feat: bootstrap BoxBrain foundation

tests/timing.test.ts

@@ -0,0 +1,47 @@
+import { describe, expect, it } from 'vitest';
+import {
+  createReplyDelay,
+  createTypingDelay,
+  DND_AVAILABILITY,
+  OFFLINE_AVAILABILITY,
+  ONLINE_AVAILABILITY,
+} from '../src/timing';
+
+describe('createTypingDelay', () => {
+  it('uses 0.05 to 0.08 seconds per character by default', () => {
+    expect(createTypingDelay('12345', { rng: () => 0 })).toBe(0.25);
+    expect(createTypingDelay('12345', { rng: () => 1 })).toBe(0.4);
+    expect(createTypingDelay('12345', { rng: () => 0.5 })).toBeCloseTo(0.325);
+  });
+
+  it('returns zero for empty messages', () => {
+    expect(createTypingDelay('', { rng: () => 1 })).toBe(0);
+  });
+});
+
+describe('createReplyDelay', () => {
+  it('does not add availability delay after the first reply in an active exchange', () => {
+    expect(createReplyDelay(ONLINE_AVAILABILITY, { isFirstReplyInExchange: false, rng: () => 1 })).toBe(0);
+    expect(createReplyDelay(DND_AVAILABILITY, { isFirstReplyInExchange: false, rng: () => 1 })).toBe(0);
+  });
+
+  it('adds an online first-reply delay from the configured range', () => {
+    expect(createReplyDelay(ONLINE_AVAILABILITY, { isFirstReplyInExchange: true, rng: () => 0 })).toBe(1);
+    expect(createReplyDelay(ONLINE_AVAILABILITY, { isFirstReplyInExchange: true, rng: () => 1 })).toBe(12);
+  });
+
+  it('can skip do-not-disturb first replies when probability fails', () => {
+    expect(createReplyDelay(DND_AVAILABILITY, { isFirstReplyInExchange: true, rng: () => 0.99 })).toBeNull();
+  });
+
+  it('returns a do-not-disturb delay when probability succeeds', () => {
+    const values = [0.1, 0.5];
+    const rng = () => values.shift() ?? 0;
+
+    expect(createReplyDelay(DND_AVAILABILITY, { isFirstReplyInExchange: true, rng })).toBe(330);
+  });
+
+  it('blocks offline replies', () => {
+    expect(createReplyDelay(OFFLINE_AVAILABILITY, { isFirstReplyInExchange: true, rng: () => 0 })).toBeNull();
+  });
+});