fix(baseball): compute OBP/SLG/OPS in legacy aggregate recalc (#436)

src/app/baseball/actions/stats.ts

@@ -19,6 +19,7 @@ import {
   BaseballActionError,
 } from '@/lib/baseball/with-baseball-action';
 import { BaseballCapabilityError, requireBaseballCapability } from '@/lib/baseball/capabilities';
+import { computeCareerSlashLine } from '@/lib/baseball/aggregates/career-slash-line';
 
 /**
  * Shared error-message mapping for every action in this file. All exported
@@ -551,6 +552,10 @@ const recalculatePlayerAggregatesAction = withBaseballAction(
   const totalAtBats = stats.reduce((sum, s) => sum + (s.at_bats || 0), 0);
   const totalHits = stats.reduce((sum, s) => sum + (s.hits || 0), 0);
 
+  // Slash line — OBP/SLG/OPS from summed counting stats (null on zero
+  // denominators). Pure helper is unit-tested; see #436.
+  const { obp: careerObp, slg: careerSlg, ops: careerOps } = computeCareerSlashLine(stats);
+
   // Last 5 and 10 sessions
   const last5 = stats.slice(0, 5);
   const last10 = stats.slice(0, 10);
@@ -584,6 +589,9 @@ const recalculatePlayerAggregatesAction = withBaseballAction(
     team_id: teamId,
     total_sessions: stats.length,
     career_avg: careerAvg,
+    career_obp: careerObp,
+    career_slg: careerSlg,
+    career_ops: careerOps,
     practice_avg: practiceAvg,
     game_avg: gameAvg,
     pressure_gap: pressureGap,

src/lib/baseball/__tests__/career-slash-line.test.ts

@@ -0,0 +1,61 @@
+// =============================================================================
+// career-slash-line.test.ts
+//
+// Guards the career OBP/SLG/OPS derivation used by
+// `recalculatePlayerAggregates` (BaseballHelm #436). Pure function; no DB.
+// The headline case is a multi-session aggregate that exercises walks, sac
+// flies, and hit-by-pitch — the fields that pull OBP away from AVG.
+// =============================================================================
+
+import { describe, it, expect } from 'vitest';
+import {
+  computeCareerSlashLine,
+  type SlashLineStatRow,
+} from '@/lib/baseball/aggregates/career-slash-line';
+
+const row = (partial: Partial<SlashLineStatRow>): SlashLineStatRow => ({
+  at_bats: 0,
+  hits: 0,
+  doubles: 0,
+  triples: 0,
+  home_runs: 0,
+  walks: 0,
+  hit_by_pitch: 0,
+  sacrifice_flies: 0,
+  ...partial,
+});
+
+describe('computeCareerSlashLine', () => {
+  it('aggregates OBP/SLG/OPS across multiple sessions with walks, SF, and HBP', () => {
+    // Session 1: 4 AB, 2 H (1 double), 1 BB, 1 HBP
+    // Session 2: 6 AB, 2 H (1 HR), 1 BB, 1 SF
+    // Totals: AB 10, H 4, 2B 1, HR 1, BB 2, HBP 1, SF 1
+    const stats = [
+      row({ at_bats: 4, hits: 2, doubles: 1, walks: 1, hit_by_pitch: 1 }),
+      row({ at_bats: 6, hits: 2, home_runs: 1, walks: 1, sacrifice_flies: 1 }),
+    ];
+
+    const { obp, slg, ops } = computeCareerSlashLine(stats);
+
+    // OBP = (H + BB + HBP) / (AB + BB + HBP + SF) = (4 + 2 + 1) / (10 + 2 + 1 + 1) = 7/14 = .500
+    expect(obp).toBeCloseTo(0.5, 6);
+    // TB = H + 2B + 2·3B + 3·HR = 4 + 1 + 0 + 3 = 8; SLG = 8/10 = .800
+    expect(slg).toBeCloseTo(0.8, 6);
+    // OPS = .500 + .800 = 1.300
+    expect(ops).toBeCloseTo(1.3, 6);
+  });
+
+  it('returns null rates when every denominator is zero (no fabricated .000)', () => {
+    expect(computeCareerSlashLine([])).toEqual({ obp: null, slg: null, ops: null });
+    expect(computeCareerSlashLine([row({})])).toEqual({ obp: null, slg: null, ops: null });
+  });
+
+  it('yields a non-null OBP but null SLG/OPS when a player only walks (zero AB)', () => {
+    // A plate appearance that is all walks: OBP denominator is non-zero, AB is zero.
+    const { obp, slg, ops } = computeCareerSlashLine([row({ walks: 2, hit_by_pitch: 1 })]);
+    // OBP = (0 + 2 + 1) / (0 + 2 + 1 + 0) = 3/3 = 1.000
+    expect(obp).toBeCloseTo(1, 6);
+    expect(slg).toBeNull(); // zero AB → null, not 0
+    expect(ops).toBeNull(); // null when either component is null
+  });
+});

src/lib/baseball/aggregates/career-slash-line.ts

@@ -0,0 +1,61 @@
+// =============================================================================
+// career-slash-line.ts
+//
+// Pure derivation of a player's career OBP / SLG / OPS from summed counting
+// stats. Extracted from `recalculatePlayerAggregates` (src/app/baseball/
+// actions/stats.ts) so it can be unit-tested without a database.
+//
+// Honesty contract: every rate is null on a zero denominator — never a
+// fabricated .000. See BaseballHelm #436.
+// =============================================================================
+
+import type { BaseballPlayerStats } from '@/lib/types';
+
+/** The counting-stat fields the slash line is derived from. */
+export type SlashLineStatRow = Pick<
+  BaseballPlayerStats,
+  'at_bats' | 'hits' | 'doubles' | 'triples' | 'home_runs' | 'walks' | 'hit_by_pitch' | 'sacrifice_flies'
+>;
+
+export interface CareerSlashLine {
+  /** On-base percentage: (H + BB + HBP) / (AB + BB + HBP + SF); null on zero PA. */
+  obp: number | null;
+  /** Slugging: total bases / AB; null on zero AB. */
+  slg: number | null;
+  /** OPS = OBP + SLG; null when either component is null. */
+  ops: number | null;
+}
+
+/**
+ * Derive career OBP/SLG/OPS from a set of per-session counting stats.
+ * Sums across every row, then applies the standard formulas. Missing
+ * counting values are treated as 0; denominators of 0 yield null.
+ */
+export function computeCareerSlashLine(
+  stats: ReadonlyArray<SlashLineStatRow>,
+): CareerSlashLine {
+  const sum = (pick: (s: SlashLineStatRow) => number | null | undefined): number =>
+    stats.reduce((acc, s) => acc + (pick(s) || 0), 0);
+
+  const atBats = sum((s) => s.at_bats);
+  const hits = sum((s) => s.hits);
+  const doubles = sum((s) => s.doubles);
+  const triples = sum((s) => s.triples);
+  const homeRuns = sum((s) => s.home_runs);
+  const walks = sum((s) => s.walks);
+  const hitByPitch = sum((s) => s.hit_by_pitch);
+  const sacFlies = sum((s) => s.sacrifice_flies);
+
+  // OBP = (H + BB + HBP) / (AB + BB + HBP + SF)
+  const obpDenominator = atBats + walks + hitByPitch + sacFlies;
+  const obp = obpDenominator === 0 ? null : (hits + walks + hitByPitch) / obpDenominator;
+
+  // SLG = total bases / AB, where total bases = singles + 2·2B + 3·3B + 4·HR
+  //     = H + 2B + 2·3B + 3·HR
+  const totalBases = hits + doubles + 2 * triples + 3 * homeRuns;
+  const slg = atBats === 0 ? null : totalBases / atBats;
+
+  const ops = obp != null && slg != null ? obp + slg : null;
+
+  return { obp, slg, ops };
+}

supabase/migrations/20260701020000_baseball_player_aggregates_slash_line.sql

@@ -0,0 +1,20 @@
+-- BaseballHelm #436 — persist the slash line on player aggregates.
+--
+-- `recalculatePlayerAggregates` (src/app/baseball/actions/stats.ts) previously
+-- only wrote `career_avg`, but My Stats `StatsOverviewCards` reads
+-- `career_obp`, `career_slg`, and `career_ops`. Those columns never existed on
+-- the live `baseball_player_aggregates` table, so OBP/SLG/OPS permanently
+-- showed "---". Add them here (numeric, matching `career_avg`) so the recalc
+-- can compute and upsert the full slash line.
+--
+-- Idempotent: ADD COLUMN IF NOT EXISTS. No data backfill — the columns fill in
+-- on the next aggregate recalculation for each player.
+
+ALTER TABLE "public"."baseball_player_aggregates"
+    ADD COLUMN IF NOT EXISTS "career_obp" numeric;
+
+ALTER TABLE "public"."baseball_player_aggregates"
+    ADD COLUMN IF NOT EXISTS "career_slg" numeric;
+
+ALTER TABLE "public"."baseball_player_aggregates"
+    ADD COLUMN IF NOT EXISTS "career_ops" numeric;