init local repo

crates/signed_git/src/lib.rs

@@ -289,6 +289,57 @@ pub fn push_main(repo_path: &Path, base_url: &str, owner: &str, repo_id: &str) -
     Ok(())
 }
 
+/// Push every local branch and tag of the repository at `repo_path` to a
+/// grasp server (like `git push <url> --all --tags`), so an initialized
+/// repository's whole history is mirrored, not just `main`.
+pub fn push_all(repo_path: &Path, base_url: &str, owner: &str, repo_id: &str) -> Result<()> {
+    let url = format!("{base_url}/{owner}/{repo_id}.git");
+
+    let output = Command::new("git")
+        .arg("-C")
+        .arg(repo_path)
+        .args(["push", "--all", "--tags"])
+        .arg(&url)
+        .env("GIT_TERMINAL_PROMPT", "0")
+        .stderr(Stdio::piped())
+        .output()
+        .context("failed to spawn `git push`")?;
+
+    if !output.status.success() {
+        bail!(
+            "git push to {base_url} failed: {}",
+            String::from_utf8_lossy(&output.stderr).trim()
+        );
+    }
+    Ok(())
+}
+
+/// The earliest unique commit of the repository at `repo_path` (a root
+/// commit, like `git rev-list --max-parents=0 HEAD`), used as the NIP-34
+/// announcement's `euc` marker. `None` for a repository without commits.
+pub fn root_commit(repo_path: &Path) -> Result<Option<String>> {
+    let output = Command::new("git")
+        .arg("-C")
+        .arg(repo_path)
+        .args(["rev-list", "--max-parents=0", "HEAD"])
+        .env("GIT_TERMINAL_PROMPT", "0")
+        .stderr(Stdio::piped())
+        .output()
+        .context("failed to spawn `git rev-list`")?;
+
+    // An unborn HEAD (no commits yet) makes `rev-list` fail,
+    // there is no unique commit to report then.
+    if !output.status.success() {
+        return Ok(None);
+    }
+
+    Ok(String::from_utf8_lossy(&output.stdout)
+        .lines()
+        .next()
+        .map(str::to_owned)
+        .filter(|id| id.len() == 40))
+}
+
 /// Add `origin` pointing at `url` when the repository has no remote yet.
 /// No-op if `origin` already exists.
 pub fn ensure_origin(repo_path: &Path, url: &str) -> Result<()> {
@@ -1653,6 +1704,31 @@ mod tests {
         assert_eq!(found, expected);
     }
 
+    #[test]
+    fn root_commit_reports_the_first_ancestor() {
+        let (dir, repo) = fixture(&[("a.txt", b"one")]);
+        commit_all(&repo, "initial");
+
+        let dir = dir.path();
+        let root = root_commit(dir).expect("root").expect("commit");
+        assert_eq!(root.len(), 40);
+
+        // The root commit does not change when history grows.
+        std::fs::write(dir.join("b.txt"), b"two").expect("write");
+        commit_all(&repo, "second");
+        assert_eq!(
+            root_commit(dir).expect("root").as_deref(),
+            Some(root.as_str())
+        );
+    }
+
+    #[test]
+    fn root_commit_is_none_without_commits() {
+        let (_dir, repo) = fixture(&[("a.txt", b"one")]);
+        let workdir = repo.workdir().expect("workdir");
+        assert_eq!(root_commit(workdir).expect("root"), None);
+    }
+
     #[test]
     fn repo_ref_state_lists_branches_tags_and_head() {
         let (_dir, repo) = fixture(&[("a.txt", b"hello")]);