merge: blitz/spawn-v2 into spawn-v2/55-branches

crates/maestro-daemon/src/branches.rs

@@ -0,0 +1,167 @@
+//! `GET /api/branches` — local branches of one repository (#55).
+//!
+//! Spawning into a worktree on an *existing* branch needs to know which
+//! branches the repository has and which are taken: git refuses to check the
+//! same branch out in two worktrees at once. Each [`BranchInfo`] answers for
+//! one local branch — its name, whether it is the main checkout's HEAD, and
+//! which linked worktree (if any) holds it.
+//!
+//! Read-only, like [`crate::gitroot`]: two git probes (`for-each-ref`,
+//! `worktree list --porcelain`) with no write path anywhere. A path outside
+//! any repository yields an empty list rather than an error, matching how
+//! `/api/gitroot` reports "not a repository".
+
+use std::collections::HashMap;
+use std::path::{Path, PathBuf};
+use std::process::Command;
+
+use axum::extract::{Query, State};
+use axum::response::{IntoResponse, Response};
+use axum::Json;
+use maestro_protocol::BranchInfo;
+use serde::Deserialize;
+
+use crate::local_api::LocalApiState;
+
+/// Query string for `GET /api/branches`. Same `path` convention as
+/// `/api/dirs` and `/api/gitroot`: resolved against the daemon's home dir.
+#[derive(Debug, Deserialize)]
+pub struct BranchesQuery {
+    #[serde(default)]
+    pub path: String,
+}
+
+pub async fn handler(State(s): State<LocalApiState>, Query(q): Query<BranchesQuery>) -> Response {
+    let dir = crate::dirlist::resolve(&s.home_dir, &q.path);
+    Json(list(&dir)).into_response()
+}
+
+/// List the enclosing repository's local branches. Empty when `dir` is not
+/// inside a repository.
+pub fn list(dir: &Path) -> Vec<BranchInfo> {
+    let Some(root) = crate::gitroot::find_root(dir) else {
+        return Vec::new();
+    };
+    let worktrees = worktree_branches(&root);
+    // The first porcelain record is always the main checkout; its branch is
+    // the HEAD answer. Linked worktrees are the occupancy map.
+    let head_branch = worktrees.first().and_then(|(branch, _)| branch.clone());
+    let occupied: HashMap<&str, &Path> = worktrees
+        .iter()
+        .skip(1)
+        .filter_map(|(branch, path)| branch.as_deref().map(|b| (b, path.as_path())))
+        .collect();
+
+    branch_names(&root)
+        .into_iter()
+        .map(|name| BranchInfo {
+            is_head: head_branch.as_deref() == Some(name.as_str()),
+            worktree: occupied.get(name.as_str()).copied().map(Path::to_path_buf),
+            name,
+        })
+        .collect()
+}
+
+fn run_git(root: &Path, args: &[&str]) -> Option<String> {
+    let out = Command::new("git")
+        .arg("-C")
+        .arg(root)
+        .args(args)
+        .output()
+        .ok()?;
+    if !out.status.success() {
+        return None;
+    }
+    Some(String::from_utf8_lossy(&out.stdout).into_owned())
+}
+
+fn branch_names(root: &Path) -> Vec<String> {
+    run_git(
+        root,
+        &["for-each-ref", "refs/heads", "--format=%(refname:short)"],
+    )
+    .map(|out| {
+        out.lines()
+            .filter(|l| !l.is_empty())
+            .map(str::to_owned)
+            .collect()
+    })
+    .unwrap_or_default()
+}
+
+fn worktree_branches(root: &Path) -> Vec<(Option<String>, PathBuf)> {
+    let out = match run_git(root, &["worktree", "list", "--porcelain"]) {
+        Some(out) => out,
+        None => return Vec::new(),
+    };
+    parse_worktrees(&out)
+}
+
+/// Parse `git worktree list --porcelain` into `(branch, toplevel)` records,
+/// branch-less for detached/bare checkouts. Records are separated by blank
+/// lines; each `worktree` line starts a new one.
+fn parse_worktrees(out: &str) -> Vec<(Option<String>, PathBuf)> {
+    let mut result: Vec<(Option<String>, PathBuf)> = Vec::new();
+    let mut pending: Option<PathBuf> = None;
+    let mut branch: Option<String> = None;
+
+    for line in out.lines() {
+        if let Some(path) = line.strip_prefix("worktree ") {
+            if let Some(prev) = pending.take() {
+                result.push((branch.take(), prev));
+            }
+            pending = Some(PathBuf::from(path));
+        } else if let Some(b) = line.strip_prefix("branch ") {
+            branch = Some(b.trim_start_matches("refs/heads/").to_owned());
+        }
+    }
+    if let Some(path) = pending {
+        result.push((branch.take(), path));
+    }
+    result
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parses_main_and_linked_worktrees() {
+        let out = "\
+worktree /repos/maestro
+HEAD 0123abcd
+branch refs/heads/main
+
+worktree /repos/wt-feature
+HEAD 4567abcd
+branch refs/heads/spawn-v2
+
+";
+        assert_eq!(
+            parse_worktrees(out),
+            vec![
+                (Some("main".into()), PathBuf::from("/repos/maestro")),
+                (Some("spawn-v2".into()), PathBuf::from("/repos/wt-feature")),
+            ]
+        );
+    }
+
+    #[test]
+    fn detached_head_yields_no_branch() {
+        let out = "\
+worktree /repos/detached
+HEAD 0123abcd
+detached
+
+";
+        assert_eq!(
+            parse_worktrees(out),
+            vec![(None, PathBuf::from("/repos/detached"))]
+        );
+    }
+
+    #[test]
+    fn empty_output_yields_no_records() {
+        assert!(parse_worktrees("").is_empty());
+    }
+}

crates/maestro-daemon/src/lib.rs

@@ -9,6 +9,7 @@
 
 pub mod activity;
 pub mod attach;
+pub mod branches;
 pub mod cli;
 pub mod config;
 pub mod dirlist;

crates/maestro-daemon/src/local_api.rs

@@ -48,6 +48,7 @@ pub fn router(state: LocalApiState) -> Router {
         .route(routes::RECENT_DIRS, get(recent_dirs))
         .route(routes::PROJECTS, get(projects))
         .route(routes::GITROOT, get(git_root))
+        .route(routes::BRANCHES, get(crate::branches::handler))
         .route(routes::INFO, get(daemon_info))
         .route(routes::EVENTS, any(events_ws))
         .route(routes::patterns::ATTACH, any(attach_ws))

crates/maestro-daemon/tests/branches.rs

@@ -0,0 +1,141 @@
+//! Integration tests for `GET /api/branches` (#55).
+
+mod common;
+
+use std::net::{Ipv4Addr, SocketAddr};
+use std::path::Path;
+use std::process::Command;
+use std::sync::Arc;
+
+use common::DaemonFixture;
+use maestro_daemon::local_api;
+use tokio::net::TcpListener;
+use tokio::sync::oneshot;
+
+struct Harness {
+    addr: SocketAddr,
+    _shutdown: oneshot::Sender<()>,
+    _fx: DaemonFixture,
+}
+
+async fn spawn() -> Harness {
+    let fx = DaemonFixture::new();
+    let presets = maestro_config::SpawnSection::default().resolve().unwrap();
+    let router = local_api::router(local_api::state_for(
+        fx.manager.clone(),
+        "naps-laptop",
+        "/home/test",
+        presets,
+        Arc::new(maestro_daemon::projects::ProjectScanner::disabled()),
+    ));
+    let listener = TcpListener::bind(SocketAddr::from((Ipv4Addr::LOCALHOST, 0)))
+        .await
+        .unwrap();
+    let addr = listener.local_addr().unwrap();
+    let (tx, rx) = oneshot::channel::<()>();
+    tokio::spawn(async move {
+        let _ = axum::serve(listener, router)
+            .with_graceful_shutdown(async move {
+                let _ = rx.await;
+            })
+            .await;
+    });
+    Harness {
+        addr,
+        _shutdown: tx,
+        _fx: fx,
+    }
+}
+
+fn git(repo: &Path, args: &[&str]) {
+    let out = Command::new("git")
+        .arg("-C")
+        .arg(repo)
+        .args(args)
+        .output()
+        .unwrap();
+    assert!(
+        out.status.success(),
+        "git {args:?} failed: {}",
+        String::from_utf8_lossy(&out.stderr)
+    );
+}
+
+/// A real repo on `main` with a second branch `feature`, and a linked
+/// worktree at `<tmp>/wt-feature` holding `feature`.
+fn repo_with_occupied_branch() -> tempfile::TempDir {
+    let tmp = tempfile::tempdir().unwrap();
+    let repo = tmp.path();
+    git(repo, &["init", "-q", "-b", "main"]);
+    git(
+        repo,
+        &[
+            "-c",
+            "user.email=t@t",
+            "-c",
+            "user.name=t",
+            "commit",
+            "-qm",
+            "init",
+            "--allow-empty",
+        ],
+    );
+    git(repo, &["branch", "feature"]);
+    let wt = tmp.path().join("wt-feature");
+    git(repo, &["worktree", "add", &wt.to_string_lossy(), "feature"]);
+    tmp
+}
+
+async fn get_branches(addr: SocketAddr, path: &Path) -> Vec<maestro_protocol::BranchInfo> {
+    reqwest::get(format!(
+        "http://{addr}/api/branches?path={}",
+        urlencoding::encode(&path.to_string_lossy())
+    ))
+    .await
+    .unwrap()
+    .json()
+    .await
+    .unwrap()
+}
+
+/// #55: every local branch is listed; the main checkout's HEAD reports
+/// `is_head`, and a branch held by a linked worktree reports that worktree's
+/// path so the client can explain why the entry is disabled.
+#[tokio::test]
+async fn branches_lists_local_branches_and_worktree_occupancy() {
+    let tmp = repo_with_occupied_branch();
+    let h = spawn().await;
+
+    let mut branches = get_branches(h.addr, tmp.path()).await;
+    branches.sort_by(|a, b| a.name.cmp(&b.name));
+
+    assert_eq!(
+        branches.iter().map(|b| b.name.as_str()).collect::<Vec<_>>(),
+        ["feature", "main"]
+    );
+
+    let main = branches.iter().find(|b| b.name == "main").unwrap();
+    assert!(main.is_head, "main is the main checkout's HEAD");
+    assert_eq!(main.worktree, None, "HEAD occupancy rides `is_head`");
+
+    let feature = branches.iter().find(|b| b.name == "feature").unwrap();
+    assert!(!feature.is_head);
+    assert_eq!(
+        feature.worktree.as_deref(),
+        Some(tmp.path().join("wt-feature").as_path()),
+        "the linked worktree holding the branch must be reported"
+    );
+}
+
+/// #55: a path outside any repository is not an error — an empty list,
+/// matching how `/api/gitroot` reports "not a repository".
+#[tokio::test]
+async fn branches_returns_empty_for_a_path_outside_a_repository() {
+    let h = spawn().await;
+    let tmp = tempfile::tempdir().unwrap();
+    let plain = tmp.path().join("plain");
+    std::fs::create_dir_all(&plain).unwrap();
+
+    let branches = get_branches(h.addr, &plain).await;
+    assert!(branches.is_empty());
+}

crates/maestro-protocol/src/lib.rs

@@ -212,6 +212,21 @@ pub struct Project {
     pub last_command: Option<String>,
 }
 
+/// One local branch of a repository for `GET /api/branches` (#55). A client
+/// disables the entry when `is_head` is set or `worktree` is present — git
+/// refuses to check the same branch out in two worktrees at once.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct BranchInfo {
+    /// Short branch name (`main`, `feature/foo`).
+    pub name: String,
+    /// Whether this branch is the main checkout's current HEAD. The main
+    /// checkout's occupancy reports here rather than through `worktree`.
+    pub is_head: bool,
+    /// Toplevel path of the linked worktree holding this branch, if any.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub worktree: Option<PathBuf>,
+}
+
 /// Structured failure used everywhere we don't want to leak a string-only error.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct ErrorInfo {

crates/maestro-protocol/src/routes.rs

@@ -21,10 +21,12 @@ pub const RECENT_DIRS: &str = "/api/recent-dirs";
 pub const PROJECTS: &str = "/api/projects";
 /// `GET` the enclosing repository of a path. Takes a `path` query param.
 pub const GITROOT: &str = "/api/gitroot";
+/// `GET` one repository's local branches. Takes a `path` query param.
+pub const BRANCHES: &str = "/api/branches";
 /// `WS` catalog snapshot + session deltas.
 pub const EVENTS: &str = "/api/events";
 
-/// Name of the query parameter [`DIRS`] and [`GITROOT`] both take.
+/// Name of the query parameter [`DIRS`], [`GITROOT`], and [`BRANCHES`] take.
 pub const PATH_QUERY: &str = "path";
 
 /// `DELETE /api/sessions/:id`.
@@ -174,7 +176,16 @@ mod tests {
 
     #[test]
     fn every_route_sits_under_the_api_prefix() {
-        for path in [SESSIONS, INFO, DIRS, RECENT_DIRS, PROJECTS, GITROOT, EVENTS] {
+        for path in [
+            SESSIONS,
+            INFO,
+            DIRS,
+            RECENT_DIRS,
+            PROJECTS,
+            GITROOT,
+            BRANCHES,
+            EVENTS,
+        ] {
             assert!(path.starts_with(API_PREFIX), "{path} escapes {API_PREFIX}");
         }
         assert!(attach(id()).starts_with(API_PREFIX));