0.4.0 — fix queue-add race + per-item remove button (#10, #11)

server/db.test.ts

@@ -22,6 +22,7 @@ function makeState(id: string): GameState {
     },
     events: [],
     pending: [],
+    version: 1,
   };
 }
 
@@ -54,6 +55,11 @@ describe('openDb', () => {
     expect(db.load('a')?.events).toHaveLength(1);
     expect([...db.listIds()].sort()).toEqual(['a', 'b']); // still two rows
 
+    // the monotonic version is persisted with the state and round-trips
+    s.version = 3;
+    db.save(s);
+    expect(db.load('a')?.version).toBe(3);
+
     db.close();
   });
 

server/engine.test.ts

@@ -9,6 +9,7 @@ import {
   isMeaningful,
   parseTurnResult,
   queueRoundItem,
+  removeRoundItem,
   runTurn,
   validateTurnResult,
 } from './engine';
@@ -72,6 +73,7 @@ function baseState(): GameState {
     },
     events: [],
     pending: [],
+    version: 1,
   };
 }
 
@@ -206,8 +208,11 @@ describe('runTurn (batched round, deterministic stub)', () => {
     expect(state.events[0].nation).toBe('uk');
     expect(state.events[0].outcome).toBe('success');
     expect(result.stateChanges).toEqual([{ nation: 'uk', stat: 'military', op: 'set', value: 85 }]);
+    // committing a turn is a new revision too
+    expect(state.version).toBe(2);
     // the original object is not mutated (a fresh queue was consumed)
     expect(original.pending).toHaveLength(1);
+    expect(original.version).toBe(1);
   });
 
   it('an empty round: turn advances, one political "world moves on" event, pending stays empty', async () => {
@@ -286,6 +291,61 @@ describe('queueRoundItem', () => {
     expect(after.pending[0]).toEqual({ kind: 'diplomacy', to: 'us', text: 'hello' });
     // the original state is not mutated
     expect(before.pending).toHaveLength(0);
+    expect(before.version).toBe(1);
+  });
+
+  it('bumps the monotonic version on each queue mutation', () => {
+    const a = queueRoundItem(baseState(), { kind: 'action', text: 'one' });
+    expect(a.version).toBe(2);
+    const b = queueRoundItem(a, { kind: 'action', text: 'two' });
+    expect(b.version).toBe(3);
+    // and never backwards: two consecutive adds from the same base both
+    // advance past it, so a late snapshot of the older state is always older.
+    const b2 = queueRoundItem(baseState(), { kind: 'action', text: 'two' });
+    expect(b2.version).toBe(2);
+    expect(b.version).toBeGreaterThan(b2.version);
+  });
+
+  it('treats a legacy state without a version field as version 0', () => {
+    const legacy = { ...baseState() } as Omit<GameState, 'version'> & { version?: number };
+    delete legacy.version; // a row saved before the version field existed
+    // simulate a legacy row coming back from SQLite: the JSON has no field.
+    const after = queueRoundItem(legacy as unknown as GameState, {
+      kind: 'action',
+      text: 'first after upgrade',
+    });
+    expect(after.version).toBe(1);
+  });
+});
+
+describe('removeRoundItem', () => {
+  it('removes the item at the index, bumps the version, and leaves the input untouched', () => {
+    const state = baseState();
+    state.pending = [
+      { kind: 'action', text: 'one' },
+      { kind: 'diplomacy', to: 'us', text: 'two' },
+      { kind: 'action', text: 'three' },
+    ];
+    const next = removeRoundItem(state, 1);
+    expect(next).not.toBeNull();
+    expect(next!.version).toBe(2);
+    expect(next!.pending).toEqual([
+      { kind: 'action', text: 'one' },
+      { kind: 'action', text: 'three' },
+    ]);
+    expect(state.pending).toHaveLength(3); // original untouched
+    expect(state.version).toBe(1);
+  });
+
+  it('returns null for out-of-bounds or non-integer indices (route answers 400, nothing mutates)', () => {
+    const state = baseState();
+    state.pending = [{ kind: 'action', text: 'one' }];
+    expect(removeRoundItem(state, -1)).toBeNull();
+    expect(removeRoundItem(state, 1)).toBeNull(); // == length
+    expect(removeRoundItem(state, 5)).toBeNull();
+    expect(removeRoundItem(state, 0.5)).toBeNull();
+    expect(removeRoundItem(state, Number.NaN)).toBeNull();
+    expect(state.pending).toHaveLength(1); // still untouched
   });
 });
 
@@ -346,7 +406,7 @@ describe('applyTurnResult', () => {
     expect(JSON.stringify(state)).toBe(snapshot);
   });
 
-  it('clears the pending round on commit', () => {
+  it('clears the pending round on commit and bumps the version', () => {
     const state = baseState();
     state.pending = [{ kind: 'action', text: 'x' }];
     const result: TurnResult = {
@@ -358,7 +418,9 @@ describe('applyTurnResult', () => {
     };
     const next = applyTurnResult(state, result);
     expect(next.pending).toEqual([]);
+    expect(next.version).toBe(2);
     expect(state.pending).toHaveLength(1); // original untouched
+    expect(state.version).toBe(1);
   });
 });
 

server/engine.ts

@@ -284,6 +284,7 @@ function genericUnclearEvent(state: GameState): TurnEventSpec {
  */
 export function applyTurnResult(state: GameState, result: TurnResult): GameState {
   const next: GameState = JSON.parse(JSON.stringify(state));
+  next.version = (state.version ?? 0) + 1; // every mutation is a new revision
   const actingTurn = state.turn; // this action resolves the current turn
   next.turn = state.turn + 1; // then we advance to the next turn to play
   next.date = isDateLike(result.date) ? result.date : addDays(state.date, 2);
@@ -325,15 +326,34 @@ export function applyTurnResult(state: GameState, result: TurnResult): GameState
 /**
  * Immutably queue one item onto a round: append it to `pending` and return a new
  * state. This never advances the turn or the date — that only happens when a
- * round is committed via runTurn. Exported so the append-without-advance behavior
- * is unit-testable, and reused by the server's /action and /diplomacy routes.
+ * round is committed via runTurn. Bumps `version` (a new revision, so stale SSE
+ * snapshots can never clobber it client-side). Exported so the append-without-
+ * advance behavior is unit-testable, and reused by the /action and /diplomacy
+ * routes.
  */
 export function queueRoundItem(state: GameState, item: RoundItem): GameState {
   const next: GameState = JSON.parse(JSON.stringify(state));
+  next.version = (state.version ?? 0) + 1;
   next.pending.push(item);
   return next;
 }
 
+/**
+ * Immutably remove one item from the pending round by index and return a new
+ * state (bumping `version`). Returns `null` when the index is missing or not a
+ * valid, in-bounds integer position, so the route can answer 400 without
+ * mutating anything. Reused by the server's /queue/remove route.
+ */
+export function removeRoundItem(state: GameState, index: number | undefined): GameState | null {
+  if (index === undefined || !Number.isInteger(index) || index < 0 || index >= state.pending.length) {
+    return null;
+  }
+  const next: GameState = JSON.parse(JSON.stringify(state));
+  next.version = (state.version ?? 0) + 1;
+  next.pending.splice(index, 1);
+  return next;
+}
+
 /**
  * Run one turn end-to-end against the (injectable) LLM: build prompts, call the
  * model ONCE over the whole pending batch, parse/validate, retry once with a

server/index.ts

@@ -9,11 +9,16 @@ import path from 'node:path';
 import { fileURLToPath } from 'node:url';
 
 import { deepClone } from '../shared/protocol';
-import type { AddActionRequest, AddDiplomacyRequest, CreateGameRequest } from '../shared/protocol';
+import type {
+  AddActionRequest,
+  AddDiplomacyRequest,
+  CreateGameRequest,
+  RemoveQueueItemRequest,
+} from '../shared/protocol';
 import type { GameState } from '../shared/types';
 import { createLlmClient } from './llm';
 import { makeStubLlmClient } from './stub';
-import { askAdvisor, queueRoundItem, runTurn } from './engine';
+import { askAdvisor, queueRoundItem, removeRoundItem, runTurn } from './engine';
 import { buildRegionMap } from './map';
 import { createPresetStore } from './presets';
 import { openDb, type Db } from './db';
@@ -114,6 +119,7 @@ app.post('/api/games', (req: Request, res) => {
     nations: Object.fromEntries(preset.nations.map((n) => [n.id, deepClone(n)])),
     events: [],
     pending: [],
+    version: 1, // the first saved revision; every later mutation bumps it
   };
   db.save(state);
   res.json({ game: state });
@@ -179,6 +185,22 @@ app.post('/api/games/:id/diplomacy', (req, res) => {
   res.json({ game: next });
 });
 
+// Remove one item from the pending round, by its index in `game.pending`. No
+// LLM call, no turn advance — same fast save → broadcast → respond order as the
+// add routes above. The mutated state bumps `version`, so clients (which apply
+// states "never go backwards") always reconcile to it.
+app.post('/api/games/:id/queue/remove', (req, res) => {
+  const id = req.params.id;
+  const game = db.load(id);
+  if (!game) return res.status(404).json({ error: 'game not found' });
+  const index = (req.body as RemoveQueueItemRequest | undefined)?.index;
+  const next = removeRoundItem(game, index);
+  if (!next) return res.status(400).json({ error: 'invalid queue index' });
+  db.save(next);
+  broadcast(id, 'state', { state: next });
+  res.json({ game: next });
+});
+
 // Jump forward: commit the whole pending round (or an empty one) to the model
 // in a single turn. applyTurnResult clears the pending queue on the returned
 // state. 404 for not-found/preset-missing; 502 for LLM/model (transport) errors.

server/map.test.ts

@@ -30,6 +30,7 @@ const state: GameState = {
   },
   events: [],
   pending: [],
+  version: 1,
 };
 
 describe('buildRegionMap', () => {