Shortened the table's "Values" with k, m and bn suffixes

web/src/lib/format.test.ts

@@ -5,6 +5,7 @@ import {
   formatDate,
   formatDateTime,
   formatMoney,
+  formatMoneyShort,
   formatValue,
   parseDate,
 } from './format';
@@ -34,6 +35,21 @@ test('money is shown in whole pounds, and nothing as a dash', () => {
   expect(formatMoney(-5)).toBe('—');
 });
 
+test.each([
+  { value: 1, want: '£1' },
+  { value: 500, want: '£500' },
+  { value: 3563, want: '£3.6k' },
+  { value: 12500, want: '£13k' },
+  { value: 583333, want: '£583k' },
+  { value: 1500000, want: '£1.5m' },
+  { value: 9621987, want: '£9.6m' },
+  { value: 36250000000, want: '£36bn' },
+  { value: 0, want: '—' },
+  { value: -5, want: '—' },
+])('formatMoneyShort shows $value as $want', ({ value, want }) => {
+  expect(formatMoneyShort(value)).toBe(want);
+});
+
 test('formatCount groups thousands', () => {
   expect(formatCount(4854)).toBe('4,854');
   expect(formatCount(7)).toBe('7');

web/src/lib/format.ts

@@ -22,6 +22,14 @@ const moneyFormat = new Intl.NumberFormat('en-GB', {
   maximumFractionDigits: 0,
 });
 
+// en-GB's compact suffixes are k, m and bn; amounts under £1,000 are left
+// whole.
+const shortMoneyFormat = new Intl.NumberFormat('en-GB', {
+  style: 'currency',
+  currency: 'GBP',
+  notation: 'compact',
+});
+
 const countFormat = new Intl.NumberFormat('en-GB');
 
 /** Treats null and Go's zero time.Time as "no date". */
@@ -48,6 +56,14 @@ export function formatMoney(value: number): string {
   return value > 0 ? moneyFormat.format(value) : '—';
 }
 
+/**
+ * An amount in pounds shortened with a suffix, e.g. "£250k", "£1.5m" or
+ * "£36bn", or a dash for none. Amounts under £1,000 are shown whole.
+ */
+export function formatMoneyShort(value: number): string {
+  return value > 0 ? shortMoneyFormat.format(value) : '—';
+}
+
 /** A count for display, e.g. "4,854". */
 export function formatCount(value: number): string {
   return countFormat.format(value);