Enable Biome rules 3

app/components/CustomThemeSelector.tsx

@@ -3,10 +3,7 @@ import * as React from "react";
 import { useTranslation } from "react-i18next";
 import * as v from "valibot";
 import type { CustomTheme } from "~/db/tables-json";
-import {
-	CUSTOM_THEME_VARS,
-	type CustomThemeVar,
-} from "~/features/theme/theme-constants";
+import { CUSTOM_THEME_VARS } from "~/features/theme/theme-constants";
 import { useCopyToClipboard } from "~/hooks/useCopyToClipboard";
 import {
 	ACCENT_CHROMA_MULTIPLIERS,
@@ -308,9 +305,9 @@ export function CustomThemeSelector({
 
 	const handleReset = () => {
 		setThemeInput(DEFAULT_THEME_INPUT);
-		CUSTOM_THEME_VARS.forEach((varDef: CustomThemeVar) => {
+		for (const varDef of CUSTOM_THEME_VARS) {
 			document.documentElement.style.removeProperty(varDef);
-		});
+		}
 		onReset();
 	};
 

app/components/ObjectiveTimeline.tsx

@@ -252,7 +252,7 @@ export function ObjectiveTimeline({
 
 /** One tick every 25 up to the top of the data, none below zero so the control gutter stays clean. */
 function countAxisTicks(max: number) {
-	const ticks = [];
+	const ticks: Array<{ value: number }> = [];
 	for (let value = 0; value <= max; value += COUNT_TICK_STEP) {
 		ticks.push({ value });
 	}

app/db/json-columns.test.ts

@@ -4,7 +4,9 @@ import { JSON_COLUMNS } from "./json-columns";
 
 describe("JSON_COLUMNS", () => {
 	test("matches the JSONColumnType declarations in tables.ts", () => {
-		expect([...JSON_COLUMNS].sort()).toEqual(jsonColumnsFromTablesSource());
+		expect([...JSON_COLUMNS].sort(alphabetically)).toEqual(
+			jsonColumnsFromTablesSource(),
+		);
 	});
 });
 
@@ -17,7 +19,7 @@ function jsonColumnsFromTablesSource() {
 		const [, interfaceName, body] = match;
 		if (interfaceName === "DB") continue;
 
-		const columns = [];
+		const columns: string[] = [];
 		for (const line of body.split("\n")) {
 			const columnMatch = line.match(
 				/^\s*(\w+)\??:\s*.*JSONColumnType(?:Nullable)?</,
@@ -30,7 +32,7 @@ function jsonColumnsFromTablesSource() {
 	}
 
 	const dbInterfaceBody = source.slice(source.indexOf("export interface DB {"));
-	const entries = [];
+	const entries: string[] = [];
 	for (const match of dbInterfaceBody.matchAll(/^\t(\w+): (\w+);/gm)) {
 		const [, tableName, interfaceName] = match;
 		for (const column of jsonColumnsByInterface.get(interfaceName) ?? []) {
@@ -38,5 +40,7 @@ function jsonColumnsFromTablesSource() {
 		}
 	}
 
-	return entries.sort();
+	return entries.sort(alphabetically);
 }
+
+const alphabetically = (a: string, b: string) => a.localeCompare(b);

app/db/seed/dev/tournaments.ts

@@ -467,7 +467,7 @@ async function registerTeams({
 	registeredAt?: Date;
 	mapPool?: () => MapPool;
 }) {
-	const teams = [];
+	const teams: Awaited<ReturnType<typeof TournamentTeamFactory.create>>[] = [];
 	for (const [i, roster] of rosters.entries()) {
 		teams.push(
 			await TournamentTeamFactory.create(

app/features/build-analyzer/components/PerInkTankGrid.tsx

@@ -191,21 +191,9 @@ function calculateGrid({
 	subsUsed: number;
 }) {
 	const result: ("N/A" | ShotCellData)[][] = [];
-	for (
-		let issAPIndex = 0;
-		issAPIndex < AP_VALUES_TO_SHOW.length;
-		issAPIndex++
-	) {
-		const issAP = AP_VALUES_TO_SHOW[issAPIndex];
-
+	for (const issAP of AP_VALUES_TO_SHOW) {
 		const row: ("N/A" | ShotCellData)[] = [];
-		for (
-			let ismAPIndex = 0;
-			ismAPIndex < AP_VALUES_TO_SHOW.length;
-			ismAPIndex++
-		) {
-			const ismAP = AP_VALUES_TO_SHOW[ismAPIndex];
-
+		for (const ismAP of AP_VALUES_TO_SHOW) {
 			if (!apsArePossible(issAP, ismAP)) {
 				row.push("N/A" as const);
 				continue;

app/features/build-analyzer/routes/analyzer.tsx

@@ -1196,7 +1196,10 @@ function subDefenseGraphOptions({
 			.map((d) => damageToKey(d)),
 	);
 
-	const result = [];
+	const result: Array<{
+		label: string;
+		data: Array<{ primary: number; secondary: number }>;
+	}> = [];
 
 	for (const key of distanceKeys) {
 		const distance = key.split(",")[0];

app/features/calendar/components/FiltersBar.tsx

@@ -45,7 +45,7 @@ export function FiltersBar() {
 	};
 
 	const modesFormatted = () => {
-		const parts = [];
+		const parts: string[] = [];
 		if (filters.modes.length < modesShortWithSpecial.length) {
 			parts.push(filters.modes.join(", "));
 		}
@@ -57,7 +57,7 @@ export function FiltersBar() {
 	};
 
 	const eventTypeFormatted = () => {
-		const parts = [];
+		const parts: string[] = [];
 		if (filters.games.length < gamesShort.length) {
 			parts.push(filters.games.join(", "));
 		}
@@ -89,7 +89,7 @@ export function FiltersBar() {
 	};
 
 	const tagsFormatted = () => {
-		const parts = [];
+		const parts: string[] = [];
 		if (filters.tagsIncluded.length > 0) {
 			parts.push(`+${filters.tagsIncluded.length}`);
 		}
@@ -101,7 +101,7 @@ export function FiltersBar() {
 	};
 
 	const organizersFormatted = () => {
-		const parts = [];
+		const parts: string[] = [];
 		if (filters.orgsIncluded.length > 0) {
 			parts.push(`+${filters.orgsIncluded.length}`);
 		}
@@ -115,7 +115,7 @@ export function FiltersBar() {
 	};
 
 	const timeAndSizeFormatted = () => {
-		const parts = [];
+		const parts: string[] = [];
 		if (filters.preferredStartTime !== "ANY") {
 			parts.push(
 				t(

app/features/changelog/core/entries.server.ts

@@ -73,6 +73,7 @@ function parseEntryFile(fileName: string): ChangelogGraphicEntry {
 			`Invalid frontmatter in changelog entry "${fileName}": ${
 				error instanceof v.ValiError ? error.message : String(error)
 			}`,
+			{ cause: error },
 		);
 	}
 

app/features/chat/ChatRoomResolver.server.test.ts

@@ -112,7 +112,9 @@ describe("ChatRoomResolver.resolve", () => {
 		const room = await resolveOrThrow(await groupChatRoomId(group.id));
 
 		expect(room.type).toBe("SQ_GROUP");
-		expect(room.participantUserIds.sort()).toEqual(memberUserIds.sort());
+		expect(room.participantUserIds.sort(byId)).toEqual(
+			memberUserIds.sort(byId),
+		);
 		expect(room.url).toBe("/q/looking");
 		// a group chat resolves no observers of its own, site staff aside
 		expect(hasPermission(room, "OBSERVE", { id: outsiderId() })).toBe(false);
@@ -136,8 +138,8 @@ describe("ChatRoomResolver.resolve", () => {
 		const room = await resolveOrThrow(match.chatRoomId!);
 
 		expect(room.type).toBe("SQ_MATCH");
-		expect(room.participantUserIds.sort()).toEqual(
-			[...alphaUserIds, ...bravoUserIds].sort(),
+		expect(room.participantUserIds.sort(byId)).toEqual(
+			[...alphaUserIds, ...bravoUserIds].sort(byId),
 		);
 		expect(room.titleParams).toEqual({ matchId: String(match.id) });
 		expect(room.url).toContain(String(match.id));
@@ -155,8 +157,8 @@ describe("ChatRoomResolver.resolve", () => {
 		const room = await resolveOrThrow(chatRoomId);
 
 		expect(room.type).toBe("TOURNAMENT_MATCH");
-		expect(room.participantUserIds.sort()).toEqual(
-			[...teamAlphaUserIds, ...teamBravoUserIds].sort(),
+		expect(room.participantUserIds.sort(byId)).toEqual(
+			[...teamAlphaUserIds, ...teamBravoUserIds].sort(byId),
 		);
 		expect(room.titleParams.matchId).toBe(String(matchId));
 		expect(room.titleParams.tournamentName).toEqual(expect.any(String));
@@ -187,7 +189,9 @@ describe("ChatRoomResolver.resolve", () => {
 		const room = await resolveOrThrow(await teamChatRoomId(team.id));
 
 		expect(room.type).toBe("TOURNAMENT_TEAM");
-		expect(room.participantUserIds.sort()).toEqual(memberUserIds.sort());
+		expect(room.participantUserIds.sort(byId)).toEqual(
+			memberUserIds.sort(byId),
+		);
 		expect(room.titleParams.teamName).toEqual(expect.any(String));
 		expect(room.permissions.OBSERVE).toContain(authorId);
 	});
@@ -199,8 +203,8 @@ describe("ChatRoomResolver.resolve", () => {
 		const room = await resolveOrThrow(chatRoomId);
 
 		expect(room.type).toBe("SCRIM");
-		expect(room.participantUserIds.sort()).toEqual(
-			[...postUserIds, ...requestUserIds].sort(),
+		expect(room.participantUserIds.sort(byId)).toEqual(
+			[...postUserIds, ...requestUserIds].sort(byId),
 		);
 		expect(room.titleParams.startsAt).toBe(
 			String(dateToDatabaseTimestamp(startsAt)),
@@ -223,11 +227,18 @@ describe("ChatRoomResolver.findAllByUserId", () => {
 
 		const rooms = await ChatRoomResolver.findAllByUserId(alphaUserIds[0]);
 
-		expect(rooms.map((room) => [room.roomId, room.type]).sort()).toEqual(
+		expect(
+			rooms
+				.map((room) => ({ roomId: room.roomId, type: room.type }))
+				.sort(byRoomId),
+		).toEqual(
 			[
-				[match.chatRoomId!, "SQ_MATCH"],
-				[await groupChatRoomId(match.alphaGroup.id), "SQ_GROUP"],
-			].sort(),
+				{ roomId: match.chatRoomId!, type: "SQ_MATCH" },
+				{
+					roomId: await groupChatRoomId(match.alphaGroup.id),
+					type: "SQ_GROUP",
+				},
+			].sort(byRoomId),
 		);
 	});
 
@@ -501,3 +512,8 @@ const teamChatRoomId = async (teamId: number) => {
 
 	return team.chatRoomId!;
 };
+
+const byId = (a: number, b: number) => a - b;
+
+const byRoomId = (a: { roomId: number }, b: { roomId: number }) =>
+	a.roomId - b.roomId;

app/features/comp-analyzer/components/RangeVisualization.tsx

@@ -165,13 +165,13 @@ function TrajectoryChart({
 
 	const groundY = yScale(0);
 
-	const xTicks = [];
+	const xTicks: number[] = [];
 	const xStep = Math.ceil(maxRange / 5);
 	for (let x = 0; x <= maxRange; x += xStep) {
 		xTicks.push(x);
 	}
 
-	const yTicks = [];
+	const yTicks: number[] = [];
 	const yStep = Math.ceil((maxY - minY) / 4);
 	for (let y = Math.ceil(minY); y <= maxY; y += yStep) {
 		yTicks.push(y);

app/features/comp-analyzer/core/damage-combinations.ts

@@ -443,9 +443,7 @@ function isExcessiveCombo(combo: DamageCombo): boolean {
 	);
 	const totalDamage = combo.totalDamage;
 
-	for (let i = 0; i < flatDamages.length; i++) {
-		const damage = flatDamages[i];
-
+	for (const damage of flatDamages) {
 		const reducedDamage = totalDamage - damage;
 		if (reducedDamage >= LETHAL_DAMAGE) {
 			return true;

app/features/img-export/components/ImageExportDialog.tsx

@@ -117,11 +117,13 @@ function ImageExportDialogContent({
 
 		let cancelled = false;
 
-		import("@zumer/snapdom").then(({ preCache }) => {
-			if (cancelled || !frameRef.current) return;
+		import("@zumer/snapdom")
+			.then(({ preCache }) => {
+				if (cancelled || !frameRef.current) return;
 
-			preCache(frameRef.current).catch(() => {});
-		});
+				return preCache(frameRef.current);
+			})
+			.catch(() => {});
 
 		return () => {
 			cancelled = true;

app/features/map-list-generator/core/map-pool-serializer/serializer.ts

@@ -7,7 +7,7 @@ import type { MapPoolObject, ReadonlyMapPoolObject } from "./types";
 export function mapPoolToSerializedString(
 	mapPool: ReadonlyMapPoolObject,
 ): string {
-	const serializedModes = [];
+	const serializedModes: string[] = [];
 
 	for (const mode of modesShort) {
 		const stages = mapPool[mode];

app/features/map-list-generator/core/map-pool.ts

@@ -42,11 +42,12 @@ export class MapPool {
 			return this.asSerialized;
 		}
 
-		// biome-ignore lint/suspicious/noAssignInExpressions: biome migration
-		return (this.asSerialized =
+		this.asSerialized =
 			typeof this.source === "string"
 				? this.source
-				: mapPoolToSerializedString(this.source));
+				: mapPoolToSerializedString(this.source);
+
+		return this.asSerialized;
 	}
 
 	get parsed(): ReadonlyMapPoolObject {
@@ -54,11 +55,12 @@ export class MapPool {
 			return this.asObject;
 		}
 
-		// biome-ignore lint/suspicious/noAssignInExpressions: biome migration
-		return (this.asObject =
+		this.asObject =
 			typeof this.source === "string"
 				? serializedStringToMapPool(this.source)
-				: this.source);
+				: this.source;
+
+		return this.asObject;
 	}
 
 	get dbList(): DbMapPoolList {

app/features/notifications/core/notify.server.test.ts

@@ -257,7 +257,9 @@ describe("notify()", () => {
 		expect(user10Notifications).toHaveLength(2);
 		expect(user11Notifications).toHaveLength(2);
 
-		const types = user10Notifications.map((n) => n.type).sort();
+		const types = user10Notifications
+			.map((n) => n.type)
+			.sort((a, b) => a.localeCompare(b));
 		expect(types).toEqual(["SCRIM_CANCELED", "SCRIM_SCHEDULED"]);
 	});
 

app/features/scanner/node/resources.ts

@@ -25,7 +25,10 @@ async function loadAtlasLazy(name: string): Promise<() => GlyphSet | null> {
 	const meta = JSON.parse(readFileSync(json, "utf8")) as AtlasMeta;
 	const image = await readImage(png);
 	let set: GlyphSet | null = null;
-	return () => (set ??= loadGlyphSet(image, meta));
+	return () => {
+		set ??= loadGlyphSet(image, meta);
+		return set;
+	};
 }
 
 /** Planner stage signatures; the (CPU) tile slicing runs on first access. */
@@ -36,7 +39,10 @@ async function loadPlannerStagesLazy(): Promise<() => PlannerStage[] | null> {
 	const manifest = JSON.parse(readFileSync(json, "utf8")) as PlannerManifest;
 	const atlas = await readImage(png);
 	let stages: PlannerStage[] | null = null;
-	return () => (stages ??= loadPlannerStages(atlas, manifest));
+	return () => {
+		stages ??= loadPlannerStages(atlas, manifest);
+		return stages;
+	};
 }
 
 /** Requires loadOpenCV() to have resolved. */

app/features/scanner/scanner-schemas.ts

@@ -129,6 +129,7 @@ type MutuallyAssignable<A, B> = [A] extends [B]
 
 // `true satisfies …` fails to compile the moment a schema and its core
 // interface disagree in either direction.
+// biome-ignore-start lint/suspicious/noUnusedExpressions: type-level assertions, no runtime effect
 true satisfies MutuallyAssignable<
 	v.InferOutput<typeof scannerMatchPlayerSchema>,
 	ScannerMatchPlayer
@@ -149,3 +150,4 @@ true satisfies MutuallyAssignable<
 	v.InferOutput<typeof scannerMatchSchema>,
 	ScannerMatch
 >;
+// biome-ignore-end lint/suspicious/noUnusedExpressions: type-level assertions, no runtime effect

app/features/scanner/tests/objective.test.ts

@@ -17,7 +17,7 @@ import { createScoreboardDetector } from "../core/detectors/scoreboard/index";
 import { createScoreboardBattleLogReplayDetector } from "../core/detectors/scoreboard-battle-log-replay/index";
 import { createScoreboardOwnDetector } from "../core/detectors/scoreboard-own/index";
 import type { DetectedEvent, Detector } from "../core/detectors/types";
-import { hueDistance, hueOf } from "../core/ink-color";
+import { hueDistance, hueOf, type InkRgb } from "../core/ink-color";
 import {
 	type Fixture,
 	isFieldSkipped,
@@ -143,7 +143,7 @@ test("cast fixture pair: team ink hues identify sides across camera swaps", asyn
 	].map((name) => fixtures.find((fixture) => fixture.name === name));
 	assert.ok(pair[0] && pair[1], "cast fixture pair missing");
 
-	const colors = [];
+	const colors: Array<readonly [InkRgb, InkRgb]> = [];
 	for (const fixture of pair) {
 		const { events } = await runDetectorOnFixture(detector, fixture!);
 		const teamColor = (

app/features/scanner/worker/analyzer.worker.ts

@@ -115,8 +115,10 @@ async function analyzeFrame(
 	// ship back the exact analyzed pixels (lossless, capture resolution) so the
 	// UI never re-grabs a later frame — encoded at most once per frame
 	let encoded: Promise<Blob> | null = null;
-	const frameBlob = () =>
-		(encoded ??= canvas.convertToBlob({ type: "image/png" }));
+	const frameBlob = () => {
+		encoded ??= canvas.convertToBlob({ type: "image/png" });
+		return encoded;
+	};
 
 	try {
 		for (const detector of detectors) {

app/features/sendouq/SQGroupRepository.server.ts

@@ -792,7 +792,7 @@ export function insertLike({
 				.execute();
 		} catch (error) {
 			if (errorIsSqliteForeignKeyConstraintFailure(error)) {
-				throw new SendouQError(error.message);
+				throw new SendouQError(error.message, { cause: error });
 			}
 			throw error;
 		}
@@ -829,7 +829,7 @@ export function insertSuggestion({
 				.execute();
 		} catch (error) {
 			if (errorIsSqliteForeignKeyConstraintFailure(error)) {
-				throw new SendouQError(error.message);
+				throw new SendouQError(error.message, { cause: error });
 			}
 			throw error;
 		}

app/features/sendouq/q-utils.server.ts

@@ -3,8 +3,8 @@ import * as SkillRepository from "~/features/mmr/SkillRepository.server";
 import type { TieredSkill } from "~/features/mmr/tiered.server";
 
 export class SendouQError extends Error {
-	constructor(message: string) {
-		super(message);
+	constructor(message: string, options?: ErrorOptions) {
+		super(message, options);
 		this.name = "SendouQError";
 	}
 }

app/features/tournament-bracket/core/Deadline.ts

@@ -1,6 +1,13 @@
 const PREP_TIME_MINUTES = 6.5;
 const MINUTES_PER_GAME = 6.5;
 
+type GameMarker = {
+	gameNumber: number;
+	percentage: number;
+	gameStartMinute: number;
+	maxMinute: number;
+};
+
 /** Acceptable max duration of a match in minutes (preparation time + game time). */
 export function totalMatchTime(maxGamesCount: number): number {
 	return PREP_TIME_MINUTES + MINUTES_PER_GAME * maxGamesCount;
@@ -15,14 +22,9 @@ export function progressPercentage(
 }
 
 /** Position of each game on the match timeline as a percentage. */
-export function gameMarkers(maxGamesCount: number): Array<{
-	gameNumber: number;
-	percentage: number;
-	gameStartMinute: number;
-	maxMinute: number;
-}> {
+export function gameMarkers(maxGamesCount: number): GameMarker[] {
 	const totalMinutes = totalMatchTime(maxGamesCount);
-	const markers = [];
+	const markers: GameMarker[] = [];
 
 	for (let i = 1; i <= maxGamesCount; i++) {
 		const gameStartMinute = PREP_TIME_MINUTES + MINUTES_PER_GAME * (i - 1);

app/features/tournament-bracket/core/Progression.ts

@@ -207,10 +207,10 @@ export function validatedBrackets(
 	try {
 		parsed = toOutputBracketFormat(brackets);
 	} catch (e) {
-		if ((e as { badBracketIdx: number }).badBracketIdx) {
+		if (e instanceof BadBracketError) {
 			return {
 				type: "PLACEMENTS_PARSE_ERROR",
-				bracketIdx: (e as { badBracketIdx: number }).badBracketIdx,
+				bracketIdx: e.bracketIdx,
 			};
 		}
 
@@ -372,6 +372,15 @@ export function bracketsToValidationError(
 	return null;
 }
 
+class BadBracketError extends Error {
+	readonly bracketIdx: number;
+
+	constructor(bracketIdx: number) {
+		super(`Bracket at index ${bracketIdx} has invalid placements`);
+		this.bracketIdx = bracketIdx;
+	}
+}
+
 function toOutputBracketFormat(brackets: InputBracket[]): ParsedBracket[] {
 	const result = brackets.map((bracket, bracketIdx) => {
 		return {
@@ -395,10 +404,10 @@ function toOutputBracketFormat(brackets: InputBracket[]): ParsedBracket[] {
 						sourceBracket?.type === "swiss" &&
 						sourceBracket?.settings?.advanceThreshold;
 					if (!isSwissWithEarlyAdvance) {
-						throw { badBracketIdx: bracketIdx };
+						throw new BadBracketError(bracketIdx);
 					}
 				} else if (parsed === null) {
-					throw { badBracketIdx: bracketIdx };
+					throw new BadBracketError(bracketIdx);
 				}
 
 				return {

app/features/tournament-bracket/core/engine/swiss/pairing.ts

@@ -185,7 +185,7 @@ export function pairUp(players: SwissPairingTeam[]) {
 	const scoreSums = [
 		...new Set(
 			scoreGroups.flatMap((s, i, a) => {
-				const sums = [];
+				const sums: number[] = [];
 				for (let j = i; j < a.length; j++) {
 					sums.push(s + a[j]);
 				}
@@ -243,8 +243,7 @@ function generateWeightedPairs({
 	for (let i = 0; i < playerArray.length; i++) {
 		const curr = playerArray[i];
 		const next = playerArray.slice(i + 1);
-		for (let j = 0; j < next.length; j++) {
-			const opp = next[j];
+		for (const opp of next) {
 			let wt =
 				75 - 75 / (scoreGroups.indexOf(Math.min(curr.score, opp.score)) + 2);
 			wt +=

app/features/tournament-bracket/core/tests/test-utils.ts

@@ -29,7 +29,7 @@ export const tournamentCtxTeam = (
 };
 
 const nTeams = (n: number, startingId: number) => {
-	const teams = [];
+	const teams: TournamentData["ctx"]["teams"] = [];
 	for (let i = 0; i < n; i++) {
 		teams.push(tournamentCtxTeam(i + 1, tournamentCtxTeam(i + startingId)));
 	}

app/features/tournament-lfg/TournamentLFGRepository.server.test.ts

@@ -246,8 +246,8 @@ describe("startLooking", () => {
 
 		const roomsChangedUserIds = await startLooking(team.id);
 
-		expect(roomsChangedUserIds.sort()).toEqual(
-			[users.id(1), users.id(2)].sort(),
+		expect(roomsChangedUserIds.sort(byId)).toEqual(
+			[users.id(1), users.id(2)].sort(byId),
 		);
 
 		const chatRoomId = await chatRoomIdOf(team.id);
@@ -390,8 +390,8 @@ describe("mergeTeams", () => {
 			maxGroupSize: 4,
 		});
 
-		expect(roomsChangedUserIds.sort()).toEqual(
-			[users.id(1), users.id(2)].sort(),
+		expect(roomsChangedUserIds.sort(byId)).toEqual(
+			[users.id(1), users.id(2)].sort(byId),
 		);
 	});
 
@@ -664,3 +664,5 @@ describe("findAllSubsByTournamentId", () => {
 		expect(subs).toHaveLength(0);
 	});
 });
+
+const byId = (a: number, b: number) => a - b;

app/features/tournament/TournamentTeamRepository.server.test.ts

@@ -336,8 +336,8 @@ describe("TournamentTeamRepository", () => {
 				TournamentTeamRepository.deleteById(team.id),
 			);
 
-			expect(roomsChangedUserIds.sort()).toEqual(
-				[ownerId(), memberId()].sort(),
+			expect(roomsChangedUserIds.sort(byId)).toEqual(
+				[ownerId(), memberId()].sort(byId),
 			);
 		});
 
@@ -393,3 +393,5 @@ describe("TournamentTeamRepository", () => {
 		});
 	});
 });
+
+const byId = (a: number, b: number) => a - b;

app/features/user-page/UserRepository.test.ts

@@ -323,7 +323,9 @@ describe("UserRepository", () => {
 					{},
 				);
 
-				const teams = [];
+				const teams: Awaited<
+					ReturnType<typeof TournamentTeamFactory.create>
+				>[] = [];
 				for (const user of [topUser, topMate, lowUser, lowMate]) {
 					teams.push(
 						await TournamentTeamFactory.create(
@@ -586,7 +588,9 @@ describe("UserRepository", () => {
 			const tomorrow = await UserRepository.findAllPatronsForFooter();
 
 			expect(ids(today)).not.toEqual(ids(tomorrow));
-			expect(ids(today).sort()).toEqual(ids(tomorrow).sort());
+			expect(ids(today).sort((a, b) => a - b)).toEqual(
+				ids(tomorrow).sort((a, b) => a - b),
+			);
 		});
 	});
 });

app/features/user-page/components/ResultsFiltersBar.tsx

@@ -383,7 +383,7 @@ function YearSelect({
 const selectableYears = () => {
 	const currentYear = new Date().getFullYear();
 
-	const result = [];
+	const result: number[] = [];
 	for (let year = currentYear; year >= RESULTS_FIRST_YEAR; year--) {
 		result.push(year);
 	}

app/features/user-page/core/widgets/portfolio-loaders.server.ts

@@ -8,6 +8,7 @@ import * as LFGRepository from "~/features/lfg/LFGRepository.server";
 import * as LiveStreamRepository from "~/features/live-streams/LiveStreamRepository.server";
 import { BANNED_MAPS } from "~/features/match-profile/banned-maps";
 import * as MatchProfileRepository from "~/features/match-profile/MatchProfileRepository.server";
+import type { TierName } from "~/features/mmr/mmr-constants";
 import { ordinalToSp } from "~/features/mmr/mmr-utils";
 import { userSkills as _userSkills } from "~/features/mmr/tiered.server";
 import * as TeamRepository from "~/features/team/TeamRepository.server";
@@ -54,7 +55,12 @@ export const WIDGET_LOADERS = {
 			return null;
 		}
 
-		let peakData = null;
+		let peakData: {
+			peakSp: number;
+			tierName: TierName;
+			isPlus: boolean;
+			season: number;
+		} | null = null;
 		let maxOrdinal = Number.NEGATIVE_INFINITY;
 
 		for (const season of seasonsParticipatedIn) {

app/modules/tournament-map-list-generator/balanced-map-list.ts

@@ -330,7 +330,7 @@ function generateWithInput(
 
 	function isNotFollowingModeOrder(stage: StageValidatorInput) {
 		let currentIndex = 0;
-		for (let i = 0; i < mapList.length; i++) {
+		for (const _ of mapList) {
 			currentIndex++;
 			if (currentIndex === input.modesIncluded.length) currentIndex = 0;
 		}

app/routines/notifySeasonEnd.test.ts

@@ -56,7 +56,9 @@ describe("NotifySeasonEndRoutine", () => {
 				},
 			}),
 		);
-		expect(notifiedUserIds().sort()).toEqual([users.id(1), users.id(2)].sort());
+		expect(notifiedUserIds().sort((a, b) => a - b)).toEqual(
+			[users.id(1), users.id(2)].sort((a, b) => a - b),
+		);
 	});
 
 	test("does NOT notify a participant whose skill is approximate", async () => {

app/utils/Test.ts

@@ -95,7 +95,12 @@ export function wrappedAction<T extends AnySchema>({
 				if (thrown instanceof Response) {
 					if (thrown.status === 302) return thrown;
 
-					throw new Error(`Response thrown with status code: ${thrown.status}`);
+					throw new Error(
+						`Response thrown with status code: ${thrown.status}`,
+						{
+							cause: thrown,
+						},
+					);
 				}
 
 				throw thrown;
@@ -145,7 +150,12 @@ export function wrappedLoader<T>({
 				return data as T;
 			} catch (thrown) {
 				if (thrown instanceof Response) {
-					throw new Error(`Response thrown with status code: ${thrown.status}`);
+					throw new Error(
+						`Response thrown with status code: ${thrown.status}`,
+						{
+							cause: thrown,
+						},
+					);
 				}
 
 				throw thrown;

app/utils/dates.ts

@@ -168,7 +168,7 @@ export function nullPaddedDatesOfMonth({ month, year }: MonthYear) {
 }
 
 function datesOfMonth({ month, year }: MonthYear) {
-	const dates = [];
+	const dates: Date[] = [];
 	const date = new Date(Date.UTC(year, month, 1));
 	while (date.getUTCMonth() === month) {
 		dates.push(new Date(date));

app/utils/random.ts

@@ -3,9 +3,8 @@ function cyrb128(str: string) {
 	let h2 = 3144134277;
 	let h3 = 1013904242;
 	let h4 = 2773480762;
-	// biome-ignore lint/suspicious/noImplicitAnyLet: biome migration
-	for (let i = 0, k; i < str.length; i++) {
-		k = str.charCodeAt(i);
+	for (let i = 0; i < str.length; i++) {
+		const k = str.charCodeAt(i);
 		h1 = h2 ^ Math.imul(h1 ^ k, 597399067);
 		h2 = h3 ^ Math.imul(h2 ^ k, 2869860233);
 		h3 = h4 ^ Math.imul(h3 ^ k, 951274213);

biome.json

@@ -34,7 +34,12 @@
 					"level": "error"
 				},
 				"noSkippedTests": "error",
-				"noParametersOnlyUsedInRecursion": "error"
+				"noParametersOnlyUsedInRecursion": "error",
+				"useArraySortCompare": "error",
+				"noEvolvingTypes": "error",
+				"noReturnAssign": "error",
+				"noNestedPromises": "error",
+				"noUnusedExpressions": "error"
 			},
 			"correctness": {
 				"noUndeclaredVariables": "error",
@@ -113,6 +118,10 @@
 				"noSubstr": "error",
 				"useUnifiedTypeSignatures": "error",
 				"useReadonlyClassProperties": "error",
+				"useForOf": "error",
+				"useErrorCause": "error",
+				"useThrowOnlyError": "error",
+				"noNamespace": "error",
 				"useFilenamingConvention": {
 					"level": "error",
 					"options": {
@@ -145,7 +154,8 @@
 					"fix": "safe",
 					"level": "error"
 				},
-				"noUselessCatchBinding": "error"
+				"noUselessCatchBinding": "error",
+				"noForEach": "error"
 			},
 			"performance": {
 				"noSyncScripts": "error"
@@ -182,6 +192,16 @@
 				}
 			}
 		},
+		{
+			"includes": ["types/**/*.d.ts"],
+			"linter": {
+				"rules": {
+					"style": {
+						"noNamespace": "off"
+					}
+				}
+			}
+		},
 		{
 			"includes": ["app/**", "!app/modules/search-params/**"],
 			"plugins": ["./biome-plugins/no-raw-search-params.grit"]

e2e/api-public.spec.ts

@@ -417,7 +417,9 @@ async function organizedTournament(
 		startTimes: [dateToDatabaseTimestamp(addHours(new Date(), 2))],
 	});
 
-	const teams = [];
+	const teams: Awaited<
+		ReturnType<typeof factories.TournamentTeamFactory.create>
+	>[] = [];
 	for (let teamNth = 0; teamNth < teamCount; teamNth++) {
 		const roster = await factories.UserFactory.createMany(ROSTER_SIZE);
 		teams.push(

e2e/helpers/tournament.ts

@@ -172,7 +172,9 @@ export async function createTeams(
 	tournamentId: number,
 	seeds: TeamSeed[],
 ) {
-	const teams = [];
+	const teams: Awaited<
+		ReturnType<typeof factories.TournamentTeamFactory.create>
+	>[] = [];
 	for (const [i, seed] of seeds.entries()) {
 		const presetMembers = seed.members ?? [];
 		const rosterSize = seed.rosterSize ?? ROSTER_SIZE;

e2e/leaderboards.spec.ts

@@ -102,7 +102,8 @@ async function seedLeaderboards(factories: Factories) {
 	const alphaUserIds = [ADMIN_ID, ...mates.map((mate) => mate.id)];
 	const bravoUserIds = enemies.map((enemy) => enemy.id);
 
-	const matches = [];
+	const matches: Awaited<ReturnType<typeof factories.SQMatchFactory.create>>[] =
+		[];
 	for (let i = 0; i < MATCHES_COUNT_NEEDED_FOR_LEADERBOARD; i++) {
 		matches.push(
 			await factories.SQMatchFactory.create(

e2e/pages/builds/user-builds-page.ts

@@ -55,7 +55,7 @@ export class UserBuildsPage {
 		await this.locators.changeSortingButton.click();
 
 		const dialog = this.page.getByRole("dialog");
-		for (let i = 0; i < DEFAULT_BUILD_SORT.length; i++) {
+		for (const _ of DEFAULT_BUILD_SORT) {
 			await dialog.getByTestId("delete-sorting-button").click();
 		}
 		await dialog.getByRole("combobox").selectOption(sort);

e2e/tournament.spec.ts

@@ -349,7 +349,9 @@ test.describe("Tournament", () => {
 		});
 
 		const captains = await factories.UserFactory.createMany(SEEDED_TEAM_COUNT);
-		const teams = [];
+		const teams: Awaited<
+			ReturnType<typeof factories.TournamentTeamFactory.create>
+		>[] = [];
 		for (const [i, captain] of captains.entries()) {
 			teams.push(
 				await factories.TournamentTeamFactory.create({

migrations/20260815145515-leagues-as-normal-tournaments.ts

@@ -73,6 +73,16 @@ const SEASONS: Season[] = [
 	},
 ];
 
+type MigratedDivision = Season["divisions"][number] & {
+	tier: number | null;
+	castTwitchAccounts: string[] | null;
+	castedMatchesInfo: CastedMatchesInfo | null;
+	groupStageIdx: number;
+	playoffsIdx: number;
+	groupStageBracket: any;
+	playoffsBracket: any;
+};
+
 async function migrateSeason(trx: Transaction<any>, season: Season) {
 	const signup = await trx
 		.selectFrom("Tournament")
@@ -83,7 +93,7 @@ async function migrateSeason(trx: Transaction<any>, season: Season) {
 	// databases without the production league data (dev, tests)
 	if (!signup) return;
 
-	const divisions = [];
+	const divisions: MigratedDivision[] = [];
 	for (const [idx, division] of season.divisions.entries()) {
 		const row = await trx
 			.selectFrom("Tournament")

public/sw-2.js

@@ -59,8 +59,7 @@ self.addEventListener("notificationclick", (event) => {
 	event.waitUntil(
 		clients.matchAll({ type: "window" }).then((windowClients) => {
 			// Check if there is already a window/tab open with the target URL
-			for (let i = 0; i < windowClients.length; i++) {
-				const client = windowClients[i];
+			for (const client of windowClients) {
 				// If so, just focus it.
 				if (client.url === targetUrl && "focus" in client) {
 					return client.focus();

scripts/add-leaderboard-teams-to-tournament.ts

@@ -22,8 +22,10 @@ invariant(
 async function loadTournament() {
 	try {
 		return await tournamentFromDB(tournamentId);
-	} catch {
-		throw new Error(`Tournament with id ${tournamentId} not found`);
+	} catch (error) {
+		throw new Error(`Tournament with id ${tournamentId} not found`, {
+			cause: error,
+		});
 	}
 }
 

scripts/check-translation-jsons.ts

@@ -67,8 +67,8 @@ for (const file of fileNames) {
 			let otherLanguageContent: Record<string, string>;
 			try {
 				otherLanguageContent = JSON.parse(otherRawContent);
-			} catch {
-				throw new Error(`failed to parse ${lang}/${file}`);
+			} catch (error) {
+				throw new Error(`failed to parse ${lang}/${file}`, { cause: error });
 			}
 
 			const otherLanguageContentKeys = getKeysWithoutSuffix(
@@ -276,7 +276,7 @@ function MDOverviewTable({
 		(name) => name !== "weapons.json" && name !== "gear.json",
 	);
 
-	const rows = [];
+	const rows: string[] = [];
 
 	rows.push(
 		`| Language | Total | ${relevantFiles.map(MD.inlineCode).join(" | ")} |`,
@@ -285,7 +285,7 @@ function MDOverviewTable({
 	rows.push(`| :-- | :-: | ${relevantFiles.map(() => ":-:").join(" | ")} |`);
 
 	for (const [lang, missingKeysObj] of Object.entries(missingTranslations)) {
-		const cells = [];
+		const cells: string[] = [];
 
 		cells.push(MD.strong(lang));
 

scripts/download-prod-db.ts

@@ -123,6 +123,7 @@ async function main() {
 		fs.rmSync(stagedPath, { force: true });
 		throw new Error(
 			`Snapshot failed verification, no checkout was touched. The archive is kept at ${archivePath}\n${(error as Error).message}`,
+			{ cause: error },
 		);
 	}
 

scripts/scanner/scan-vod.ts

@@ -134,6 +134,7 @@ function parseArgs(argv: string[]): {
 	let duration: number | undefined;
 	let outPath: string | undefined;
 	let collectTelemetry = false;
+	// biome-ignore lint/style/useForOf: the index advances inside the loop to consume flag values
 	for (let i = 0; i < argv.length; i++) {
 		const arg = argv[i]!;
 		if (arg === "--fps") fps = Number(argv[++i]);