added prettier and eslint for dev

lib/formatters.ts

@@ -0,0 +1,80 @@
+export const formatCurrency = (
+  number: number,
+  currency: string,
+  locale: string | undefined = undefined
+): string => {
+  const CURRENCY_FORMATTER = new Intl.NumberFormat(locale, {
+    currency: currency,
+    style: 'currency'
+  })
+
+  return CURRENCY_FORMATTER.format(number)
+}
+
+export const formatNumber = (
+  number: number,
+  locale: string | undefined = undefined
+): string => {
+  const NUMBER_FORMATTER = new Intl.NumberFormat(locale)
+
+  return NUMBER_FORMATTER.format(number)
+}
+
+export const formatCompactNumber = (
+  number: number,
+  locale: string | undefined = undefined
+): string => {
+  const COMPACT_NUMBER_FORMATTER = new Intl.NumberFormat(locale, {
+    notation: 'compact'
+  })
+
+  return COMPACT_NUMBER_FORMATTER.format(number)
+}
+
+type DivisionsT = {
+  amount: number
+  name:
+    | 'year'
+    | 'years'
+    | 'quarter'
+    | 'quarters'
+    | 'month'
+    | 'months'
+    | 'week'
+    | 'weeks'
+    | 'day'
+    | 'days'
+    | 'hour'
+    | 'hours'
+    | 'minute'
+    | 'minutes'
+    | 'second'
+    | 'seconds'
+}
+const DIVISIONS: DivisionsT[] = [
+  { amount: 60, name: 'seconds' },
+  { amount: 60, name: 'minutes' },
+  { amount: 24, name: 'hours' },
+  { amount: 7, name: 'days' },
+  { amount: 4.34524, name: 'weeks' },
+  { amount: 12, name: 'months' },
+  { amount: Number.POSITIVE_INFINITY, name: 'years' }
+]
+export const formatRelativeDate = (
+  toDate: number,
+  fromDate: number = new Date().getSeconds(),
+  locale: string | undefined = undefined
+): string => {
+  const RELATIVE_DATE_FORMATTER = new Intl.RelativeTimeFormat(locale, {
+    numeric: 'auto'
+  })
+  let duration = (toDate - fromDate) / 1000
+
+  for (let i = 0; i <= DIVISIONS.length; i++) {
+    const division = DIVISIONS[i]
+    if (Math.abs(duration) < division.amount)
+      return RELATIVE_DATE_FORMATTER.format(Math.round(duration), division.name)
+
+    duration /= division.amount
+  }
+}