Step Parameters

How quoted values in Gherkin steps become typed Java method parameters with automatic type inference.

Source: examples/getting-started/example-2 on GitHub.

What this demonstrates

• Each quoted value in a step ("59.99", "3", "true") becomes a method parameter
• The generator infers the parameter type from the value's shape
• Parameter slots are marked in the method name with $p1, $p2, $p3 placeholders
• Multiple parameters in a single step
• The concrete test class receives the values already typed and uses them directly, with no parsing

Type inference rules

Quoted value	Inferred type
"true" / "false"	Boolean
Integer literal (e.g. "3")	Integer (or Long if too large)
Decimal literal (e.g. "59.99")	Double
Single character (e.g. "Y")	Character
Everything else (e.g. "Wireless Headphones")	String

The feature file

src/test/resources/specs/ShoppingCart.feature

Scenario: Add item with quantity and price
  Given my cart contains "Wireless Headphones" with quantity "1" and unit price "59.99"
  When I change the quantity to "3"
  Then the cart subtotal should be "179.97"

Scenario: Apply a discount flag
  Given my cart contains "Coffee Beans" with quantity "2" and unit price "15.50"
  And the discount applied is "true"
  When I view the cart summary
  Then the discount badge shows "Y"

The generated step methods

public abstract void myCartContains$p1WithQuantity$p2AndUnitPrice$p3(String p1, Integer p2, Double p3);

public abstract void iChangeTheQuantityTo$p1(Integer p1);

public abstract void theCartSubtotalShouldBe$p1(Double p1);

public abstract void theDiscountAppliedIs$p1(Boolean p1);

public abstract void iViewTheCartSummary();

public abstract void theDiscountBadgeShows$p1(Character p1);

Each "…" token in the original step text becomes a parameter; the $p1, $p2, … placeholders in the method name mark where each parameter belongs. Identical step text under different keywords (Given / When / Then / And / But) reuses the same method.

The test class

ShoppingCartTest implements the abstract methods, so the step code works with real types:

ShoppingCartTest.java

@Override
public void iChangeTheQuantityTo$p1(Integer newQuantity) {
    quantity = newQuantity;
}

@Override
public void theCartSubtotalShouldBe$p1(Double expectedSubtotal) {
    assertEquals(expectedSubtotal, quantity * unitPrice, 0.001);
}

@Override
public void theDiscountAppliedIs$p1(Boolean applied) {
    discountApplied = applied;
}

@Override
public void theDiscountBadgeShows$p1(Character expectedBadge) {
    assertEquals(expectedBadge, discountBadge);
}

Parameter names in your implementation can be anything — only the method name and parameter types need to match the generated signature.

Run it

cd examples/getting-started/example-2
mvn test