate {
         let rows = try!(stmt.query(&[&self.id]));
         Ok(rows.map(|r| Model::from_row(&r)).collect())
     }
+
+    /// Returns (dependency, dependent crate name)
+    pub fn reverse_dependencies(&self, conn: &Connection) -> CargoResult<Vec<(Dependency, String)>> {
+        let stmt = try!(conn.prepare("SELECT dependencies.*,
+                                             crates.name AS crate_name
+                                      FROM dependencies
+                                      INNER JOIN versions
+                                        ON versions.id = dependencies.version_id
+                                      INNER JOIN crates
+                                        ON crates.id = versions.crate_id
+                                      WHERE dependencies.crate_id = $1
+                                        AND versions.num = crates.max_version"));
+        Ok(try!(stmt.query(&[&self.id])).map(|r| {
+            (Model::from_row(&r), r.get("crate_name"))
+        }).collect())
+    }
 }
 
 impl Model for Crate {
@@ -860,3 +879,18 @@ fn modify_owners(req: &mut Request, add: bool) -> CargoResult<Response> {
     struct R { ok: bool }
     Ok(req.json(&R{ ok: true }))
 }
+
+pub fn reverse_dependencies(req: &mut Request) -> CargoResult<Response> {
+    let name = &req.params()["crate_id"];
+    let conn = try!(req.tx());
+    let krate = try!(Crate::find_by_name(conn, name.as_slice()));
+    let tx = try!(req.tx());
+    let rev_deps = try!(krate.reverse_dependencies(tx));
+    let rev_deps = rev_deps.into_iter().map(|(dep, crate_name)| {
+        dep.encodable(crate_name.as_slice())
+    }).collect();
+
+    #[deriving(Encodable)]
+    struct R { reverse_dependencies: Vec<EncodableDependency> }
+    Ok(req.json(&R{ reverse_dependencies: rev_deps }))
+}

src/lib.rs

@@ -89,6 +89,7 @@ pub fn middleware(app: Arc<App>) -> MiddlewareBuilder {
     api_router.delete("/crates/:crate_id/owners", C(krate::remove_owners));
     api_router.delete("/crates/:crate_id/:version/yank", C(version::yank));
     api_router.put("/crates/:crate_id/:version/unyank", C(version::unyank));
+    api_router.get("/crates/:crate_id/reverse_dependencies", C(krate::reverse_dependencies));
     api_router.get("/versions", C(version::index));
     api_router.get("/versions/:version_id", C(version::show));
     api_router.get("/keywords", C(keyword::index));

src/tests/all.rs

@@ -24,6 +24,7 @@ use conduit_test::MockRequest;
 use cargo_registry::app::App;
 use cargo_registry::db::{mod, RequestTransaction};
 use cargo_registry::{User, Crate, Version, Keyword};
+use cargo_registry::util::CargoResult;
 
 macro_rules! t( ($e:expr) => (
     match $e {
@@ -213,8 +214,14 @@ fn mock_user(req: &mut Request, u: User) -> User {
 }
 
 fn mock_crate(req: &mut Request, krate: Crate) -> Crate {
+    let (c, v) = mock_crate_vers(req, krate, &semver::Version::parse("1.0.0").unwrap());
+    v.unwrap();
+    c
+}
+fn mock_crate_vers(req: &mut Request, krate: Crate, v: &semver::Version)
+                   -> (Crate, CargoResult<Version>) {
     let user = req.extensions().find::<User>().unwrap();
-    let krate = Crate::find_or_insert(req.tx().unwrap(), krate.name.as_slice(),
+    let mut krate = Crate::find_or_insert(req.tx().unwrap(), krate.name.as_slice(),
                                       user.id, &krate.description,
                                       &krate.homepage,
                                       &krate.documentation,
@@ -224,10 +231,8 @@ fn mock_crate(req: &mut Request, krate: Crate) -> Crate {
                                       &krate.license).unwrap();
     Keyword::update_crate(req.tx().unwrap(), &krate,
                           krate.keywords.as_slice()).unwrap();
-    Version::insert(req.tx().unwrap(), krate.id,
-                    &semver::Version::parse("1.0.0").unwrap(),
-                    &HashMap::new(), &[]).unwrap();
-    return krate;
+    let v = krate.add_version(req.tx().unwrap(), v, &HashMap::new(), &[]);
+    (krate, v)
 }
 
 fn mock_keyword(req: &mut Request, name: &str) -> Keyword {

src/tests/krate.rs

@@ -32,6 +32,8 @@ struct CrateResponse { krate: EncodableCrate, versions: Vec<EncodableVersion> }
 #[deriving(Decodable)]
 struct Deps { dependencies: Vec<EncodableDependency> }
 #[deriving(Decodable)]
+struct RevDeps { reverse_dependencies: Vec<EncodableDependency> }
+#[deriving(Decodable)]
 struct Downloads { version_downloads: Vec<EncodableVersionDownload> }
 
 #[test]
@@ -504,7 +506,7 @@ fn dependencies() {
     let c1 = ::krate("foo");
     let c2 = ::krate("bar");
     middle.add(::middleware::MockUser(user.clone()));
-    middle.add(::middleware::MockDependency(c1.clone(), c2.clone()));
+    middle.add(::middleware::MockDependency(c1.clone(), "1.0.0", c2.clone()));
     let rel = format!("/api/v1/crates/{}/1.0.0/dependencies", c1.name);
     let mut req = MockRequest::new(conduit::Get, rel.as_slice());
     let mut response = ok_resp!(middle.call(&mut req));
@@ -700,3 +702,32 @@ fn bad_keywords() {
         ::json::<::Bad>(&mut response);
     }
 }
+
+#[test]
+fn reverse_dependencies() {
+    let (_b, _app, mut middle) = ::app();
+    let user = ::user("foo");
+    let c1 = ::krate("foo");
+    let c2 = ::krate("bar");
+    middle.add(::middleware::MockUser(user.clone()));
+    // multiple dependencies of c1 on c2, to detect we handle this
+    // correctly.
+    middle.add(::middleware::MockDependency(c1.clone(), "1.0.0", c2.clone()));
+    middle.add(::middleware::MockDependency(c1.clone(), "1.1.0", c2.clone()));
+
+    let rel = format!("/api/v1/crates/{}/reverse_dependencies", c2.name);
+    let mut req = MockRequest::new(conduit::Get, rel.as_slice());
+    let mut response = ok_resp!(middle.call(&mut req));
+    let deps = ::json::<RevDeps>(&mut response);
+    assert_eq!(deps.reverse_dependencies.len(), 1);
+    assert_eq!(deps.reverse_dependencies[0].crate_id.as_slice(), &*c1.name);
+    drop(req);
+
+    // c1 has no dependent crates.
+    let rel = format!("/api/v1/crates/{}/reverse_dependencies", c1.name);
+    let mut req = MockRequest::new(conduit::Get, rel.as_slice());
+    let mut response = ok_resp!(middle.call(&mut req));
+    let deps = ::json::<RevDeps>(&mut response);
+    assert_eq!(deps.reverse_dependencies.len(), 0);
+    drop(req);
+}

src/tests/middleware.rs

@@ -28,15 +28,19 @@ impl Middleware for MockCrate {
     }
 }
 
-pub struct MockDependency(pub Crate, pub Crate);
+pub struct MockDependency(pub Crate, pub &'static str, pub Crate);
 
 impl Middleware for MockDependency {
     fn before(&self, req: &mut Request) -> Result<(), Box<Show + 'static>> {
-        let MockDependency(ref a, ref b) = *self;
-        let crate_a = ::mock_crate(req, a.clone());
-        let crate_b = ::mock_crate(req, b.clone());
-        let va = crate_a.versions(req.tx().unwrap()).unwrap()[0].id;
-        Dependency::insert(req.tx().unwrap(), va, crate_b.id,
+        let MockDependency(ref a, version, ref b) = *self;
+        let vers = semver::Version::parse(version).unwrap();
+        let (_crate_a, va) = ::mock_crate_vers(req, a.clone(), &vers);
+
+        // don't panic on duplicate uploads
+        let (crate_b, _) = ::mock_crate_vers(req, b.clone(),
+                                             &semver::Version::parse("1.0.0").unwrap());
+
+        Dependency::insert(req.tx().unwrap(), va.unwrap().id, crate_b.id,
                            &semver::VersionReq::parse(">= 0").unwrap(),
                            Kind::Normal,
                            false, true, &[], &None).unwrap();