Fix "losses against" tiebreaker calculation with dropped teams Closes #1989

app/features/tournament-bracket/core/Bracket.test.ts

@@ -0,0 +1,40 @@
+import { describe, expect, it } from "vitest";
+import { Tournament } from "./Tournament";
+import { LOW_INK_DECEMBER_2024 } from "./tests/mocks-li";
+import invariant from "../../../utils/invariant";
+
+const TEAM_ERROR_404_ID = 17354;
+const TEAM_THIS_IS_FINE_ID = 17513;
+
+describe("swiss standings", () => {
+	it("should calculate losses against tied", () => {
+		const tournament = new Tournament({
+			...LOW_INK_DECEMBER_2024(),
+			simulateBrackets: false,
+		});
+
+		const standing = tournament
+			.bracketByIdx(0)
+			?.currentStandings(false)
+			.find((standing) => standing.team.id === TEAM_THIS_IS_FINE_ID);
+
+		invariant(standing, "Standing not found");
+
+		expect(standing.stats?.lossesAgainstTied).toBe(1);
+	});
+
+	it("should ignore early dropped out teams for standings (losses against tied)", () => {
+		const tournament = new Tournament({
+			...LOW_INK_DECEMBER_2024(),
+			simulateBrackets: false,
+		});
+
+		const standing = tournament
+			.bracketByIdx(0)
+			?.currentStandings(false)
+			.find((standing) => standing.team.id === TEAM_ERROR_404_ID);
+		invariant(standing, "Standing not found");
+
+		expect(standing.stats?.lossesAgainstTied).toBe(0); // they lost against "Tidy Tidings" but that team dropped out before final round
+	});
+});

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

@@ -1388,7 +1388,13 @@ class SwissBracket extends Bracket {
 			for (const team of teams) {
 				for (const team2 of teams) {
 					if (team.id === team2.id) continue;
-					if (team.setWins !== team2.setWins) continue;
+					if (
+						team.setWins !== team2.setWins ||
+						// check also set losses to account for dropped teams
+						team.setLosses !== team2.setLosses
+					) {
+						continue;
+					}
 
 					// they are different teams and are tied, let's check who won