fix(utils): consolidate date and datetime formatting helpers (#28)

src/lib/utils.ts

@@ -30,7 +30,9 @@ function toClassArray(val: ClassValue): string[] {
 
 export function formatDate(iso: string, opts?: Intl.DateTimeFormatOptions): string {
   try {
-    return new Date(iso).toLocaleDateString('en-US', {
+    const d = new Date(iso)
+    if (isNaN(d.getTime())) return iso
+    return d.toLocaleDateString('en-US', {
       month: 'short',
       day: 'numeric',
       year: 'numeric',
@@ -43,7 +45,9 @@ export function formatDate(iso: string, opts?: Intl.DateTimeFormatOptions): stri
 
 export function formatDateTime(iso: string): string {
   try {
-    return new Date(iso).toLocaleString('en-US', {
+    const d = new Date(iso)
+    if (isNaN(d.getTime())) return iso
+    return d.toLocaleString('en-US', {
       month: 'short',
       day: 'numeric',
       year: 'numeric',
@@ -56,15 +60,21 @@ export function formatDateTime(iso: string): string {
 }
 
 export function timeAgo(iso: string): string {
-  const seconds = Math.floor((Date.now() - new Date(iso).getTime()) / 1000)
-  if (seconds < 60) return 'just now'
-  const minutes = Math.floor(seconds / 60)
-  if (minutes < 60) return `${minutes}m ago`
-  const hours = Math.floor(minutes / 60)
-  if (hours < 24) return `${hours}h ago`
-  const days = Math.floor(hours / 24)
-  if (days < 30) return `${days}d ago`
-  return formatDate(iso)
+  try {
+    const d = new Date(iso)
+    if (isNaN(d.getTime())) return iso
+    const seconds = Math.floor((Date.now() - d.getTime()) / 1000)
+    if (seconds < 60) return 'just now'
+    const minutes = Math.floor(seconds / 60)
+    if (minutes < 60) return `${minutes}m ago`
+    const hours = Math.floor(minutes / 60)
+    if (hours < 24) return `${hours}h ago`
+    const days = Math.floor(hours / 24)
+    if (days < 30) return `${days}d ago`
+    return formatDate(iso)
+  } catch {
+    return iso
+  }
 }
 
 // ─── Clipboard ────────────────────────────────────────────────────────────────

src/utils/format.test.ts

@@ -1,5 +1,5 @@
 import { describe, it, expect } from 'vitest'
-import { formatAmount, formatCurrency } from './format'
+import { formatAmount, formatCurrency, formatDate, formatDateTime } from './format'
 
 describe('formatAmount', () => {
   it('formats with 2 decimal places', () => expect(formatAmount(1234.5)).toBe('1,234.50'))
@@ -9,3 +9,32 @@ describe('formatAmount', () => {
 describe('formatCurrency', () => {
   it('formats USD', () => expect(formatCurrency(10)).toContain('10.00'))
 })
+
+describe('formatDate and formatDateTime consolidation (#28)', () => {
+  it('formats valid ISO date string without time', () => {
+    const res = formatDate('2026-07-15T12:00:00Z')
+    expect(res).toContain('Jul')
+    expect(res).toContain('15')
+    expect(res).toContain('2026')
+  })
+
+  it('formats Date instance', () => {
+    const d = new Date('2026-07-15T12:00:00Z')
+    const res = formatDate(d)
+    expect(res).toContain('Jul')
+    expect(res).toContain('15')
+    expect(res).toContain('2026')
+  })
+
+  it('formats valid ISO date string with time using formatDateTime', () => {
+    const res = formatDateTime('2026-07-15T12:00:00Z')
+    expect(res).toContain('Jul')
+    expect(res).toContain('15')
+    expect(res).toContain('2026')
+  })
+
+  it('gracefully returns unparseable string on invalid date input', () => {
+    expect(formatDate('not-a-date')).toBe('not-a-date')
+    expect(formatDateTime('invalid-date')).toBe('invalid-date')
+  })
+})

src/utils/format.ts

@@ -1,3 +1,19 @@
-export const formatAmount = (n: number, d = 2) => new Intl.NumberFormat('en-US', { minimumFractionDigits: d, maximumFractionDigits: d }).format(n)
-export const formatDate = (d: Date | string) => new Intl.DateTimeFormat('en-US', { year: 'numeric', month: 'short', day: 'numeric', hour: '2-digit', minute: '2-digit' }).format(new Date(d))
-export const formatCurrency = (n: number, c = 'USD') => new Intl.NumberFormat('en-US', { style: 'currency', currency: c }).format(n)
+import {
+  formatDate as libFormatDate,
+  formatDateTime as libFormatDateTime,
+} from '@/lib/utils'
+
+export const formatAmount = (n: number, d = 2) =>
+  new Intl.NumberFormat('en-US', {
+    minimumFractionDigits: d,
+    maximumFractionDigits: d,
+  }).format(n)
+
+export const formatDate = (d: Date | string, opts?: Intl.DateTimeFormatOptions) =>
+  libFormatDate(typeof d === 'string' ? d : d.toISOString(), opts)
+
+export const formatDateTime = (d: Date | string) =>
+  libFormatDateTime(typeof d === 'string' ? d : d.toISOString())
+
+export const formatCurrency = (n: number, c = 'USD') =>
+  new Intl.NumberFormat('en-US', { style: 'currency', currency: c }).format(n)