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Typed Data Tables

The default LIST_OF_OBJECT_PARAMS data-table mode — Gherkin data tables generate type-safe inner classes with typed accessors. No Cucumber dependency.

Source: examples/common-use-cases/example-1 on GitHub.

What this demonstrates​

  • Data tables generate inner Param classes (named after the last word of the step text + Param)
  • Column headers become typed fields with automatic type inference
  • Per-column inference: Integer, Double, Boolean, String, …
  • Readable headers (e.g. unit price) are sanitised to Java field names (unitPrice)
  • Each row becomes a new XxxParam(...) call inside List.of(...)
  • Multiple data tables in the same feature produce separate inner classes

The Gherkin​

Given my cart contains the following products:
  | name                | qty | unit price | in stock |
  | Wireless Headphones | 1   | 59.99      | true     |
  | Coffee Beans 1kg    | 3   | 12.50      | true     |
  | USB-C Cable         | 2   | 8.99       | false    |

The generated inner class​

public static class ProductsParam {
    private final String name;
    private final Integer qty;
    private final Double unitPrice;
    private final Boolean inStock;

    public ProductsParam(String name, Integer qty, Double unitPrice, Boolean inStock) {
        this.name = name;
        this.qty = qty;
        this.unitPrice = unitPrice;
        this.inStock = inStock;
    }

    public String  name()      { return this.name; }
    public Integer qty()       { return this.qty; }
    public Double  unitPrice() { return this.unitPrice; }
    public Boolean inStock()   { return this.inStock; }
}

The generated step method and call site​

// Step method signature
public abstract void myCartContainsTheFollowingProducts(List<ProductsParam> products);

// Generated call site
myCartContainsTheFollowingProducts(
        List.of(
                new ProductsParam("Wireless Headphones", 1, 59.99, true),
                new ProductsParam("Coffee Beans 1kg",    3, 12.50, true),
                new ProductsParam("USB-C Cable",         2,  8.99, false)
        ));

Key points​

  • Each unique data table shape in a feature produces its own Param class
  • Field accessors use record-style names (name(), not getName())
  • No Cucumber dependency — these are plain Java classes
  • For compile-time enum safety on a column, see Type Refinement

Run it​

cd examples/common-use-cases/example-1
mvn test