own version of toast

interface/src/components/toast/toastStore.ts

@@ -0,0 +1,47 @@
+export type ToastSeverity = 'success' | 'error' | 'info' | 'warning';
+
+export interface ToastItem {
+  id: number;
+  severity: ToastSeverity;
+  message: string;
+}
+
+let toasts: ToastItem[] = [];
+let nextId = 1;
+const listeners = new Set<() => void>();
+
+const emit = () => {
+  for (const listener of listeners) listener();
+};
+
+export const subscribe = (listener: () => void): (() => void) => {
+  listeners.add(listener);
+  return () => {
+    listeners.delete(listener);
+  };
+};
+
+export const getSnapshot = (): ToastItem[] => toasts;
+
+const add = (severity: ToastSeverity, message: string): number => {
+  const id = nextId++;
+  toasts = [...toasts, { id, severity, message }];
+  emit();
+  return id;
+};
+
+export const removeToast = (id: number): void => {
+  const next = toasts.filter((t) => t.id !== id);
+  if (next.length !== toasts.length) {
+    toasts = next;
+    emit();
+  }
+};
+
+// Imperative API mirroring the subset of react-toastify used across the app.
+export const toast = {
+  success: (message: string) => add('success', message),
+  error: (message: string) => add('error', message),
+  info: (message: string) => add('info', message),
+  warning: (message: string) => add('warning', message)
+};