add entire status benchmark

Author: evisdren

cmd/entire/cli/bench_test.go

@@ -0,0 +1,56 @@
+package cli
+
+import (
+	"io"
+	"testing"
+
+	"github.com/entireio/cli/cmd/entire/cli/benchutil"
+	"github.com/entireio/cli/cmd/entire/cli/paths"
+)
+
+// BenchmarkStatusCommand benchmarks the `entire status` command end-to-end.
+// This is the top-level entry point for understanding status command latency.
+//
+// Key I/O operations measured:
+//   - git rev-parse --show-toplevel (RepoRoot, cached after first call)
+//   - git rev-parse --git-common-dir (NewStateStore, per invocation)
+//   - git rev-parse --abbrev-ref HEAD (resolveWorktreeBranch, per unique worktree)
+//   - os.ReadFile for settings.json, each session state file
+//   - JSON unmarshaling for settings and each session state
+//
+// The primary scaling dimension is active session count.
+func BenchmarkStatusCommand(b *testing.B) {
+	b.Run("Short/NoSessions", benchStatus(0, false))
+	b.Run("Short/1Session", benchStatus(1, false))
+	b.Run("Short/5Sessions", benchStatus(5, false))
+	b.Run("Short/10Sessions", benchStatus(10, false))
+	b.Run("Short/20Sessions", benchStatus(20, false))
+	b.Run("Detailed/NoSessions", benchStatus(0, true))
+	b.Run("Detailed/5Sessions", benchStatus(5, true))
+}
+
+func benchStatus(sessionCount int, detailed bool) func(*testing.B) {
+	return func(b *testing.B) {
+		repo := benchutil.NewBenchRepo(b, benchutil.RepoOpts{})
+
+		// Create active session state files in .git/entire-sessions/
+		for range sessionCount {
+			repo.CreateSessionState(b, benchutil.SessionOpts{})
+		}
+
+		// runStatus uses paths.RepoRoot() which requires cwd to be in the repo.
+		b.Chdir(repo.Dir)
+		paths.ClearRepoRootCache()
+
+		b.ResetTimer()
+		for range b.N {
+			// Clear cache each iteration to simulate a fresh CLI invocation.
+			// In real usage, each `entire status` call starts cold.
+			paths.ClearRepoRootCache()
+
+			if err := runStatus(io.Discard, detailed); err != nil {
+				b.Fatalf("runStatus: %v", err)
+			}
+		}
+	}
+}