battle-viewer e2e: mock user.games.battle ConnectRPC command

Phase 28 moved the battle fetch off the REST passthrough onto the
signed envelope, so the Playwright spec's `page.route(...)` against
the old REST path no longer intercepts anything and the viewer
times out waiting for data. Update the spec to:

- Build a FlatBuffers `BattleReport` payload in
  `fixtures/battle-fbs.ts` (mirrors `report-fbs.ts`'s pattern).
- Add a `user.games.battle` case to the ExecuteCommand mock that
  decodes the FBS `GameBattleRequest`, returns the encoded report
  when the battle_id matches the seeded one, and surfaces a
  canonical `not_found` resultCode otherwise.
- Drop the obsolete REST route stubs.
- Drive the negative-path test with a real UUID that does not match
  the seeded one, so the gateway-side switch is the source of the
  404 (the old `missing-uuid` literal was no longer a valid wire
  shape for the UUID decoder).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

ui/frontend/tests/e2e/battle-viewer.spec.ts

@@ -1,9 +1,9 @@
 // Phase 27 — Playwright coverage for the Battle Viewer.
 //
-// Mocks both the Connect-RPC `user.games.report` (so the report
+// Mocks the Connect-RPC `user.games.report` (report with battles +
-// renders battles + bombings) and the REST forwarder
+// bombings) and `user.games.battle` (Phase 28 migration; the viewer
-// `/api/v1/user/games/{game_id}/battles/{turn}/{battle_id}` (so the
+// fetches the full BattleReport through the signed envelope instead
-// viewer page loads its `BattleReport` without an engine).
+// of the old REST passthrough).
 // Drives three flows:
 //   1. Reports view → click battle UUID → viewer renders.
 //   2. Playback controls: play / step back.
@@ -18,6 +18,7 @@ import { expect, test, type Page } from "@playwright/test";
 import { ExecuteCommandRequestSchema } from "../../src/proto/galaxy/gateway/v1/edge_gateway_pb";
 import { UUID } from "../../src/proto/galaxy/fbs/common";
 import { GameReportRequest } from "../../src/proto/galaxy/fbs/report";
+import { GameBattleRequest } from "../../src/proto/galaxy/fbs/battle";
 
 import {
 	buildOrderResponsePayload,
@@ -25,6 +26,10 @@ import {
 } from "./fixtures/order-fbs";
 import { buildMyGamesListPayload, type GameFixture } from "./fixtures/lobby-fbs";
 import { buildReportPayload } from "./fixtures/report-fbs";
+import {
+	buildBattlePayload,
+	type BattleFixture,
+} from "./fixtures/battle-fbs";
 import { forgeExecuteCommandResponseJson } from "./fixtures/sign-response";
 
 const GAME_ID = "00000000-0000-0000-0000-000000000010";
@@ -33,13 +38,14 @@ const SESSION_ID = "device-session-battle";
 const RACE_A = "aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa";
 const RACE_B = "bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb";
 
-const SAMPLE_BATTLE = {
+const SAMPLE_BATTLE: BattleFixture = {
 	id: BATTLE_ID,
 	planet: 1,
 	planetName: "Earth",
 	races: { "0": RACE_A, "1": RACE_B },
-	ships: {
+	ships: [
-		"10": {
+		{
+			key: 10,
 			race: "Earthlings",
 			className: "Cruiser",
 			tech: { WEAPONS: 1 },
@@ -49,7 +55,8 @@ const SAMPLE_BATTLE = {
 			loadQuantity: 0,
 			inBattle: true,
 		},
-		"20": {
+		{
+			key: 20,
 			race: "Bajori",
 			className: "Hawk",
 			tech: { SHIELDS: 1 },
@@ -59,7 +66,7 @@ const SAMPLE_BATTLE = {
 			loadQuantity: 0,
 			inBattle: true,
 		},
-	},
+	],
 	protocol: [
 		{ a: 0, sa: 10, d: 1, sd: 20, x: false },
 		{ a: 0, sa: 10, d: 1, sd: 20, x: true },
@@ -160,6 +167,23 @@ async function mockGatewayAndBattle(page: Page): Promise<void> {
 				case "user.games.order.get":
 					payload = buildOrderGetResponsePayload(GAME_ID, [], Date.now(), false);
 					break;
+				case "user.games.battle": {
+					const fb = GameBattleRequest.getRootAsGameBattleRequest(
+						new ByteBuffer(req.payloadBytes),
+					);
+					const id = fb.battleId();
+					if (
+						id !== null &&
+						id.hi() === BigInt("0x1111111111111111") &&
+						id.lo() === BigInt("0x1111111111111111")
+					) {
+						payload = buildBattlePayload(SAMPLE_BATTLE);
+					} else {
+						resultCode = "not_found";
+						payload = new Uint8Array();
+					}
+					break;
+				}
 				default:
 					resultCode = "internal_error";
 					payload = new Uint8Array();
@@ -179,23 +203,6 @@ async function mockGatewayAndBattle(page: Page): Promise<void> {
 		},
 	);
 
-	await page.route(
-		`**/api/v1/user/games/${GAME_ID}/battles/1/${BATTLE_ID}`,
-		async (route) => {
-			await route.fulfill({
-				status: 200,
-				contentType: "application/json",
-				body: JSON.stringify(SAMPLE_BATTLE),
-			});
-		},
-	);
-
-	await page.route(
-		`**/api/v1/user/games/${GAME_ID}/battles/1/missing-uuid`,
-		async (route) => {
-			await route.fulfill({ status: 404 });
-		},
-	);
 }
 
 async function bootSession(page: Page): Promise<void> {
@@ -267,7 +274,9 @@ test.describe("Phase 27 battle viewer", () => {
 
 		await mockGatewayAndBattle(page);
 		await bootSession(page);
-		await page.goto(`/games/${GAME_ID}/battle/missing-uuid?turn=1`);
+		await page.goto(
+			`/games/${GAME_ID}/battle/22222222-2222-2222-2222-222222222222?turn=1`,
+		);
 
 		await expect(page.getByTestId("battle-not-found")).toBeVisible();
 	});

ui/frontend/tests/e2e/fixtures/battle-fbs.ts

@@ -0,0 +1,128 @@
+// Phase 28 — FBS BattleReport payload builder used by Battle Viewer
+// Playwright specs. Mirrors the `user.games.battle` ConnectRPC
+// response that the gateway re-encodes from the engine's JSON.
+
+import { Builder } from "flatbuffers";
+
+import {
+	BattleActionReport,
+	BattleReport,
+	BattleReportGroup,
+	RaceEntry,
+	ShipEntry,
+	TechEntry,
+	UUID,
+} from "../../../src/proto/galaxy/fbs/battle";
+
+export interface BattleGroupFixture {
+	key: number;
+	race: string;
+	className: string;
+	tech?: Record<string, number>;
+	num: number;
+	numLeft: number;
+	loadType?: string;
+	loadQuantity?: number;
+	inBattle?: boolean;
+}
+
+export interface BattleActionFixture {
+	a: number;
+	sa: number;
+	d: number;
+	sd: number;
+	x: boolean;
+}
+
+export interface BattleFixture {
+	id: string;
+	planet: number;
+	planetName: string;
+	races: Record<string, string>;
+	ships: BattleGroupFixture[];
+	protocol: BattleActionFixture[];
+}
+
+export function buildBattlePayload(fixture: BattleFixture): Uint8Array {
+	const builder = new Builder(512);
+
+	const planetNameOff = builder.createString(fixture.planetName);
+
+	const raceOffsets: number[] = [];
+	for (const [keyStr, value] of Object.entries(fixture.races)) {
+		const key = Number(keyStr);
+		const [hi, lo] = uuidToHiLo(value);
+		RaceEntry.startRaceEntry(builder);
+		RaceEntry.addKey(builder, BigInt(key));
+		RaceEntry.addValue(builder, UUID.createUUID(builder, hi, lo));
+		raceOffsets.push(RaceEntry.endRaceEntry(builder));
+	}
+	const racesVec = BattleReport.createRacesVector(builder, raceOffsets);
+
+	const shipOffsets: number[] = [];
+	for (const ship of fixture.ships) {
+		const techOffsets: number[] = [];
+		for (const [tk, tv] of Object.entries(ship.tech ?? {})) {
+			const tkOff = builder.createString(tk);
+			TechEntry.startTechEntry(builder);
+			TechEntry.addKey(builder, tkOff);
+			TechEntry.addValue(builder, tv);
+			techOffsets.push(TechEntry.endTechEntry(builder));
+		}
+		const techVec = BattleReportGroup.createTechVector(builder, techOffsets);
+		const raceStrOff = builder.createString(ship.race);
+		const classNameOff = builder.createString(ship.className);
+		const loadTypeOff = builder.createString(ship.loadType ?? "");
+		BattleReportGroup.startBattleReportGroup(builder);
+		BattleReportGroup.addInBattle(builder, ship.inBattle ?? true);
+		BattleReportGroup.addNumber(builder, BigInt(ship.num));
+		BattleReportGroup.addNumberLeft(builder, BigInt(ship.numLeft));
+		BattleReportGroup.addLoadQuantity(builder, ship.loadQuantity ?? 0);
+		BattleReportGroup.addTech(builder, techVec);
+		BattleReportGroup.addRace(builder, raceStrOff);
+		BattleReportGroup.addClassName(builder, classNameOff);
+		BattleReportGroup.addLoadType(builder, loadTypeOff);
+		const groupOff = BattleReportGroup.endBattleReportGroup(builder);
+		ShipEntry.startShipEntry(builder);
+		ShipEntry.addKey(builder, BigInt(ship.key));
+		ShipEntry.addValue(builder, groupOff);
+		shipOffsets.push(ShipEntry.endShipEntry(builder));
+	}
+	const shipsVec = BattleReport.createShipsVector(builder, shipOffsets);
+
+	const protocolOffsets: number[] = [];
+	for (const action of fixture.protocol) {
+		BattleActionReport.startBattleActionReport(builder);
+		BattleActionReport.addAttacker(builder, BigInt(action.a));
+		BattleActionReport.addAttackerShipClass(builder, BigInt(action.sa));
+		BattleActionReport.addDefender(builder, BigInt(action.d));
+		BattleActionReport.addDefenderShipClass(builder, BigInt(action.sd));
+		BattleActionReport.addDestroyed(builder, action.x);
+		protocolOffsets.push(BattleActionReport.endBattleActionReport(builder));
+	}
+	const protocolVec = BattleReport.createProtocolVector(
+		builder,
+		protocolOffsets,
+	);
+
+	const [idHi, idLo] = uuidToHiLo(fixture.id);
+	BattleReport.startBattleReport(builder);
+	BattleReport.addId(builder, UUID.createUUID(builder, idHi, idLo));
+	BattleReport.addPlanet(builder, BigInt(fixture.planet));
+	BattleReport.addPlanetName(builder, planetNameOff);
+	BattleReport.addRaces(builder, racesVec);
+	BattleReport.addShips(builder, shipsVec);
+	BattleReport.addProtocol(builder, protocolVec);
+	builder.finish(BattleReport.endBattleReport(builder));
+	return builder.asUint8Array();
+}
+
+function uuidToHiLo(value: string): [bigint, bigint] {
+	const hex = value.replace(/-/g, "").toLowerCase();
+	if (hex.length !== 32 || /[^0-9a-f]/.test(hex)) {
+		throw new Error(`buildBattlePayload: invalid uuid ${value}`);
+	}
+	const hi = BigInt(`0x${hex.slice(0, 16)}`);
+	const lo = BigInt(`0x${hex.slice(16, 32)}`);
+	return [hi, lo];
+}