Repository: symfony/symfony
File: src/Symfony/Component/Console/Command/Command.php (PHP)

Code before:
            $input->setArgument('command', $this->getName());
        }

        $input->validate();

        if ($this->code) {
            return ($this->code)($input, $output);
        }

        return $this->execute($input, $output);
    }

    /**
     * Supplies suggestions when resolving possible completion options for input (e.g. option or argument).
     */
    public function complete(CompletionInput $input, CompletionSuggestions $suggestions): void
    {
        $definition = $this->getDefinition();
        if (CompletionInput::TYPE_OPTION_VALUE === $input->getCompletionType() && $definition->hasOption($input->getCompletionName())) {
            $definition->getOption($input->getCompletionName())->complete($input, $suggestions);
        } elseif (CompletionInput::TYPE_ARGUMENT_VALUE === $input->getCompletionType() && $definition->hasArgument($input->getCompletionName())) {
            $definition->getArgument($input->getCompletionName())->complete($input, $suggestions);
        }
    }

    public function getCode(): ?InvokableCommand
    {
        return $this->code;
    }

    /**
     * Sets the code to execute when running this command.
     *
     * If this method is used, it overrides the code defined
     * in the execute() method.
     *
     * @param callable $code A callable(InputInterface $input, OutputInterface $output)
     *
     * @return $this
     *
     * @throws InvalidArgumentException
     *
     * @see execute()
     */
    public function setCode(callable $code): static
    {
        $this->code = new InvokableCommand($this, $code);

        return $this;
    }


Review comment (suggestion):
The `InvokableCommand` class in *internal*, we have to change that in order to use it as return type hint in the public API.

Code after:
    /**
     * Supplies suggestions when resolving possible completion options for input (e.g. option or argument).
     */
    public function complete(CompletionInput $input, CompletionSuggestions $suggestions): void
    {
        $definition = $this->getDefinition();
        if (CompletionInput::TYPE_OPTION_VALUE === $input->getCompletionType() && $definition->hasOption($input->getCompletionName())) {
            $definition->getOption($input->getCompletionName())->complete($input, $suggestions);
        } elseif (CompletionInput::TYPE_ARGUMENT_VALUE === $input->getCompletionType() && $definition->hasArgument($input->getCompletionName())) {
            $definition->getArgument($input->getCompletionName())->complete($input, $suggestions);
        }
    }

    /**
     * Gets the code that is executed by the command.
     *
     * @return ?callable null if the code has not been set with setCode()
     */
    public function getCode(): ?callable
    {
        return $this->code?->getCode();
    }

    /**
     * Sets the code to execute when running this command.
     *
     * If this method is used, it overrides the code defined
     * in the execute() method.
     *
     * @param callable $code A callable(InputInterface $input, OutputInterface $output)
     *
     * @return $this
     *
     * @throws InvalidArgumentException
     *
     * @see execute()
     */
    public function setCode(callable $code): static
    {
        $this->code = new InvokableCommand($this, $code);

        return $this;
    }

    /**
     * Merges the application definition with the command definition.
     *
     * This method is not part of public API and should not be used directly.
     *
     * @param bool $mergeArgs Whether to merge or not the Application definition arguments to Command definition arguments
     *