Add Pull Requests tab with auto-refresh and checkout

src-tauri/src/git/checkout.rs

@@ -0,0 +1,71 @@
+use super::cli::{run, GitError};
+use super::github::fetch_pr;
+use std::path::Path;
+
+/// Check if the working directory has uncommitted changes.
+///
+/// Returns true if there are any staged or unstaged changes that would be lost
+/// by switching branches.
+pub fn has_uncommitted_changes(repo: &Path) -> Result<bool, GitError> {
+    let output = run(repo, &["status", "--porcelain"])?;
+    // If status output is non-empty, there are changes
+    Ok(!output.trim().is_empty())
+}
+
+/// Checkout a PR branch, creating a local tracking branch like "pr-123".
+///
+/// This function:
+/// 1. Checks for uncommitted changes (returns error if dirty)
+/// 2. Fetches the PR using GitHub's PR refs
+/// 3. Creates or updates a local branch named "pr-{number}"
+/// 4. Checks out that branch
+///
+/// Returns the name of the created/updated branch (e.g., "pr-123").
+///
+/// # Errors
+///
+/// - Returns error if there are uncommitted changes
+/// - Returns error if PR fetch fails
+/// - Returns error if branch creation/checkout fails
+pub fn checkout_pr_branch(
+    repo: &Path,
+    pr_number: u64,
+    base_ref: &str,
+) -> Result<String, GitError> {
+    // 1. Check for uncommitted changes
+    if has_uncommitted_changes(repo)? {
+        return Err(GitError::CommandFailed(
+            "Cannot checkout PR: you have uncommitted changes. Commit or stash them first."
+                .into(),
+        ));
+    }
+
+    // 2. Fetch PR (reuses existing fetch_pr logic)
+    let _diff_spec = fetch_pr(repo, base_ref, pr_number)?;
+
+    // 3. Create local tracking branch "pr-{number}"
+    let branch_name = format!("pr-{}", pr_number);
+    let pr_ref = format!("refs/pull/{}/head", pr_number);
+
+    // Check if branch exists
+    let branch_exists = run(repo, &["rev-parse", "--verify", &format!("refs/heads/{}", branch_name)]).is_ok();
+
+    if branch_exists {
+        // Update existing branch to point to PR head
+        run(repo, &["branch", "-f", &branch_name, &pr_ref])?;
+    } else {
+        // Create new branch
+        run(repo, &["branch", &branch_name, &pr_ref])?;
+    }
+
+    // 4. Checkout the branch
+    run(repo, &["checkout", &branch_name])?;
+
+    log::info!(
+        "Checked out PR #{} to branch '{}'",
+        pr_number,
+        branch_name
+    );
+
+    Ok(branch_name)
+}

src-tauri/src/git/mod.rs

@@ -1,10 +1,12 @@
+mod checkout;
 mod cli;
 mod commit;
 mod diff;
 pub mod github;
 mod refs;
 mod types;
 
+pub use checkout::{checkout_pr_branch, has_uncommitted_changes};
 pub use cli::GitError;
 pub use commit::commit;
 pub use diff::{get_file_diff, list_diff_files};

src-tauri/src/lib.rs

@@ -182,6 +182,30 @@ async fn sync_review_to_github(
         .map_err(|e| e.to_string())
 }
 
+/// Check if the working directory has uncommitted changes.
+///
+/// Returns true if there are any staged or unstaged changes that would be lost
+/// by switching branches.
+#[tauri::command(rename_all = "camelCase")]
+fn has_uncommitted_changes(repo_path: Option<String>) -> Result<bool, String> {
+    let path = get_repo_path(repo_path.as_deref());
+    git::has_uncommitted_changes(path).map_err(|e| e.to_string())
+}
+
+/// Checkout a PR branch, creating a local tracking branch like "pr-123".
+///
+/// Returns error if there are uncommitted changes.
+/// Returns the name of the created/updated branch (e.g., "pr-123").
+#[tauri::command(rename_all = "camelCase")]
+fn checkout_pr_branch(
+    repo_path: Option<String>,
+    pr_number: u64,
+    base_ref: String,
+) -> Result<String, String> {
+    let path = get_repo_path(repo_path.as_deref());
+    git::checkout_pr_branch(path, pr_number, &base_ref).map_err(|e| e.to_string())
+}
+
 // =============================================================================
 // Review Commands
 // =============================================================================
@@ -369,6 +393,8 @@ pub fn run() {
             fetch_pr,
             sync_review_to_github,
             invalidate_pr_cache,
+            has_uncommitted_changes,
+            checkout_pr_branch,
             // Review commands
             get_review,
             add_comment,