Testing CLI Commands

Using MockInputOutput 

New in version 4.5.0.

MockInputOutput 

MockInputOutput provides an easy way to write tests for commands that require user input, such as CLI::prompt(), CLI::wait(), and CLI::input().

You can replace the InputOutput class with MockInputOutput during test execution to capture inputs and outputs.

Note

When you use MockInputOutput, you don’t need to use StreamFilterTrait, CITestStreamFilter, and PhpStreamWrapper.

Helper Methods 

getOutput(?int $index = null): string

Gets the output.

If you call it like $io->getOutput(), it returns the whole output string.
If you specify 0 or a positive number, it returns the output array item. Each item has the output of a CLI::fwrite() call.
If you specify a negative number -n, it returns the last n-th item of the output array.

getOutputs(): array

Returns the output array. Each item has the output of a CLI::fwrite() call.

How to Use 

CLI::setInputOutput() can set the MockInputOutput instance to the CLI class.
CLI::resetInputOutput() resets the InputOutput instance in the CLI class.
MockInputOutput::setInputs() sets the user input array.
MockInputOutput::getOutput() gets the command output.

The following test code is to test the command spark db:table:

<?php

use CodeIgniter\CLI\CLI;
use CodeIgniter\Test\CIUnitTestCase;
use CodeIgniter\Test\DatabaseTestTrait;
use CodeIgniter\Test\Mock\MockInputOutput;

final class DbTableTest extends CIUnitTestCase
{
    use DatabaseTestTrait;

    protected $migrateOnce = true;

    public function testDbTable(): void
    {
        // Set MockInputOutput to CLI.
        $io = new MockInputOutput();
        CLI::setInputOutput($io);

        // User will input "a" (invalid value) and "0".
        $io->setInputs(['a', '0']);

        command('db:table');

        // Get the whole output string.
        $output = $io->getOutput();

        $expected = 'Which table do you want to see? [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]: a';
        $this->assertStringContainsString($expected, $output);

        $expected = 'Data of Table "db_migrations":';
        $this->assertStringContainsString($expected, $output);

        // Remove MockInputOutput.
        CLI::resetInputOutput();
    }
}

Without MockInputOutput 

Testing CLI Output 

StreamFilterTrait 

New in version 4.3.0.

StreamFilterTrait provides an alternate to these helper methods.

You may need to test things that are difficult to test. Sometimes, capturing a stream, like PHP’s own STDOUT, or STDERR, might be helpful. The StreamFilterTrait helps you capture the output from the stream of your choice.

How to Use

StreamFilterTrait::getStreamFilterBuffer() gets the captured data from the buffer.
StreamFilterTrait::resetStreamFilterBuffer() resets captured data.

An example demonstrating this inside one of your test cases:

<?php

namespace Tests;

use CodeIgniter\CLI\CLI;
use CodeIgniter\Test\CIUnitTestCase;
use CodeIgniter\Test\StreamFilterTrait;

final class SomeTest extends CIUnitTestCase
{
    use StreamFilterTrait;

    public function testSomeOutput(): void
    {
        CLI::write('first.');

        $this->assertSame("\nfirst.\n", $this->getStreamFilterBuffer());

        $this->resetStreamFilterBuffer();

        CLI::write('second.');

        $this->assertSame("second.\n", $this->getStreamFilterBuffer());
    }
}

The StreamFilterTrait has a configurator that is called automatically. See Testing Traits.

If you override the setUp() or tearDown() methods in your test, then you must call the parent::setUp() and parent::tearDown() methods respectively to configure the StreamFilterTrait.

CITestStreamFilter 

CITestStreamFilter for manual/single use.

If you need to capture streams in only one test, then instead of using the StreamFilterTrait trait, you can manually add a filter to streams.

How to Use

CITestStreamFilter::registration() Filter registration.
CITestStreamFilter::addOutputFilter() Adding a filter to the output stream.
CITestStreamFilter::addErrorFilter() Adding a filter to the error stream.
CITestStreamFilter::removeOutputFilter() Removing a filter from the output stream.
CITestStreamFilter::removeErrorFilter() Removing a filter from the error stream.

<?php

namespace Tests;

use CodeIgniter\CLI\CLI;
use CodeIgniter\Test\CIUnitTestCase;
use CodeIgniter\Test\Filters\CITestStreamFilter;

final class SomeTest extends CIUnitTestCase
{
    public function testSomeOutput(): void
    {
        CITestStreamFilter::registration();
        CITestStreamFilter::addOutputFilter();

        CLI::write('first.');

        CITestStreamFilter::removeOutputFilter();
    }
}

Testing CLI Input 

PhpStreamWrapper 

New in version 4.3.0.

PhpStreamWrapper provides a way to write tests for methods that require user input, such as CLI::prompt(), CLI::wait(), and CLI::input().

Note

The PhpStreamWrapper is a stream wrapper class. If you don’t know PHP’s stream wrapper, see The streamWrapper class in the PHP maual.

How to Use

PhpStreamWrapper::register() Register the PhpStreamWrapper to the php protocol.
PhpStreamWrapper::restore() Restore the php protocol wrapper back to the PHP built-in wrapper.
PhpStreamWrapper::setContent() Set the input data.

Important

The PhpStreamWrapper is intended for only testing php://stdin. But when you register it, it handles all the php protocol streams, such as php://stdout, php://stderr, php://memory. So it is strongly recommended that PhpStreamWrapper be registered/unregistered only when needed. Otherwise, it will interfere with other built-in php streams while registered.

An example demonstrating this inside one of your test cases:

<?php

namespace Tests;

use CodeIgniter\CLI\CLI;
use CodeIgniter\Test\CIUnitTestCase;
use CodeIgniter\Test\PhpStreamWrapper;

final class SomeTest extends CIUnitTestCase
{
    public function testPrompt(): void
    {
        // Register the PhpStreamWrapper.
        PhpStreamWrapper::register();

        // Set the user input to 'red'. It will be provided as `php://stdin` output.
        $expected = 'red';
        PhpStreamWrapper::setContent($expected);

        $output = CLI::prompt('What is your favorite color?');

        $this->assertSame($expected, $output);

        // Restore php protocol wrapper.
        PhpStreamWrapper::restore();
    }
}