Initial donation amount picker

Co-authored-by: trevor-signal <131492920+trevor-signal@users.noreply.github.com>

ts/test-node/util/currency_test.ts

@@ -0,0 +1,166 @@
+// Copyright 2025 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { assert } from 'chai';
+
+import {
+  brandHumanDonationAmount,
+  brandStripeDonationAmount,
+  parseCurrencyString,
+  toHumanDonationAmount,
+  toHumanCurrencyString,
+  toStripeDonationAmount,
+} from '../../util/currency';
+
+describe('parseCurrencyString', () => {
+  function testFn(
+    { currency, value }: { currency: string; value: string },
+    expectedOutput: number | undefined
+  ): void {
+    const brandedOutput =
+      expectedOutput == null
+        ? undefined
+        : brandHumanDonationAmount(expectedOutput);
+    assert.equal(parseCurrencyString({ currency, value }), brandedOutput);
+  }
+
+  it('handles USD', () => {
+    testFn({ currency: 'usd', value: '10' }, 10);
+    testFn({ currency: 'usd', value: '10.0' }, 10);
+    testFn({ currency: 'usd', value: '10.00' }, 10);
+    testFn({ currency: 'usd', value: '10.000' }, 10);
+    testFn({ currency: 'usd', value: '10.50' }, 10.5);
+    testFn({ currency: 'usd', value: '10.6969' }, 10.69);
+    testFn({ currency: 'usd', value: '.69' }, 0.69);
+    testFn({ currency: 'usd', value: '0.69' }, 0.69);
+  });
+
+  it('handles JPY', () => {
+    testFn({ currency: 'jpy', value: '1000' }, 1000);
+    testFn({ currency: 'jpy', value: '1000.0' }, 1000);
+    testFn({ currency: 'jpy', value: '1000.5' }, 1000);
+    testFn({ currency: 'jpy', value: '1000.5555' }, 1000);
+  });
+
+  it('handles malformed input', () => {
+    testFn({ currency: 'usd', value: '' }, undefined);
+    testFn({ currency: 'usd', value: '??' }, undefined);
+    testFn({ currency: 'usd', value: '-50' }, undefined);
+    testFn({ currency: 'usd', value: 'abc' }, undefined);
+  });
+});
+
+describe('toHumanDonationAmount', () => {
+  function testFn(
+    { amount, currency }: { amount: number; currency: string },
+    expectedOutput: number
+  ): void {
+    const stripeAmount = brandStripeDonationAmount(amount);
+    const brandedOutput = brandHumanDonationAmount(expectedOutput);
+    assert.equal(
+      toHumanDonationAmount({ amount: stripeAmount, currency }),
+      brandedOutput
+    );
+  }
+
+  it('handles USD', () => {
+    testFn({ amount: 1000, currency: 'usd' }, 10);
+    testFn({ amount: 1000, currency: 'USD' }, 10);
+  });
+
+  it('handles JPY', () => {
+    testFn({ amount: 1000, currency: 'jpy' }, 1000);
+    testFn({ amount: 1000, currency: 'JPY' }, 1000);
+  });
+
+  it('handles KRW', () => {
+    testFn({ amount: 10000, currency: 'krw' }, 10000);
+    testFn({ amount: 10000, currency: 'KRW' }, 10000);
+  });
+});
+
+describe('toStripeDonationAmount', () => {
+  function testFn(
+    { amount, currency }: { amount: number; currency: string },
+    expectedOutput: number
+  ): void {
+    const humanAmount = brandHumanDonationAmount(amount);
+    const brandedOutput = brandStripeDonationAmount(expectedOutput);
+    assert.equal(
+      toStripeDonationAmount({ amount: humanAmount, currency }),
+      brandedOutput
+    );
+  }
+
+  it('handles USD', () => {
+    testFn({ amount: 10, currency: 'usd' }, 1000);
+    testFn({ amount: 10, currency: 'USD' }, 1000);
+  });
+
+  it('handles JPY', () => {
+    testFn({ amount: 1000, currency: 'jpy' }, 1000);
+    testFn({ amount: 1000, currency: 'JPY' }, 1000);
+  });
+
+  it('handles KRW', () => {
+    testFn({ amount: 10000, currency: 'krw' }, 10000);
+    testFn({ amount: 10000, currency: 'KRW' }, 10000);
+  });
+});
+
+describe('toHumanCurrencyString', () => {
+  function testFn(
+    {
+      amount,
+      currency,
+      showInsignificantFractionDigits = false,
+    }: {
+      amount: number;
+      currency: string;
+      showInsignificantFractionDigits?: boolean;
+    },
+    expectedOutput: string | undefined
+  ): void {
+    const humanAmount = brandHumanDonationAmount(amount);
+    assert.equal(
+      toHumanCurrencyString({
+        amount: humanAmount,
+        currency,
+        showInsignificantFractionDigits,
+      }),
+      expectedOutput
+    );
+  }
+
+  it('handles USD', () => {
+    testFn(
+      { amount: 10, currency: 'usd', showInsignificantFractionDigits: true },
+      '$10.00'
+    );
+    testFn({ amount: 10, currency: 'USD' }, '$10');
+    testFn({ amount: 10.5, currency: 'USD' }, '$10.50');
+    testFn({ amount: 10.5, currency: 'USD' }, '$10.50');
+    testFn({ amount: 10.69, currency: 'USD' }, '$10.69');
+  });
+
+  it('handles EUR', () => {
+    testFn(
+      { amount: 10, currency: 'eur', showInsignificantFractionDigits: true },
+      '€10.00'
+    );
+    testFn({ amount: 10, currency: 'eur' }, '€10');
+  });
+
+  it('handles JPY', () => {
+    testFn({ amount: 1000, currency: 'jpy' }, '¥1,000');
+    testFn(
+      { amount: 1000, currency: 'JPY', showInsignificantFractionDigits: true },
+      '¥1,000'
+    );
+  });
+
+  it('returns empty string for bad inputs', () => {
+    testFn({ amount: 10, currency: '420' }, '');
+    testFn({ amount: 10, currency: '' }, '');
+  });
+});