chrisp/brackt
1
1
Fork 0
Code Issues 42 Pull requests Projects Releases Packages Wiki Activity Actions 2

Fix OOM in CI: make WorldCupSimulator simulation count configurable for tests

Browse source 
Tests now pass numSimulations=500 instead of the production default of 50,000.
Six simulator tests × 50k iterations each was exhausting the 4GB heap on GitHub
Actions runners. Also reduce simGroupMatch stat tests from 50k to 5k iterations.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
This commit is contained in:
Chris Parsons 2026-03-29 10:23:23 -07:00
parent 54d1c92b09
commit f85f81673f
2 changed files with 23 additions and 17 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

30
app/services/simulations/__tests__/world-cup-simulator.test.ts
View file

@ -17,31 +17,31 @@ describe("simGroupMatch", () => {
it("equal teams draw ≈28% of the time", () => {
let draws = 0;
const N = 50_000;
const N = 5_000;
for (let i = 0; i < N; i++) {
if (simGroupMatch(1500, 1500) === "draw") draws++;
}
const drawRate = draws / N;
// BASE_DRAW_RATE = 0.28 at eloDiff=0; accept ±3% from sampling noise
expect(drawRate).toBeGreaterThan(0.25);
expect(drawRate).toBeLessThan(0.31);
// BASE_DRAW_RATE = 0.28 at eloDiff=0; accept ±5% from sampling noise at N=5k
expect(drawRate).toBeGreaterThan(0.23);
expect(drawRate).toBeLessThan(0.33);
});
it("draw rate decays with large Elo gap", () => {
let draws = 0;
const N = 50_000;
const N = 5_000;
for (let i = 0; i < N; i++) {
if (simGroupMatch(2000, 1400) === "draw") draws++;
}
const drawRate = draws / N;
// eloDiff = 600 → pDraw ≈ 0.28 * exp(-1.2) ≈ 0.084; accept ±3%
expect(drawRate).toBeLessThan(0.13);
// eloDiff = 600 → pDraw ≈ 0.28 * exp(-1.2) ≈ 0.084; accept ±5%
expect(drawRate).toBeLessThan(0.15);
});
it("strong favorite wins more often than underdog", () => {
let wins = 0;
let losses = 0;
const N = 50_000;
const N = 5_000;
for (let i = 0; i < N; i++) {
const r = simGroupMatch(1900, 1600);
if (r === "win") wins++;
@ -110,7 +110,7 @@ describe("WorldCupSimulator", () => {
mockDb.query.tournamentGroups.findMany.mockResolvedValue([]);
mockDb.query.playoffMatches.findMany.mockResolvedValue([]);
const sim = new WorldCupSimulator();
const sim = new WorldCupSimulator(500);
await expect(sim.simulate("season-1")).rejects.toThrow("No participants found");
});
@ -121,7 +121,7 @@ describe("WorldCupSimulator", () => {
mockDb.query.tournamentGroups.findMany.mockResolvedValue([]);
mockDb.query.playoffMatches.findMany.mockResolvedValue([]);
const sim = new WorldCupSimulator();
const sim = new WorldCupSimulator(500);
const results = await sim.simulate("season-1");
expect(results).toHaveLength(48);
const ids = new Set(results.map((r) => r.participantId));
@ -137,7 +137,7 @@ describe("WorldCupSimulator", () => {
mockDb.query.tournamentGroups.findMany.mockResolvedValue([]);
mockDb.query.playoffMatches.findMany.mockResolvedValue([]);
const sim = new WorldCupSimulator();
const sim = new WorldCupSimulator(500);
const results = await sim.simulate("season-1");
const sumFirst = results.reduce((s, r) => s + r.probabilities.probFirst, 0);
@ -158,7 +158,7 @@ describe("WorldCupSimulator", () => {
mockDb.query.tournamentGroups.findMany.mockResolvedValue([]);
mockDb.query.playoffMatches.findMany.mockResolvedValue([]);
const sim = new WorldCupSimulator();
const sim = new WorldCupSimulator(500);
const results = await sim.simulate("season-1");
for (const r of results) {
@ -179,7 +179,7 @@ describe("WorldCupSimulator", () => {
mockDb.query.tournamentGroups.findMany.mockResolvedValue([]);
mockDb.query.playoffMatches.findMany.mockResolvedValue([]);
const sim = new WorldCupSimulator();
const sim = new WorldCupSimulator(500);
const results = await sim.simulate("season-1");
// probFirst + probSecond + probThird + probFourth should cover all probability mass
@ -235,7 +235,7 @@ describe("WorldCupSimulator", () => {
mockDb.query.tournamentGroups.findMany.mockResolvedValue([group, ...remainingGroups]);
mockDb.query.playoffMatches.findMany.mockResolvedValue([]);
const sim = new WorldCupSimulator();
const sim = new WorldCupSimulator(500);
const results = await sim.simulate("season-1");
const p3Result = results.find((r) => r.participantId === "p3");
@ -255,7 +255,7 @@ describe("WorldCupSimulator", () => {
mockDb.query.tournamentGroups.findMany.mockResolvedValue([]);
mockDb.query.playoffMatches.findMany.mockResolvedValue([]);
const sim = new WorldCupSimulator();
const sim = new WorldCupSimulator(500);
const results = await sim.simulate("season-1");
for (const r of results) {

10
app/services/simulations/world-cup-simulator.ts
View file

@ -303,6 +303,12 @@ function normalizeProbabilities(
// ─── Main simulator ───────────────────────────────────────────────────────────
export class WorldCupSimulator implements Simulator {
private readonly numSimulations: number;
constructor(numSimulations = NUM_SIMULATIONS) {
this.numSimulations = numSimulations;
}
async simulate(sportsSeasonId: string): Promise<SimulationResult[]> {
const db = database();
@ -465,7 +471,7 @@ export class WorldCupSimulator implements Simulator {
counts.qfLoser.set(id, 0);
}
for (let sim = 0; sim < NUM_SIMULATIONS; sim++) {
for (let sim = 0; sim < this.numSimulations; sim++) {
// ── Group stage ──────────────────────────────────────────────
const advancingFromGroup: string[] = []; // group winners + runners-up (24 teams)
const thirdPlaceTeams: TeamStats[] = []; // 12 third-place teams
@ -570,7 +576,7 @@ export class WorldCupSimulator implements Simulator {
}
// 8. Convert counts to probabilities
const N = NUM_SIMULATIONS;
const N = this.numSimulations;
const numQfLosers = 4; // 4 QF losers per sim
const results: SimulationResult[] = participantIds.map((id) => {