[ARCHIVED] Order placement succeeds when product is out of stock

[valentinajemuovic]

Description

When a customer places an order for a product with a quantity greater than the available stock, the order is accepted and confirmed. The system does not validate stock levels at the time of order placement, leading to overselling.

Steps to Reproduce

Set a product's stock to 2 units
Place an order for 5 units of that product
Observe: order is confirmed with status "Accepted"
Expected Behaviour

The order should be rejected with an appropriate error message when the requested quantity exceeds available stock.

Acceptance Criteria

Scenario: Place order with sufficient stock
  Given a product with 10 units in stock
  When a customer places an order for 3 units
  Then the order should be accepted

Scenario: Place order with insufficient stock
  Given a product with 2 units in stock
  When a customer places an order for 5 units
  Then the order should be rejected
  And the error should indicate insufficient stock

Scenario: Place order for exact available quantity
  Given a product with 3 units in stock
  When a customer places an order for 3 units
  Then the order should be accepted

[valentinajemuovic]

AT - RED - DSL completed for Place order with sufficient stock.

DSL interface changes

• ReturnsProductRequest (driver-port/external/erp/dtos): added stockQuantity field (String)
• ReturnsProduct (dsl-core/app/external/erp/usecases): added stockQuantity(String) method; passes stockQuantity through to ReturnsProductRequest
• GivenProductImpl (dsl-core/scenario/given/steps): added stockQuantity field with default "100"; added withStockQuantity(String) method
• GivenProduct (dsl-port/given/steps): added withStockQuantity(String) to interface

Driver adapter changes

• ErpRealDriver and ErpStubDriver: returnsProduct() now throws UnsupportedOperationException("TODO: Driver") when stockQuantity is non-null (to be implemented in AT - RED - DRIVER)

Commit: 6330fb4f

[valentinajemuovic]

AT - RED - DRIVER — Driver changes for Place order with sufficient stock

• ExtCreateProductRequest: added stockQuantity field (String) to the ERP client request DTO
• ExtProductDetailsResponse: added stockQuantity field to the ERP client response DTO
• ErpStubDriver.returnsProduct(): now passes stockQuantity through to the ERP stub API
• ErpRealDriver.returnsProduct(): now passes stockQuantity through to the real ERP API

[valentinajemuovic]

CT - RED - DSL complete for Place order with sufficient stock.

DSL interface changes:

• GetProductVerification.stockQuantity(String) — implemented real assertion logic (was previously a TODO: DSL stub), verifies GetProductResponse.stockQuantity matches expected value
• GetProductResponse.stockQuantity field — already added in AT - RED - DSL phase
• ThenProduct.hasStockQuantity(String) — already wired in AT - RED - DSL phase

Driver change:

• BaseErpDriver.getProduct() — added stockQuantity(null) placeholder in response mapping (TODO: Driver — to be implemented in CT - RED - DRIVER)

[valentinajemuovic]

CT - RED - DRIVER — Driver changes summary:

• BaseErpDriver.getProduct() now maps stockQuantity from ExtProductDetailsResponse into GetProductResponse, completing the contract test driver layer for stock quantity retrieval from ERP.