feat: switch to user configured branch even when configuration is changed

DESCRIPTION

Branch switching wasn't possible in earlier versions. If user deploys
"master" branch first and then wants to switch to "pages" branch, they
would have to delete the Pages-managed copy of the repository to
re-initialize the repository.

This patch introduces changes to switch to user configured branch on
startup and at each repository update.

src/deploy.rs

@@ -45,7 +45,7 @@ async fn update(payload: web::Json<DeployEvent>) -> impl Responder {
     for page in SETTINGS.pages.iter() {
         if page.secret == payload.secret {
             web::block(|| {
-                page.fetch_upstream(&page.branch);
+                page.update();
             })
             .await
             .unwrap();

src/page.rs

@@ -38,25 +38,27 @@ impl Page {
         };
 
         let repo = Repository::open(&self.path).unwrap();
-        {
-            self._fetch_upstream(&repo, &self.branch);
-            let branch = repo
-                .find_branch(&format!("origin/{}", &self.branch), BranchType::Remote)
-                .unwrap();
-
-            let mut checkout_options = CheckoutBuilder::new();
-            checkout_options.force();
-
-            let tree = branch.get().peel(ObjectType::Tree).unwrap();
-
-            repo.checkout_tree(&tree, Some(&mut checkout_options))
-                .unwrap();
-
-            repo.set_head(branch.get().name().unwrap()).unwrap();
-        }
+        self._fetch_upstream(&repo, &self.branch);
+        self.deploy_branch(&repo);
         repo
     }
 
+    pub fn deploy_branch(&self, repo: &Repository) {
+        let branch = repo
+            .find_branch(&format!("origin/{}", &self.branch), BranchType::Remote)
+            .unwrap();
+
+        let mut checkout_options = CheckoutBuilder::new();
+        checkout_options.force();
+
+        let tree = branch.get().peel(ObjectType::Tree).unwrap();
+
+        repo.checkout_tree(&tree, Some(&mut checkout_options))
+            .unwrap();
+        repo.set_head(branch.get().name().unwrap()).unwrap();
+        info!("Deploying branch {}", self.branch);
+    }
+
     fn _fetch_upstream(&self, repo: &Repository, branch: &str) {
         let mut remote = repo.find_remote("origin").unwrap();
         remote.connect(Direction::Fetch).unwrap();
@@ -65,9 +67,10 @@ impl Page {
         remote.disconnect().unwrap();
     }
 
-    pub fn fetch_upstream(&self, branch: &str) {
+    pub fn update(&self) {
         let repo = self.create_repo();
-        self._fetch_upstream(&repo, branch);
+        self._fetch_upstream(&repo, &self.branch);
+        self.deploy_branch(&repo);
     }
 }
 
@@ -75,13 +78,22 @@ impl Page {
 mod tests {
     use super::*;
 
+    use git2::Branch;
+    use git2::Repository;
     use mktemp::Temp;
 
+    impl Page {
+        fn get_tree<'a>(&self, repo: &'a Repository) -> Branch<'a> {
+            repo.find_branch(&format!("origin/{}", &self.branch), BranchType::Remote)
+                .unwrap()
+        }
+    }
+
     #[actix_rt::test]
     async fn pages_works() {
         let tmp_dir = Temp::new_dir().unwrap();
         assert!(tmp_dir.exists(), "tmp directory successully created");
-        let page = Page {
+        let mut page = Page {
             secret: String::default(),
             repo: "https://github.com/mcaptcha/website".to_owned(),
             path: tmp_dir.to_str().unwrap().to_string(),
@@ -100,5 +112,15 @@ mod tests {
             Repository::open(tmp_dir.as_path()).is_ok(),
             "repository exists yet"
         );
+
+        let gh_pages = page.get_tree(&repo);
+        assert_eq!(
+            gh_pages.name().unwrap().as_ref().unwrap(),
+            &"origin/gh-pages"
+        );
+        page.branch = "master".to_string();
+        page.update();
+        let master = page.get_tree(&repo);
+        assert_eq!(master.name().unwrap().as_ref().unwrap(), &"origin/master");
     }
 }

src/settings.rs

@@ -104,7 +104,7 @@ impl Settings {
                     panic!("duplicate page onfiguration {:?} and {:?}", page, page2);
                 }
             }
-            page.fetch_upstream(&page.branch);
+            page.update();
         }
 
         Ok(settings)