Add commit example

examples/commit.rs

@@ -0,0 +1,36 @@
+use git2::{Error, ErrorCode, Repository, Signature};
+
+fn main() -> Result<(), Error> {
+    let repository = Repository::open(".")?;
+
+    // We will commit the content of the index
+    let mut index = repository.index()?;
+    let tree_oid = index.write_tree()?;
+    let tree = repository.find_tree(tree_oid)?;
+
+    let parent_commit = match repository.revparse_single("HEAD") {
+        Ok(obj) => Some(obj.into_commit().unwrap()),
+        // First commit so no parent commit
+        Err(e) if e.code() == ErrorCode::NotFound => None,
+        Err(e) => return Err(e),
+    };
+
+    let mut parents = Vec::new();
+    if parent_commit.is_some() {
+        parents.push(parent_commit.as_ref().unwrap());
+    }
+
+    let signature = Signature::now("username", "[email protected]")?;
+    let commit_oid = repository.commit(
+        Some("HEAD"),
+        &signature,
+        &signature,
+        "Commit message",
+        &tree,
+        &parents[..],
+    )?;
+
+    let _commit = repository.find_commit(commit_oid)?;
+
+    Ok(())
+}