Files
kooltab/test/tab_money_test.dart

357 lines
12 KiB
Dart

import 'dart:math';
import 'package:drift/drift.dart' hide isNull, isNotNull;
import 'package:drift/native.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:kooltap/database/app_database.dart';
import 'package:kooltap/models/payment_method.dart';
import 'package:kooltap/models/product.dart';
import 'package:kooltap/services/bar_tab_service.dart';
import 'package:kooltap/services/product_service.dart';
const _beer = Product(
id: 'beer',
name: 'Beer',
category: 'Drinks',
stockQuantity: 50,
lowStockThreshold: 5,
priceInCents: 250,
);
const _wine = Product(
id: 'wine',
name: 'Wine',
category: 'Drinks',
stockQuantity: 20,
lowStockThreshold: 5,
priceInCents: 450,
);
const _water = Product(
id: 'water',
name: 'Tap water',
category: 'Drinks',
stockQuantity: 0,
lowStockThreshold: 0,
infiniteStock: true,
priceInCents: 0,
);
/// End-to-end checks on what customers are charged and what leaves the
/// fridge, against a real (in-memory) database.
void main() {
late AppDatabase database;
late DriftBarTabService tabs;
late DriftProductService products;
Future<void> insertProduct(Product product) {
return database
.into(database.products)
.insert(
ProductsCompanion.insert(
id: product.id,
name: product.name,
category: product.category,
stockQuantity: product.stockQuantity,
lowStockThreshold: product.lowStockThreshold,
infiniteStock: Value(product.infiniteStock),
priceInCents: product.priceInCents,
),
);
}
Future<int> stockOf(String productId) async {
return (await products.getProductById(productId))!.stockQuantity;
}
Future<int> quantityOnOpenTabs(String productId) async {
final open = await tabs.getOpenTabs();
return open
.expand((tab) => tab.items)
.where((item) => item.productId == productId)
.fold<int>(0, (sum, item) => sum + item.quantity);
}
Future<int> soldInHistory(String productId) async {
final closed = await tabs.getClosedTabs();
return closed
.expand((tab) => tab.items)
.where((item) => item.productId == productId && !item.isRemoved)
.fold<int>(0, (sum, item) => sum + item.quantity);
}
Future<String> itemId(String tabId, String productId) async {
final tab = (await tabs.getTabById(tabId))!;
return tab.items.firstWhere((item) => item.productId == productId).id;
}
setUp(() async {
database = AppDatabase(NativeDatabase.memory());
tabs = DriftBarTabService(database: database);
products = DriftProductService(database: database);
await insertProduct(_beer);
await insertProduct(_wine);
await insertProduct(_water);
});
tearDown(() async {
await database.close();
});
group('closing a tab', () {
test('charges exactly what the open tab showed', () async {
final tab = await tabs.createTab(customerName: 'John');
for (var i = 0; i < 3; i++) {
await tabs.addProductToTab(tabId: tab.id, product: _beer);
}
await tabs.addProductToTab(tabId: tab.id, product: _wine);
await tabs.adjustTabItemQuantity(
tabItemId: await itemId(tab.id, 'beer'),
delta: -1,
);
final open = (await tabs.getTabById(tab.id))!;
expect(open.totalInCents, 2 * 250 + 450);
await tabs.closeTab(tab.id, paymentMethod: PaymentMethod.payconiq);
final closed = (await tabs.getClosedTabs()).single;
expect(closed.totalInCents, open.totalInCents);
expect(closed.itemCount, open.itemCount);
expect(closed.paymentMethod, PaymentMethod.payconiq);
expect(closed.items.where((item) => item.isRemoved), hasLength(1));
});
test('stores each payment method as chosen', () async {
for (final method in PaymentMethod.values) {
final tab = await tabs.createTab(customerName: method.name);
await tabs.addProductToTab(tabId: tab.id, product: _beer);
await tabs.closeTab(tab.id, paymentMethod: method);
}
final closed = await tabs.getClosedTabs();
expect(
{for (final tab in closed) tab.customerName: tab.paymentMethod},
{for (final method in PaymentMethod.values) method.name: method},
);
});
test('does not record anything for an empty tab', () async {
final tab = await tabs.createTab(customerName: 'John');
await tabs.closeTab(tab.id);
expect(await tabs.getClosedTabs(), isEmpty);
});
test('records a tab whose drinks were all undone at zero', () async {
final tab = await tabs.createTab(customerName: 'John');
await tabs.addProductToTab(tabId: tab.id, product: _beer);
await tabs.adjustTabItemQuantity(
tabItemId: await itemId(tab.id, 'beer'),
delta: -1,
);
await tabs.closeTab(tab.id);
final closed = (await tabs.getClosedTabs()).single;
expect(closed.totalInCents, 0);
expect(closed.items.single.isRemoved, true);
});
test('never charges the same drink twice', () async {
final tab = await tabs.createTab(customerName: 'John');
await tabs.addProductToTab(tabId: tab.id, product: _beer);
await tabs.closeTab(tab.id);
await tabs.addProductToTab(tabId: tab.id, product: _wine);
await tabs.closeTab(tab.id);
await tabs.closeTab(tab.id);
final closed = await tabs.getClosedTabs();
expect(closed, hasLength(2));
expect(
closed.map((tab) => tab.totalInCents),
unorderedEquals([250, 450]),
);
expect((await tabs.getTabById(tab.id))!.items, isEmpty);
});
test('keeps the tab open under the same name', () async {
final tab = await tabs.createTab(customerName: 'John');
await tabs.addProductToTab(tabId: tab.id, product: _beer);
await tabs.closeTab(tab.id);
final reopened = (await tabs.getTabById(tab.id))!;
expect(reopened.customerName, 'John');
expect(reopened.totalInCents, 0);
});
test('a failed version check changes nothing', () async {
final tab = await tabs.createTab(customerName: 'John');
await tabs.addProductToTab(tabId: tab.id, product: _beer);
final staleVersion = (await tabs.getTabById(tab.id))!.version;
await tabs.addProductToTab(tabId: tab.id, product: _beer);
await expectLater(
tabs.closeTab(tab.id, expectedVersion: staleVersion),
throwsA(isA<TabVersionConflictException>()),
);
expect(await tabs.getClosedTabs(), isEmpty);
expect((await tabs.getTabById(tab.id))!.totalInCents, 500);
});
});
group('prices', () {
test('a tab keeps the price a drink was rung up at', () async {
final tab = await tabs.createTab(customerName: 'John');
await tabs.addProductToTab(tabId: tab.id, product: _beer);
await products.updateProduct(_beer.copyWith(priceInCents: 300));
await tabs.closeTab(tab.id);
expect((await tabs.getClosedTabs()).single.totalInCents, 250);
});
test('a new tab uses the current price', () async {
final updated = _beer.copyWith(priceInCents: 300);
await products.updateProduct(updated);
final tab = await tabs.createTab(customerName: 'Jane');
await tabs.addProductToTab(tabId: tab.id, product: updated);
expect((await tabs.getTabById(tab.id))!.totalInCents, 300);
});
test('free products add nothing to the total', () async {
final tab = await tabs.createTab(customerName: 'John');
await tabs.addProductToTab(tabId: tab.id, product: _water);
await tabs.addProductToTab(tabId: tab.id, product: _beer);
final open = (await tabs.getTabById(tab.id))!;
expect(open.totalInCents, 250);
expect(open.itemCount, 2);
});
});
group('stock', () {
test('every bottle is either in the fridge, on a tab or sold', () async {
final random = Random(42);
final tabIds = [
for (final name in ['A', 'B', 'C', 'D'])
(await tabs.createTab(customerName: name)).id,
];
for (var step = 0; step < 300; step++) {
final tabId = tabIds[random.nextInt(tabIds.length)];
final product = random.nextBool() ? _beer : _wine;
// Running out is part of the scenario: the stock goes negative
switch (random.nextInt(10)) {
case < 6:
await tabs.addProductToTab(tabId: tabId, product: product);
case < 8:
final tab = (await tabs.getTabById(tabId))!;
if (tab.items.isEmpty) continue;
final item = tab.items[random.nextInt(tab.items.length)];
await tabs.adjustTabItemQuantity(
tabItemId: item.id,
delta: random.nextInt(5) - 2,
);
case 8:
await tabs.closeTab(tabId);
default:
await tabs.deleteTab(tabId);
tabIds.remove(tabId);
tabIds.add((await tabs.createTab(customerName: 'New')).id);
}
for (final product in [_beer, _wine]) {
final accounted =
await stockOf(product.id) +
await quantityOnOpenTabs(product.id) +
await soldInHistory(product.id);
expect(accounted, product.stockQuantity, reason: 'step $step');
}
}
});
test('keeps selling when the stock runs out', () async {
final tab = await tabs.createTab(customerName: 'John');
for (var i = 0; i < _wine.stockQuantity + 5; i++) {
await tabs.addProductToTab(tabId: tab.id, product: _wine);
}
expect(await stockOf('wine'), -5);
expect((await tabs.getTabById(tab.id))!.totalInCents, 25 * 450);
});
test('simultaneous orders for the last bottle both go through', () async {
await products.updateProduct(_wine.copyWith(stockQuantity: 1));
final first = await tabs.createTab(customerName: 'A');
final second = await tabs.createTab(customerName: 'B');
await Future.wait([
for (final tab in [first, second])
tabs.addProductToTab(tabId: tab.id, product: _wine),
]);
expect(await stockOf('wine'), -1);
expect(await quantityOnOpenTabs('wine'), 2);
});
test('raising a quantity past the stock goes below zero', () async {
await products.updateProduct(_wine.copyWith(stockQuantity: 2));
final tab = await tabs.createTab(customerName: 'John');
await tabs.addProductToTab(tabId: tab.id, product: _wine);
final applied = await tabs.adjustTabItemQuantity(
tabItemId: await itemId(tab.id, 'wine'),
delta: 5,
);
expect(applied, 5);
expect(await stockOf('wine'), -4);
expect((await tabs.getTabById(tab.id))!.items.single.quantity, 6);
});
test('lowering past zero only returns what was on the tab', () async {
final tab = await tabs.createTab(customerName: 'John');
await tabs.addProductToTab(tabId: tab.id, product: _beer);
await tabs.addProductToTab(tabId: tab.id, product: _beer);
final applied = await tabs.adjustTabItemQuantity(
tabItemId: await itemId(tab.id, 'beer'),
delta: -10,
);
expect(applied, -2);
expect(await stockOf('beer'), _beer.stockQuantity);
});
test('closing a tab does not touch stock', () async {
final tab = await tabs.createTab(customerName: 'John');
await tabs.addProductToTab(tabId: tab.id, product: _beer);
await tabs.closeTab(tab.id);
expect(await stockOf('beer'), _beer.stockQuantity - 1);
});
test('infinite stock is never counted down or run out', () async {
final tab = await tabs.createTab(customerName: 'John');
for (var i = 0; i < 5; i++) {
await tabs.addProductToTab(tabId: tab.id, product: _water);
}
await tabs.deleteTab(tab.id);
expect(await stockOf('water'), 0);
});
});
}