Init create/admin call links flow

ts/util/numbers.ts

@@ -0,0 +1,59 @@
+// Copyright 2024 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+import { strictAssert } from './assert';
+
+export function safeParseNumber(value: number | string): number | null {
+  if (typeof value === 'number') {
+    return value;
+  }
+  strictAssert(typeof value === 'string', 'Expected string or number');
+  const trimmed = value.trim();
+  if (trimmed === '') {
+    return null;
+  }
+  const parsed = Number(value);
+  if (!Number.isFinite(parsed)) {
+    return null;
+  }
+  if (parsed < Number.MIN_SAFE_INTEGER || parsed > Number.MAX_SAFE_INTEGER) {
+    return null;
+  }
+  return parsed;
+}
+
+export function safeParseInteger(
+  value: number | string,
+  trunc = false
+): number | null {
+  const parsed = safeParseNumber(value);
+  if (parsed == null) {
+    return null;
+  }
+  if (trunc) {
+    return Math.trunc(parsed);
+  }
+  if (!Number.isInteger(parsed)) {
+    return null;
+  }
+  return parsed;
+}
+
+export function safeParseBigint(
+  value: bigint | number | string
+): bigint | null {
+  if (typeof value === 'bigint') {
+    return value;
+  }
+  if (typeof value === 'number') {
+    if (!Number.isInteger(value)) {
+      return null;
+    }
+    return BigInt(value);
+  }
+  strictAssert(typeof value === 'string', 'Expected string, number, or bigint');
+  const trimmed = value.trim();
+  if (trimmed === '') {
+    return null;
+  }
+  return BigInt(value);
+}