RedditBot/tests/account-browsing-simulation.test.ts

import Database from 'better-sqlite3';
import { beforeEach, describe, expect, it, vi } from 'vitest';
import { runMigrations } from '../src/database/client.js';
import {
  AccountBrowsingSimulationRepository,
  type BrowsingDecisionRecord,
} from '../src/database/browsing-simulation-repository.js';
import type { BrowsingThing, RedditPost } from '../src/reddit/api.js';
import {
  AccountBrowsingSimulationService,
  dailyTarget,
  isQuietTime,
} from '../src/services/account-browsing-simulation.js';
import { createMockLogger } from './mockLogger.js';

const ACCOUNT = '@t2_owner:reddit.com';
const OTHER = '@t2_other:reddit.com';
const NOW = new Date(2026, 7, 11, 12, 0, 0, 0).getTime();

function insertAccount(db: Database.Database, accountId: string, username: string): void {
  db.prepare(`
    INSERT INTO reddit_accounts (
      account_id, reddit_username, matrix_user_id, status, is_active,
      cookies_json, matrix_credentials_json, created_at, updated_at
    ) VALUES (?, ?, ?, 'verified', 1, '[]', '{}', 0, 0)
  `).run(accountId, username, accountId);
}

function post(id: string, overrides: Partial<RedditPost> = {}): RedditPost {
  return {
    id,
    name: `t3_${id}`,
    subreddit: 'AskUK',
    author: `author_${id}`,
    title: `A useful discussion about topic ${id}`,
    selftext: 'Enough context for an ordinary browsing choice.',
    url: `https://www.reddit.com/r/AskUK/comments/${id}/`,
    permalink: `/r/AskUK/comments/${id}/topic/`,
    thumbnail: '',
    is_self: true,
    created_utc: NOW / 1_000 - 60,
    over_18: false,
    spoiler: false,
    ...overrides,
  };
}

function comment(id: string, parentPostId: string): BrowsingThing {
  return {
    fullname: `t1_${id}`,
    kind: 'comment',
    subreddit: 'AskUK',
    author: `commenter_${id}`,
    permalink: `/r/AskUK/comments/${parentPostId}/topic/${id}/`,
    createdAt: NOW - 30_000,
    score: 2,
    text: 'This comment has enough useful context to be eligible.',
    nsfw: false,
    parentPostId,
    distinguished: null,
    removed: false,
  };
}

describe('AccountBrowsingSimulationService', () => {
  let db: Database.Database;
  let repository: AccountBrowsingSimulationRepository;

  beforeEach(() => {
    db = new Database(':memory:');
    db.pragma('foreign_keys = ON');
    runMigrations(db);
    insertAccount(db, ACCOUNT, 'owner');
    insertAccount(db, OTHER, 'other');
    repository = new AccountBrowsingSimulationRepository(db);
  });

  function service(options: {
    posts?: RedditPost[];
    comments?: BrowsingThing[];
    random?: number;
    voter?: { upvote: ReturnType<typeof vi.fn> };
  } = {}) {
    const getHotPosts = vi.fn().mockResolvedValue(options.posts ?? [post('one')]);
    const getBrowsingComments = vi.fn().mockResolvedValue(options.comments ?? []);
    const instance = new AccountBrowsingSimulationService({
      accountId: ACCOUNT,
      repository,
      growthSubreddits: () => [{ subreddit: 'AskUK', weight: 1 }] as never,
      reddit: { getHotPosts, getBrowsingComments },
      sink: repository,
      voter: options.voter,
      logger: createMockLogger(),
      now: () => NOW,
      random: () => options.random ?? 0,
    });
    return { instance, getHotPosts, getBrowsingComments };
  }

  function enable(overrides: Parameters<AccountBrowsingSimulationRepository['saveSettings']>[1] = {}): void {
    repository.saveSettings(ACCOUNT, {
      enabled: true,
      quietHours: { enabled: false, startHour: 0, endHour: 7 },
      ...overrides,
    }, NOW - 1);
  }

  it('is disabled by default and performs no discovery', async () => {
    const fixture = service();

    await expect(fixture.instance.tick()).resolves.toEqual({
      kind: 'idle', reason: 'Browsing simulation is disabled',
    });
    expect(fixture.getHotPosts).not.toHaveBeenCalled();
  });

  it('persists a randomized due time that survives service recreation', async () => {
    enable({ minimumGapMs: 45 * 60_000, jitterMs: 10 * 60_000 });
    const first = service({ random: 0.5 });

    const scheduled = await first.instance.tick();
    const dueAt = repository.getSettings(ACCOUNT).nextDueAt;

    expect(scheduled).toEqual({ kind: 'scheduled', nextDueAt: dueAt });
    expect(dueAt).toBeGreaterThanOrEqual(NOW + 45 * 60_000);
    expect(dueAt).toBeLessThanOrEqual(NOW + 12 * 60 * 60_000);
    const restarted = service({ random: 0.1 });
    await expect(restarted.instance.tick()).resolves.toEqual({
      kind: 'idle', reason: 'Browsing simulation is not due',
    });
    expect(restarted.getHotPosts).not.toHaveBeenCalled();
  });

  it('records an eligible post as a simulation without any write transport', async () => {
    enable({ postWeight: 100, commentWeight: 0 });
    repository.setNextDueAt(ACCOUNT, NOW, NOW - 1);

    const result = await service().instance.tick();

    expect(result.kind).toBe('simulated');
    expect(repository.listRecent(ACCOUNT)).toEqual([
      expect.objectContaining({ thingFullname: 't3_one', decision: 'simulated-upvote' }),
    ]);
  });

  it('runs a requested simulation immediately without submitting a vote', async () => {
    enable({ postWeight: 100, commentWeight: 0 });
    const fixture = service();

    const result = await fixture.instance.runNow();

    expect(result).toMatchObject({
      kind: 'simulated', decision: { thingFullname: 't3_one', voteSubmitted: false },
    });
    expect(fixture.getHotPosts).toHaveBeenCalledOnce();
  });

  it('honours comment weighting when eligible comments exist', async () => {
    enable({ postWeight: 0, commentWeight: 100 });
    repository.setNextDueAt(ACCOUNT, NOW, NOW - 1);

    const result = await service({ comments: [comment('c1', 'one')] }).instance.tick();

    expect(result).toMatchObject({
      kind: 'simulated', decision: { thingFullname: 't1_c1', thingKind: 'comment' },
    });
  });

  it('submits the selected upvote only when the automatic action is enabled and allowed', async () => {
    enable({ postWeight: 100, commentWeight: 0, autoVoteEnabled: true });
    repository.setNextDueAt(ACCOUNT, NOW, NOW - 1);
    const voter = { upvote: vi.fn().mockResolvedValue({ status: 'submitted' }) };

    const result = await service({ voter }).instance.tick({ allowVoting: true });

    expect(voter.upvote).toHaveBeenCalledWith('t3_one');
    expect(result).toMatchObject({ kind: 'simulated', decision: { voteSubmitted: true, reason: 'Reddit upvote submitted' } });
    expect(repository.listRecentSelections(ACCOUNT)).toEqual([
      expect.objectContaining({ thingFullname: 't3_one', voteSubmitted: true }),
    ]);
  });

  it('keeps automatic voting disabled during a simulation-only pass', async () => {
    enable({ postWeight: 100, commentWeight: 0, autoVoteEnabled: true });
    repository.setNextDueAt(ACCOUNT, NOW, NOW - 1);
    const voter = { upvote: vi.fn().mockResolvedValue({ status: 'submitted' }) };

    const result = await service({ voter }).instance.tick();

    expect(voter.upvote).not.toHaveBeenCalled();
    expect(result).toMatchObject({ kind: 'simulated', decision: { voteSubmitted: false } });
  });

  it('rejects owned authors, outreach recipients, NSFW and cross-account duplicates', async () => {
    db.prepare(`INSERT INTO recipient_suppressions (recipient, reason, created_at) VALUES ('contacted', 'test', 0)`).run();
    const otherSelection: BrowsingDecisionRecord = {
      accountId: OTHER, thingFullname: 't3_taken', thingKind: 'post', postId: 'taken',
      subreddit: 'AskUK', author: 'someone', permalink: '/taken', decision: 'simulated-upvote',
      reason: 'test', discoveredAt: NOW - 1, decidedAt: NOW - 1, scheduledSessionId: 'other', voteSubmitted: false,
    };
    repository.recordDecision(otherSelection);
    enable({ postWeight: 100, commentWeight: 0, allowNsfw: false });
    repository.setNextDueAt(ACCOUNT, NOW, NOW - 1);
    const posts = [
      post('owned', { author: 'owner' }),
      post('recipient', { author: 'contacted' }),
      post('adult', { over_18: true }),
      post('taken'),
      post('allowed'),
    ];

    const result = await service({ posts }).instance.tick();

    expect(result).toMatchObject({ kind: 'simulated', decision: { thingFullname: 't3_allowed' } });
    const recent = repository.listRecent(ACCOUNT, 20);
    expect(recent.filter((entry) => entry.decision === 'rejected').map((entry) => entry.reason))
      .toEqual(expect.arrayContaining([
        'Authored by an owned account',
        'Authored by an outreach recipient',
        'NSFW content is disabled',
        'Already selected by another owned account',
      ]));
  });

  it('atomically prevents two accounts from recording the same simulated selection', async () => {
    const first: BrowsingDecisionRecord = {
      accountId: ACCOUNT, thingFullname: 't3_same', thingKind: 'post', postId: 'same',
      subreddit: 'AskUK', author: 'author', permalink: '/same', decision: 'simulated-upvote',
      reason: 'test', discoveredAt: NOW, decidedAt: NOW, scheduledSessionId: 'first', voteSubmitted: false,
    };
    expect(repository.recordDecision(first)).toBe(true);
    expect(repository.recordDecision({ ...first, accountId: OTHER, scheduledSessionId: 'second' }))
      .toBe(false);
  });

  it('stops at the deterministic daily target before making a Reddit request', async () => {
    enable({ dailyTargetMin: 1, dailyTargetMax: 1 });
    repository.recordDecision({
      accountId: ACCOUNT, thingFullname: 't3_done', thingKind: 'post', postId: 'done',
      subreddit: 'AskUK', author: 'author', permalink: '/done', decision: 'simulated-upvote',
      reason: 'test', discoveredAt: NOW - 1, decidedAt: NOW - 1, scheduledSessionId: 'done', voteSubmitted: false,
    });
    repository.setNextDueAt(ACCOUNT, NOW, NOW - 1);
    const fixture = service();

    expect(await fixture.instance.tick()).toMatchObject({ kind: 'scheduled' });
    expect(fixture.getHotPosts).not.toHaveBeenCalled();
  });
});

describe('browsing pacing policy', () => {
  it('handles quiet hours that cross midnight', () => {
    const settings = { quietHours: { enabled: true, startHour: 23, endHour: 7 } };
    expect(isQuietTime(new Date(2026, 7, 11, 23, 30), settings)).toBe(true);
    expect(isQuietTime(new Date(2026, 7, 12, 6, 59), settings)).toBe(true);
    expect(isQuietTime(new Date(2026, 7, 12, 7, 0), settings)).toBe(false);
  });

  it('derives one stable bounded target per account and local day', () => {
    const settings = { dailyTargetMin: 3, dailyTargetMax: 6 };
    const first = dailyTarget(ACCOUNT, NOW, settings);
    expect(dailyTarget(ACCOUNT, NOW, settings)).toBe(first);
    expect(first).toBeGreaterThanOrEqual(3);
    expect(first).toBeLessThanOrEqual(6);
  });
});

describe('browsing migration', () => {
  it('upgrades the previous production schema without disturbing growth settings', () => {
    const db = new Database(':memory:');
    db.pragma('foreign_keys = ON');
    runMigrations(db);
    const version = db.pragma('user_version', { simple: true }) as number;
    db.exec('DROP TABLE account_browsing_decisions; DROP TABLE account_browsing_settings;');
    db.pragma(`user_version = ${version - 2}`);

    runMigrations(db);
    insertAccount(db, ACCOUNT, 'owner');

    expect(new AccountBrowsingSimulationRepository(db).getSettings(ACCOUNT)).toMatchObject({
      enabled: false, dailyTargetMin: 3, dailyTargetMax: 6, nextDueAt: null,
    });
    expect(db.prepare(`PRAGMA table_info(account_growth_settings)`).all())
      .toEqual(expect.arrayContaining([expect.objectContaining({ name: 'daily_limit' })]));
  });
});