feat: add generic number format (#6664)

## Explanation

Add a generic `formatNumber` option to allow clients flexibility while
using the formatting cache.

## References

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## Checklist

- [x] I've updated the test suite for new or updated code as appropriate
- [x] I've updated documentation (JSDoc, Markdown, etc.) for new or
updated code as appropriate
- [x] I've communicated my changes to consumers by [updating changelogs
for packages I've
changed](https://github.com/MetaMask/core/tree/main/docs/contributing.md#updating-changelogs),
highlighting breaking changes as necessary
- [x] I've prepared draft pull requests for clients and consumer
packages to resolve any breaking changes

Author: n3ps

packages/assets-controllers/src/utils/formatters.test.ts

@@ -8,6 +8,27 @@ const invalidValues = [
   Number.NEGATIVE_INFINITY,
 ];
 
+describe('formatNumber', () => {
+  const { formatNumber } = createFormatters({ locale });
+
+  it('formats a basic integer', () => {
+    expect(formatNumber(1234)).toBe('1,234');
+  });
+
+  it('respects fraction digit options', () => {
+    expect(
+      formatNumber(1.2345, {
+        minimumFractionDigits: 2,
+        maximumFractionDigits: 2,
+      }),
+    ).toBe('1.23');
+  });
+
+  it('returns empty string for invalid number', () => {
+    expect(formatNumber(NaN)).toBe('');
+  });
+});
+
 describe('formatCurrency', () => {
   const { formatCurrency } = createFormatters({ locale });
 

packages/assets-controllers/src/utils/formatters.ts

@@ -51,6 +51,30 @@ function getCachedNumberFormat(
   return format;
 }
 
+/**
+ * Format a number with optional Intl overrides.
+ *
+ * @param config - Configuration object with locale.
+ * @param config.locale - Locale string.
+ * @param value - Numeric value to format.
+ * @param options - Optional Intl.NumberFormat overrides.
+ * @returns Formatted number string.
+ */
+function formatNumber(
+  config: { locale: string },
+  value: number | bigint | `${number}`,
+  options: Intl.NumberFormatOptions = {},
+) {
+  if (!Number.isFinite(Number(value))) {
+    return '';
+  }
+
+  const numberFormat = getCachedNumberFormat(config.locale, options);
+
+  // @ts-expect-error Remove this comment once TypeScript is updated to 5.5+
+  return numberFormat.format(value);
+}
+
 /**
  * Format a value as a currency string.
  *
@@ -260,6 +284,13 @@ function formatTokenQuantity(
  */
 export function createFormatters({ locale = FALLBACK_LOCALE }) {
   return {
+    /**
+     * Format a number with optional Intl overrides.
+     *
+     * @param value - Numeric value to format.
+     * @param options - Optional Intl.NumberFormat overrides.
+     */
+    formatNumber: formatNumber.bind(null, { locale }),
     /**
      * Format a value as a currency string.
      *