Fix list command to skip empty JSON output and batch stale-review cleanup

Collapse redundant empty-session branch so --json falls through to the
normal serialization path instead of printing "[]" separately. Replace
per-branch load/save loop with a single state cycle to avoid racing
concurrent writes.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CLAUDE.md

@@ -120,7 +120,8 @@ Always use `.nothrow()` for commands that may fail non-fatally. Use `.quiet()` t
       "branch": "branch-name",
       "worktree": "/Users/you/.sandlot/repo/branch-name",
       "created_at": "2026-02-16T10:30:00Z",
-      "prompt": "optional initial prompt text"
+      "prompt": "optional initial prompt text",
+      "in_review": false
     }
   }
 }
@@ -149,7 +150,8 @@ Always use `.nothrow()` for commands that may fail non-fatally. Use `.quiet()` t
 - `sandlot squash` generates an AI commit message for the squash commit via `claudePipe()`; falls back to `"squash <branch>"`
 - `sandlot merge` and `sandlot squash` both delegate to `mergeAndClose()` in `helpers.ts`, which merges, resolves conflicts, commits, and then calls `closeAction()` to clean up
 - `sandlot list` discovers missing session prompts by parsing Claude's `history.jsonl` from inside the container
-- `sandlot list` shows four status icons: idle (dim `◌`), active (cyan `◯`), dirty/unsaved (yellow `◎`), saved (green `●`)
+- `sandlot list` shows five status icons: idle (dim `◯`), active (cyan `◎`), dirty/unsaved (yellow `◐`), saved (green `●`), review (magenta `⦿`)
+- `sandlot review` sets `in_review` on the session during the review and clears it in a `finally` block on exit; `list` detects stale `in_review` flags (Claude not active) and clears them from state
 - `sandlot new` and `sandlot open` auto-save changes when Claude exits (disable with `--no-save`)
 - `sandlot close` has a hidden `rm` alias
 - Default behavior (no subcommand): always runs `list` (which prints "No active sessions." if empty)

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@because/sandlot",
-  "version": "0.0.37",
+  "version": "0.0.38",
   "description": "Sandboxed, branch-based development with Claude",
   "type": "module",
   "bin": {

src/commands/list.ts

@@ -2,7 +2,7 @@ import { homedir } from "os"
 import * as git from "../git.ts"
 import * as vm from "../vm.ts"
 import * as state from "../state.ts"
-import { reset, dim, bold, green, yellow, cyan, white, red } from "../fmt.ts"
+import { reset, dim, green, yellow, cyan, magenta, red } from "../fmt.ts"
 
 export async function action(opts: { json?: boolean }) {
   const root = await git.repoRoot()
@@ -30,12 +30,7 @@ export async function action(opts: { json?: boolean }) {
     } catch {}
   }
 
-  if (opts.json) {
-    console.log(JSON.stringify(sessions, null, 2))
-    return
-  }
-
-  if (sessions.length === 0) {
+  if (sessions.length === 0 && !opts.json) {
     console.log("◆ No active sessions.")
     if ((await vm.status()) !== "running") {
       console.log(`\n${red}VM is not running.${reset}`)
@@ -44,9 +39,16 @@ export async function action(opts: { json?: boolean }) {
   }
 
   // Determine status for each session in parallel
+  const staleReviewBranches: string[] = []
   const statusEntries = await Promise.all(
     sessions.map(async (s): Promise<[string, string]> => {
-      if (await vm.isClaudeActive(s.worktree, s.branch)) return [s.branch, "active"]
+      const active = await vm.isClaudeActive(s.worktree, s.branch)
+      if (active && s.in_review) return [s.branch, "review"]
+      if (!active && s.in_review) {
+        staleReviewBranches.push(s.branch)
+        s.in_review = false
+      }
+      if (active) return [s.branch, "active"]
       const dirty = await git.isDirty(s.worktree)
       if (dirty) return [s.branch, "dirty"]
       const commits = await git.hasNewCommits(s.worktree)
@@ -55,14 +57,28 @@ export async function action(opts: { json?: boolean }) {
   )
   const statuses = Object.fromEntries(statusEntries)
 
+  // Clear stale in_review flags in a single load/save cycle
+  if (staleReviewBranches.length > 0) {
+    const fresh = await state.load(root)
+    for (const branch of staleReviewBranches) {
+      if (fresh.sessions[branch]) fresh.sessions[branch].in_review = false
+    }
+    await state.save(root, fresh).catch(() => {})
+  }
+
   if (opts.json) {
     const withStatus = sessions.map(s => ({ ...s, status: statuses[s.branch] }))
     console.log(JSON.stringify(withStatus, null, 2))
     return
   }
 
-  const icons: Record<string, string> = { idle: `${dim}◯${reset}`, active: `${cyan}◎${reset}`, dirty: `${yellow}◐${reset}`, saved: `${green}●${reset}` }
-  const branchColors: Record<string, string> = { idle: dim, active: cyan, dirty: yellow, saved: green }
+  const styleDefs: [string, string, string][] = [
+    ["idle", dim, "◯"], ["active", cyan, "◎"], ["dirty", yellow, "◐"],
+    ["saved", green, "●"], ["review", magenta, "⦿"],
+  ]
+  const styles = Object.fromEntries(
+    styleDefs.map(([k, c, ch]) => [k, { icon: `${c}${ch}${reset}`, color: c }])
+  )
   const branchWidth = Math.max(6, ...sessions.map((s) => s.branch.length))
   const cols = process.stdout.columns || 80
   const prefixWidth = branchWidth + 4
@@ -71,15 +87,14 @@ export async function action(opts: { json?: boolean }) {
 
   for (const s of sessions) {
     const prompt = (s.prompt ?? "").split("\n")[0]
-    const status = statuses[s.branch]
-    const icon = icons[status]
-    const bc = branchColors[status]
+    const status = statuses[s.branch] ?? "idle"
+    const { icon, color: bc } = styles[status]
     const maxPrompt = cols - prefixWidth
     const truncated = maxPrompt > 3 && prompt.length > maxPrompt ? prompt.slice(0, maxPrompt - 3) + "..." : prompt
     console.log(`${icon} ${bc}${s.branch.padEnd(branchWidth)}${reset}  ${dim}${truncated}${reset}`)
   }
 
-  console.log(`\n${dim}◯ idle${reset} · ${cyan}◎ active${reset} · ${yellow}◐ unsaved${reset} · ${green}● saved${reset}`)
+  console.log(`\n${dim}◯ idle${reset} · ${cyan}◎ active${reset} · ${yellow}◐ unsaved${reset} · ${green}● saved${reset} · ${magenta}⦿ review${reset}`)
 
   if ((await vm.status()) !== "running") {
     console.log(`\n${red}VM is not running.${reset}`)

src/commands/review.ts

@@ -1,9 +1,10 @@
 import * as vm from "../vm.ts"
+import * as state from "../state.ts"
 import { spinner } from "../spinner.ts"
 import { requireSession, saveChanges } from "./helpers.ts"
 
 export async function action(branch: string, extra: string | undefined, opts: { print?: boolean }) {
-  const { session } = await requireSession(branch)
+  const { root, session } = await requireSession(branch)
 
   const spin = spinner("Starting container", branch)
   await vm.ensure((msg) => { spin.text = msg })
@@ -67,15 +68,26 @@ Your thoughts, in brief.
 `
   if (extra) prompt += "\n\n" + extra
 
-  if (opts.print) {
-    spin.text = "Running review…"
-    const result = await vm.claude(session.worktree, { print: prompt })
-    spin.stop()
-    if (result.output) process.stdout.write(result.output + "\n")
-  } else {
-    spin.succeed("Session ready")
-    await vm.claude(session.worktree, { prompt })
-  }
+  session.in_review = true
+  await state.setSession(root, session)
 
-  await saveChanges(session.worktree, session.branch)
+  try {
+    if (opts.print) {
+      spin.text = "Running review…"
+      const result = await vm.claude(session.worktree, { print: prompt })
+      if (result.output) process.stdout.write(result.output + "\n")
+    } else {
+      spin.succeed("Session ready")
+      await vm.claude(session.worktree, { prompt })
+    }
+  } finally {
+    spin.stop()
+    // Load fresh session to avoid clobbering changes made during the review
+    const fresh = await state.getSession(root, session.branch)
+    if (fresh) {
+      fresh.in_review = false
+      await state.setSession(root, fresh).catch(() => {})
+    }
+    if (!opts.print) await saveChanges(session.worktree, session.branch).catch(() => {})
+  }
 }

src/fmt.ts

@@ -5,6 +5,7 @@ export const dim = "\x1b[2m"
 export const green = "\x1b[32m"
 export const yellow = "\x1b[33m"
 export const red = "\x1b[31m"
+export const magenta = "\x1b[35m"
 export const cyan = "\x1b[36m"
 
 // ── Formatted output ────────────────────────────────────────────────

src/state.ts

@@ -7,6 +7,7 @@ export interface Session {
   worktree: string
   created_at: string
   prompt?: string
+  in_review?: boolean
 }
 
 export interface State {