build: migrate to pnpm and add vitest testing infrastructure

- Replace Yarn with pnpm as package manager
- Add Vitest with React Testing Library and happy-dom
- Configure test setup and add test scripts (test, test:ui, test:run)
- Add IPCard component and update lookup components
- Remove unused react-ogp dependency
- Add type-check script

src/helpers.ts

@@ -40,3 +40,92 @@ export function truncated(input: string, maxLength: number, ellipsis = "...") {
 export function preventDefault(event: SyntheticEvent | Event) {
   event.preventDefault();
 }
+
+/**
+ * Convert an IPv4 address string to a 32-bit integer
+ */
+function ipv4ToInt(ip: string): number {
+  const parts = ip.split('.').map(Number);
+  if (parts.length !== 4) return 0;
+  const [a, b, c, d] = parts;
+  if (a === undefined || b === undefined || c === undefined || d === undefined) return 0;
+  return ((a << 24) | (b << 16) | (c << 8) | d) >>> 0;
+}
+
+/**
+ * Check if an IPv4 address falls within a CIDR range
+ * @param ip The IP address to check (e.g., "192.168.1.1")
+ * @param cidr The CIDR range to check against (e.g., "192.168.0.0/16")
+ * @returns true if the IP is within the CIDR range
+ */
+export function ipv4InCIDR(ip: string, cidr: string): boolean {
+  const [rangeIp, prefixLenStr] = cidr.split('/');
+  const prefixLen = parseInt(prefixLenStr ?? '', 10);
+
+  if (!rangeIp || isNaN(prefixLen) || prefixLen < 0 || prefixLen > 32) {
+    return false;
+  }
+
+  const ipInt = ipv4ToInt(ip);
+  const rangeInt = ipv4ToInt(rangeIp);
+  const mask = (0xFFFFFFFF << (32 - prefixLen)) >>> 0;
+
+  return (ipInt & mask) === (rangeInt & mask);
+}
+
+/**
+ * Convert an IPv6 address to a BigInt representation
+ */
+function ipv6ToBigInt(ip: string): bigint {
+  // Expand :: notation
+  const expandedIp = expandIPv6(ip);
+  const parts = expandedIp.split(':');
+
+  let result = BigInt(0);
+  for (const part of parts) {
+    result = (result << BigInt(16)) | BigInt(parseInt(part, 16));
+  }
+  return result;
+}
+
+/**
+ * Expand IPv6 address shorthand notation
+ */
+function expandIPv6(ip: string): string {
+  if (ip.includes('::')) {
+    const [left, right] = ip.split('::');
+    const leftParts = left ? left.split(':') : [];
+    const rightParts = right ? right.split(':') : [];
+    const missingParts = 8 - leftParts.length - rightParts.length;
+    const middleParts: string[] = Array(missingParts).fill('0') as string[];
+    const allParts = [...leftParts, ...middleParts, ...rightParts];
+    return allParts.map((p: string) => p.padStart(4, '0')).join(':');
+  }
+  return ip.split(':').map((p: string) => p.padStart(4, '0')).join(':');
+}
+
+/**
+ * Check if an IPv6 address falls within a CIDR range
+ * @param ip The IPv6 address to check (e.g., "2001:db8::1")
+ * @param cidr The CIDR range to check against (e.g., "2001:db8::/32")
+ * @returns true if the IP is within the CIDR range
+ */
+export function ipv6InCIDR(ip: string, cidr: string): boolean {
+  const [rangeIp, prefixLenStr] = cidr.split('/');
+  const prefixLen = parseInt(prefixLenStr ?? '', 10);
+
+  if (!rangeIp || isNaN(prefixLen) || prefixLen < 0 || prefixLen > 128) {
+    return false;
+  }
+
+  try {
+    const ipInt = ipv6ToBigInt(ip);
+    const rangeInt = ipv6ToBigInt(rangeIp);
+    const maxMask = BigInt('0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF');
+    const mask = (maxMask << BigInt(128 - prefixLen)) & maxMask;
+
+    return (ipInt & mask) === (rangeInt & mask);
+  } catch (e) {
+    return false;
+  }
+}