Fuller idea on how push can work.

src/git.rs

@@ -1,7 +1,7 @@
 use super::{config::PathConfig, path};
 use git2::{
-    Branch, BranchType, Commit, IndexAddOption, ObjectType, Reference, Remote, Repository,
+    Branch, BranchType, Commit, DiffOptions, Direction, IndexAddOption, ObjectType, Remote,
-    Signature,
+    Repository, Signature,
 };
 use path::ResPathBuf;
 use simplelog::{info, paris, warn};
@@ -61,7 +61,8 @@ impl fmt::Display for Error {
             Error::IOError(e) => write!(f, "{}", e),
             Error::InvalidBareRepo => write!(
                 f,
-                "Local repository should be a working directory. Did you manually initialize with `--bare`?"
+                "Local repository should be a working directory. Did you manually initialize with \
+                `--bare`?"
             ),
             Error::VarError(e) => write!(f, "{}", e),
         }
@@ -83,7 +84,7 @@ fn clone_or_init(pc: &PathConfig, expanded: &Path) -> Result<Repository> {
             );
             Ok(repo)
         }
-        Err(e) if (e.code() == git2::ErrorCode::NotFound || e.code() == git2::ErrorCode::Auth) => {
+        Err(e) if e.code() == git2::ErrorCode::NotFound || e.code() == git2::ErrorCode::Auth => {
             // TODO(jrpotter): Setup authentication callbacks so private
             // repositories work.
             // https://docs.rs/git2/0.13.25/git2/build/struct.RepoBuilder.html#example
@@ -169,9 +170,10 @@ fn find_package_files(pc: &PathConfig) -> Vec<ResPathBuf> {
 }
 
 pub fn stage(pc: &PathConfig, repo: &Repository) -> Result<()> {
-    let workdir = repo.workdir().ok_or(Error::InvalidBareRepo)?;
+    let workdir = validate_repo(&repo)?;
     let repo_files = find_repo_files(&workdir)?;
     let package_files = find_package_files(&pc);
+
     // Find all files in our repository that are no longer being referenced in
     // our primary config file. They should be removed from the repository.
     let lookup_files: HashSet<PathBuf> = package_files
@@ -181,7 +183,7 @@ pub fn stage(pc: &PathConfig, repo: &Repository) -> Result<()> {
     for repo_file in &repo_files {
         let relative = repo_file
             .resolved()
-            .strip_prefix(workdir)
+            .strip_prefix(&workdir)
             .expect("Relative git file could not be stripped properly.")
             .to_path_buf();
         if !lookup_files.contains(&relative) {
@@ -193,6 +195,7 @@ pub fn stage(pc: &PathConfig, repo: &Repository) -> Result<()> {
             }
         }
     }
+
     // Find all resolvable files in our primary config and copy them into the
     // repository.
     for package_file in &package_files {
@@ -203,6 +206,7 @@ pub fn stage(pc: &PathConfig, repo: &Repository) -> Result<()> {
         }
         fs::copy(package_file.resolved(), copy)?;
     }
+
     Ok(())
 }
 
@@ -211,65 +215,72 @@ pub fn stage(pc: &PathConfig, repo: &Repository) -> Result<()> {
 // ========================================
 
 pub fn push(pc: &PathConfig, repo: &mut Repository) -> Result<()> {
-    repo.workdir().ok_or(Error::InvalidBareRepo)?;
+    // First pull to make sure there are no conflicts when we push our changes.
-    // Switch to the new branch we want to work on. If the branch does not
+    // This will also perform validation and construct our local and remote
-    // exist, `set_head` will point to an unborn branch.
+    // environment.
-    // https://git-scm.com/docs/git-check-ref-format.
+    let _local_branch = pull(&pc, &repo)?;
-    repo.set_head(&format!("refs/heads/{}", pc.config.remote.branch))?;
-    // Establish our remote. If the remote already exists, re-configure it
-    // blindly to point to the appropriate url. Our results should now exist
-    // in a branch called `remotes/origin/<branch>`.
-    // https://git-scm.com/book/it/v2/Git-Basics-Working-with-Remotes
-    // TODO(jrpotter): Rebase against the remote.
     let mut remote = get_remote(&pc, &repo)?;
-    remote.fetch(&[&pc.config.remote.branch], None, None)?;
+
-    // Find the latest commit on our current branch. This could be empty if just
-    // having initialized the repository.
-    let parent_commit = match repo.head() {
-        Ok(head) => {
-            let obj = head
-                .resolve()?
-                .peel(ObjectType::Commit)?
-                .into_commit()
-                .map_err(|_| git2::Error::from_str("Couldn't find commit"))?;
-            vec![obj]
-        }
-        // An unborn branch error is fired when first initializing the
-        // repository. Our first commit will create the branch.
-        Err(e) => match e.code() {
-            git2::ErrorCode::UnbornBranch => vec![],
-            _ => Err(e)?,
-        },
-    };
     // The index corresponds to our staging area. We add all files and write out
     // to a tree. The resulting tree can be found using `git ls-tree <oid>`.
     // https://git-scm.com/book/en/v2/Git-Internals-Git-Objects
     let mut index = repo.index()?;
     index.add_all(["."].iter(), IndexAddOption::DEFAULT, None)?;
+    let diff_stats = repo
+        .diff_index_to_workdir(
+            Some(&index),
+            Some(
+                DiffOptions::new()
+                    .include_untracked(true)
+                    .include_unreadable(true),
+            ),
+        )?
+        .stats()?;
+    if diff_stats.files_changed() == 0
+        && diff_stats.insertions() == 0
+        && diff_stats.deletions() == 0
+    {
+        info!("Nothing to push. Have you run `homesync stage`?");
+        return Ok(());
+    }
+
+    let signature = get_signature(&pc)?;
+    // Retrieve the latest commit before writing to the object database.
+    let parent_commit = get_commit(&repo)?;
     let index_oid = index.write_tree()?;
     let index_tree = repo.find_tree(index_oid)?;
-    // Stash any of our changes. We will first fetch from the remote and then
+    info!("Writing index to tree `{}`.", index_oid);
-    // apply our changes on top of it.
+
-    // TODO(jrpotter): Add user and email to config. Remove init comamnd.
+    // Commit our changes and push them to our remote.
-    // TODO(jrpotter): Cannot stash changes with no initial commit.
+    let refspec = format!("refs/heads/{}", &pc.config.remote.branch);
-    let signature = Signature::now("homesync", "robot@homesync.org")?;
+    repo.commit(
-    let commit_oid = repo.commit(
+        Some(&refspec),
-        Some("HEAD"),
         &signature,
         &signature,
-        // TODO(jrpotter): See how many previous pushes were made.
+        // TODO(jrpotter): Come up with a more useful message.
         "homesync push",
         &index_tree,
-        // iter/collect to collect an array of references.
+        &[&parent_commit],
-        &parent_commit.iter().collect::<Vec<_>>()[..],
     )?;
-    let _commit = repo.find_commit(commit_oid)?;
+    remote.connect(Direction::Push)?;
+    remote.push(&[&format!("{r}:{r}", r = refspec)], None)?;
+    info!(
+        "Pushed changes to remote `{}/{}`.",
+        &pc.config.remote.name, &pc.config.remote.branch
+    );
+
     Ok(())
 }
 
-pub fn pull(pc: &PathConfig, repo: &Repository) -> Result<()> {
+pub fn pull<'repo>(pc: &PathConfig, repo: &'repo Repository) -> Result<Branch<'repo>> {
     validate_repo(&repo)?;
 
+    // Establish our remote. If the remote already exists, re-configure it
+    // blindly to point to the appropriate url. Our results should now exist
+    // in a branch called `remotes/origin/<branch>`.
+    // https://git-scm.com/book/it/v2/Git-Basics-Working-with-Remotes
+    // TODO(jrpotter): Configure our remote to point to the same URL mentioned
+    // in our config.
     let mut remote = get_remote(&pc, &repo)?;
     remote.fetch(&[&pc.config.remote.branch], None, None)?;
     let remote_branch_name = format!("{}/{}", &pc.config.remote.name, &pc.config.remote.branch);
@@ -282,6 +293,9 @@ pub fn pull(pc: &PathConfig, repo: &Repository) -> Result<()> {
     // available. These should be rebased relative to remote (our upstream).
     // 2. Our repository has been initialized in an empty state. The branch we
     // are interested in is unborn, so we can just copy the branch from remote.
+    //
+    // TODO(jrpotter): If changes are available, need to stage them and then
+    // reapply.
     let remote_ref = repo.reference_to_annotated_commit(remote_branch.get())?;
     if let Ok(local_branch) = repo.find_branch(&pc.config.remote.branch, BranchType::Local) {
         let local_ref = repo.reference_to_annotated_commit(local_branch.get())?;
@@ -289,28 +303,33 @@ pub fn pull(pc: &PathConfig, repo: &Repository) -> Result<()> {
         repo.rebase(Some(&local_ref), Some(&remote_ref), None, None)?
             .finish(Some(&signature))?;
         info!("Rebased local branch onto `{}`.", remote_branch_name);
+        Ok(local_branch)
     } else {
+        let local_branch =
             repo.branch_from_annotated_commit(&pc.config.remote.branch, &remote_ref, false)?;
         info!("Created new local branch from `{}`.", remote_branch_name);
+        Ok(local_branch)
     }
-
-    Ok(())
 }
 
 // ========================================
 // Utility
 // ========================================
 
-/// Generate a new signature at the current time.
-fn get_signature(pc: &PathConfig) -> Result<Signature> {
-    Ok(Signature::now(&pc.config.user.name, &pc.config.user.email)?)
-}
-
 /// Verify the repository we are working in supports the operations we want to
 /// apply to it.
-fn validate_repo(repo: &Repository) -> Result<()> {
+fn validate_repo(repo: &Repository) -> Result<PathBuf> {
-    repo.workdir().ok_or(Error::InvalidBareRepo)?;
+    Ok(repo.workdir().ok_or(Error::InvalidBareRepo)?.to_path_buf())
-    Ok(())
+}
+
+/// Return the latest commit off of HEAD.
+fn get_commit(repo: &Repository) -> Result<Commit> {
+    Ok(repo
+        .head()?
+        .resolve()?
+        .peel(ObjectType::Commit)?
+        .into_commit()
+        .map_err(|_| git2::Error::from_str("Couldn't find commit"))?)
 }
 
 /// Create or retrieve the remote specified within our configuration.
@@ -332,23 +351,7 @@ fn get_remote<'repo>(pc: &PathConfig, repo: &'repo Repository) -> Result<Remote<
     Ok(repo.find_remote(&pc.config.remote.name)?)
 }
 
-/// Finds the latest commit relative to HEAD.
+/// Generate a new signature at the current time.
-///
+fn get_signature(pc: &PathConfig) -> Result<Signature> {
-/// You should probably switch branches (refer to `switch_branch`) before
+    Ok(Signature::now(&pc.config.user.name, &pc.config.user.email)?)
-/// calling this function.
-fn get_head_commit(repo: &Repository) -> Result<Option<Commit>> {
-    match repo.head() {
-        Ok(head) => {
-            let obj = head
-                .resolve()?
-                .peel(ObjectType::Commit)?
-                .into_commit()
-                .map_err(|_| git2::Error::from_str("Couldn't find commit"))?;
-            Ok(Some(obj))
-        }
-        Err(e) => match e.code() {
-            git2::ErrorCode::UnbornBranch => Ok(None),
-            _ => Err(e)?,
-        },
-    }
 }