Code Generation

phpspec generates specs, classes, interfaces, method stubs, and step definitions to accelerate the spec-first workflow.

The describe command

Generate a spec for a class:

$ bin/phpspec describe App/Calculator

Creates spec/App/Calculator.spec.php with a template:

<?php
use App\Calculator;

describe(Calculator::class, function() {
    let("calculator", fn() => new Calculator());
    it("instantiates", fn() =>
        expect($this->calculator)->toBeAnInstanceOf(Calculator::class)
    );
});

With a method example

$ bin/phpspec describe App/Calculator -e add

Generates a spec that includes an example for the add method.

The exemplify command

Add a method example to an existing spec:

$ bin/phpspec exemplify App/Calculator add

If the spec doesn’t exist, it creates one.

Auto-class generation

When specs reference a class that doesn’t exist, phpspec’s custom autoloader prompts:

Looks like you are trying to spec App\Calculator,
a class that doesn't exist yet.
Would you like me to generate that class for you? [y/n] y

Generated class at src/App/Calculator.php:

<?php
namespace App;

class Calculator
{

}

Interface generation

When mock() references a class that doesn’t exist, phpspec offers to generate an interface:

Looks like you are trying to mock App\UserRepository,
a class that doesn't exist yet.
Would you like me to generate that interface for you? [y/n] y

When a mock calls a method that doesn’t exist on the interface, phpspec offers to add it.

Method stub generation

When specs call methods that don’t exist on a class, phpspec generates method stubs:

// Spec calls add() which doesn't exist yet:
expect($calc->add(2, 3))->toBe(5);

phpspec generates:

public function add()
{
}

--fake mode

Go beyond empty stubs — generate method bodies with hardcoded return values from your spec expectations:

$ bin/phpspec run --fake

Given the spec expectation expect($calc->add(2, 3))->toBe(5), phpspec generates:

public function add()
{
    return 5;
}

This creates a quick feedback loop: write spec, run with --fake, get passing tests immediately, then replace the faked implementation with real logic.

Step definition generation

When running feature files with undefined steps, phpspec generates step definition stubs. See Features & Steps.

The BDD cycle

phpspec’s code generation creates a natural workflow:

1. Write a spec — bin/phpspec describe App/Calculator
2. Run specs — phpspec prompts to generate the missing class
3. Add examples — write expect($calc->add(2, 3))->toBe(5)
4. Run again — phpspec offers to generate the add() method
5. Implement — fill in the real logic (or use --fake for a quick pass)
6. Repeat — add more examples, drive the design through specs