Groczy

A grocery delivery app built with Flutter. Groczy turns browsing a grocery aisle into a few taps: shop by category, build a cart, pick a delivery slot, and watch your order move from placed to delivered - live.

Live preview: https://shaisolaris.github.io/flutter-groczy/

Screens

Screen	What it does
Shop	Category chips plus a searchable product grid - gradient-and-emoji tiles standing in for photography, each with a price, unit, and an "Add" button that becomes a quantity stepper once it's in the cart. Tap the heart to favorite a product.
Cart	Line items with quantity steppers, a day-by-day delivery slot picker (open/limited/full color-coded from live seed capacity), an editable delivery address, and an order summary - subtotal, delivery fee (free over $35), tax, and total, with a nudge banner showing how much more unlocks free delivery. Checkout books the order and opens a confirmation screen.
Orders	Past orders, most recent first, each with a live status tracker (Placed → Preparing → Out for delivery → Delivered) derived from how long ago it was placed - so a fresh order visibly progresses while a seeded past order always reads Delivered. Expand an order for its full receipt, or tap Reorder to merge it straight back into the cart.
Lists	Saved shopping lists - including Favorites, populated by the Shop screen's heart toggle - each with a preview strip and a one-tap "Add all to cart". Create new lists, or open one to remove individual items.

Navigation is a bottom bar with four tabs: Shop, Cart, Orders, Lists (the Cart tab carries a live item-count badge).

Architecture

lib/
  main.dart                  Entry point - loads SharedPreferences, wires ProviderScope
  app.dart                   MaterialApp, Material 3 theme (light + dark), bottom-nav shell
  core/
    models/                  Plain, JSON-serializable data classes (Product, CartItem, Order, ShoppingList, ...)
    logic/                   Pure, Flutter-free business logic (see Testing below)
    constants/                Gradient palette, date/money formatting, nav tab indices
    widgets/                  Small shared UI (gradient tile, quantity stepper, empty state, section header)
    utils/                    Dependency-free ID generation
  data/
    groczy_repository.dart    Storage interface + a shared_preferences-backed implementation
    seed_data.dart             Deterministic catalog + starter orders/lists (pure functions of "now")
    providers.dart             Riverpod providers/notifiers wiring the repository to the UI
  features/
    shop/     screen + widgets   Search, category chips, product grid
    cart/     screen + widgets   Line items, slot picker, order summary, checkout, confirmation
    orders/   screen + widgets   Order history, live status tracker, reorder
    lists/    screen + widgets   Saved lists, list detail sheet, create-list sheet

State management is flutter_riverpod, using AsyncNotifiers that load from - and persist back to - a small GroczyRepository abstraction. The UI never talks to shared_preferences directly, which keeps the storage layer swappable and easy to fake in tests. The cart, order history, and shopping lists are stored as JSON, each under its own key; the product catalog itself is read-only reference data rebuilt from seed_data.dart on every launch rather than persisted.

The cart totals, delivery-slot availability, order-status, reorder-merge, and catalog-filter math are all pure Dart with no Flutter dependency - they live entirely under lib/core/logic/ and are exercised directly by unit tests, independent of widgets or storage. Notably, an Order has no stored status field at all: core/logic/order_status.dart derives it fresh from placedAt every time it's displayed, so a freshly-checked-out order visibly advances through delivery stages purely from elapsed time.

Testing

test/
  core/logic/
    cart_test.dart             Subtotal, threshold-based delivery fee, tax, totals, cart-line resolution
    slots_test.dart             Deterministic slot generation, capacity/availability, day-relative labels
    reorder_test.dart           Merging a past order into the cart, including unavailable-product handling
    order_status_test.dart      Elapsed-time -> status thresholds, and the 4-stage progress sequence
    catalog_filter_test.dart    Category + search-query filtering, combined and independently
  data/
    seed_data_test.dart         The seeded catalog/orders/lists are deterministic and match a
                                 fully hand-traced breakdown (including exact order totals)
  widget_test.dart              App launches, search/category filtering, add-to-cart, and a full
                                 add -> pick a slot -> checkout -> confirmation -> track order flow

Every pure-logic test asserts a hand-traced expected value - for example, the first seeded order's total is checked against $41.04, computed by hand in the test's comments (subtotal $33.38 + delivery fee $4.99 + tax $2.67) rather than just against whatever the function happens to return.

flutter test

Run it

flutter pub get
flutter run                          # any connected device/simulator
flutter run -d chrome                # web
flutter build web --base-href /flutter-groczy/

Tech stack

• Flutter 3.24+, null-safe Dart, Material 3 (seed color #16A34A, light + dark)
• flutter_riverpod for state management
• shared_preferences for local, on-device persistence
• Zero third-party UI or date-formatting dependencies

License

MIT - see LICENSE.

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Author: Shai