toast-store.ts · Source

toast-store.tspackages/ui/src/toast-store.tsraw ← src3,490 B← Back to the app
1/**
2 * @factory/ui — toast store (PURE, injectable clock).
3 *
4 * Framework-agnostic observable list of toasts. Time is injected: `now()`
5 * and `schedule(fn, delayMs)` are constructor parameters, so tests drive
6 * expiry deterministically without real timers. The React `ToastProvider`
7 * (components/toast.tsx) is a thin renderer over this store.
8 */
9 
10export type ToastKind = "info" | "success" | "warning" | "error";
11 
12export interface Toast {
13  id: string;
14  kind: ToastKind;
15  message: string;
16  /** Expiry timestamp (ms) per the injected clock; 0 = sticky (no auto-dismiss). */
17  expiresAt: number;
18}
19 
20export interface ToastClock {
21  now(): number;
22  schedule(fn: () => void, delayMs: number): () => void;
23}
24 
25export interface ToastStoreOptions {
26  /** Default time-to-live in ms (default 5000). 0 → sticky. */
27  ttl?: number;
28  clock?: ToastClock;
29}
30 
31let nextId = 0;
32 
33/**
34 * Push/dismiss/subscribe with deterministic expiry:
35 *  - `push(kind, message, ttl?)` adds a toast, schedules its expiry via the
36 *    injected clock, and notifies subscribers.
37 *  - `dismiss(id)` removes it (and cancels its pending timer), notifies.
38 *  - Expiry is checked lazily too: `items()` never returns already-expired
39 *    toasts (safe under any clock skew / dropped timer).
40 *  - Subscribers receive the NEW snapshot array on every change.
41 */
42export class ToastStore {
43  readonly defaultTtl: number;
44  private readonly clock: ToastClock;
45  private readonly toasts: Toast[] = [];
46  private readonly timers = new Map<string, () => void>();
47  private readonly subscribers = new Set<(items: readonly Toast[]) => void>();
48 
49  constructor(options: ToastStoreOptions = {}) {
50    this.defaultTtl = options.ttl ?? 5000;
51    this.clock = options.clock ?? {
52      now: () => 0,
53      schedule: (fn) => {
54        fn();
55        return () => {};
56      },
57    };
58  }
59 
60  /** Current non-expired toasts (newest last). */
61  items(): readonly Toast[] {
62    const nowMs = this.clock.now();
63    for (let i = this.toasts.length - 1; i >= 0; i -= 1) {
64      const t = this.toasts[i];
65      if (t !== undefined && t.expiresAt > 0 && t.expiresAt <= nowMs) {
66        this.toasts.splice(i, 1);
67        this.timers.delete(t.id);
68      }
69    }
70    return this.toasts;
71  }
72 
73  /** Add a toast. `ttl` overrides the store default (ms; 0 = sticky). */
74  push(kind: ToastKind, message: string, ttl?: number): Toast {
75    const life = ttl ?? this.defaultTtl;
76    const id = `toast-${nextId++}`;
77    const expiresAt = life > 0 ? this.clock.now() + life : 0;
78    const toast: Toast = { id, kind, message, expiresAt };
79    this.toasts.push(toast);
80    if (life > 0) {
81      this.timers.set(
82        id,
83        this.clock.schedule(() => this.dismiss(id), life),
84      );
85    }
86    this.notify();
87    return toast;
88  }
89 
90  /** Remove a toast by id (no-op if unknown/expired). Returns true if removed. */
91  dismiss(id: string): boolean {
92    const idx = this.toasts.findIndex((t) => t.id === id);
93    if (idx < 0) return false;
94    this.toasts.splice(idx, 1);
95    const cancel = this.timers.get(id);
96    this.timers.delete(id);
97    cancel?.();
98    this.notify();
99    return true;
100  }
101 
102  /** Subscribe to snapshot changes; returns an unsubscribe function. */
103  subscribe(cb: (items: readonly Toast[]) => void): () => void {
104    this.subscribers.add(cb);
105    return () => {
106      this.subscribers.delete(cb);
107    };
108  }
109 
110  private notify(): void {
111    const snapshot = this.items();
112    for (const cb of this.subscribers) cb(snapshot);
113  }
114}
115