[Console] Allow to test the different streams at the same time #61494

theofidry · 2025-08-21T18:55:36Z

Q	A
Branch?	7.4
Bug fix?	no
New feature?	yes
Deprecations?	yes
Issues	Fix #...
License	MIT

Currently testing a command looks like this:

// tests/Command/CreateUserCommandTest.php
namespace App\Tests\Command;

use Symfony\Bundle\FrameworkBundle\Console\Application;
use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
use Symfony\Component\Console\Tester\CommandTester;

class CreateUserCommandTest extends KernelTestCase
{
    private CommandTester $commandTester;

    protected function setup(): void
    {
        self::bootKernel();

        $application = new Application(self::$kernel);

        $command = $application->find('app:create-user');
        $this->commandTester = new CommandTester($command);
    }

    public function testExecute(): void
    {
        $this->commandTester->execute(['username' => 'Wouter']);

        $commandTester->assertCommandIsSuccessful();

        $output = $commandTester->getDisplay();
        $this->assertStringContainsString('Username: Wouter', $output);
    }
}

However, sometimes it is important to test not just the combined output of the
command, but the stdout and stderr streams separately. One can do so using the
capture_stderr_separately option:

// tests/Command/CreateUserCommandTest.php
namespace App\Tests\Command;

use Symfony\Bundle\FrameworkBundle\Console\Application;
use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
use Symfony\Component\Console\Tester\CommandTester;

class CreateUserCommandTest extends KernelTestCase
{
    private CommandTester $commandTester;

    protected function setup(): void
    {
        self::bootKernel();

        $application = new Application(self::$kernel);

        $command = $application->find('app:create-user');
        $this->commandTester = new CommandTester($command);
    }

    public function testExecute(): void
    {
        $this->commandTester->execute(
            ['username' => 'Wouter'],
            ['capture_stderr_separately' => true],
        );

        $commandTester->assertCommandIsSuccessful();

        $stdoutOutput = $commandTester->getDisplay();
        $stderrOutput = $commandTester->getErrorOutput();
    }
}

It works well. However, you know are testing two separate outputs. If the output
is important to you and you want to make sure things are displayed correctly to
the user, not just in each individual streams, you need to have both tests.

It is unnecessarily tedious. Instead, this PR proposes to expose and output that
offers both options at the same time.

// tests/Command/CreateUserCommandTest.php
namespace App\Tests\Command;

use Symfony\Bundle\FrameworkBundle\Console\Application;
use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
use Symfony\Component\Console\Tester\CommandTester;

class CreateUserCommandTest extends KernelTestCase
{
    private CommandTester $commandTester;

    protected function setup(): void
    {
        self::bootKernel();

        $application = new Application(self::$kernel);

        $command = $application->find('app:create-user');
        $this->commandTester = new CommandTester($command);
    }

    public function testExecute(): void
    {
        $result = $this->commandTester->run(
            ['username' => 'Wouter'],
        );

        $result->assertIsSuccessful();

        $combinedOutput = $result->getDisplay();

        $stdoutOutput = $result->getOutput();
        $stderrOutput = $result->getErrorOutput();
    }
}

This is the general spirit of this MR. Unfortunately I'm easily distracted, so I picked up a few things on the way which make sense as a whole but maybe should be left out for now.

Review the general direction
Update the changelog
Update the upgrade

on execute($options) # Conflicts: # src/Symfony/Component/Console/Tester/CommandTester.php

theofidry · 2025-08-21T19:01:48Z

src/Symfony/Component/Console/Output/StreamOutput.php

@@ -74,6 +76,7 @@ protected function doWrite(string $message, bool $newline): void
        fflush($this->stream);
    }

+    // TODO: should be public & static?
    /**


this piece of code is implemented and use in several places. I wonder if it would make sense to either expose it as a static public utility or extract it and re-use that extracted utility here.

But irrelevant to the MR, to clean up

theofidry · 2025-08-21T19:04:42Z

src/Symfony/Component/Console/Tester/CommandTester.php

    public function __construct(
-        callable|Command $command,
+        callable|Command          $command,
+        // TODO: to discuss if we want it in the constructor with the setters or only in the ::run() method


open question

theofidry · 2025-08-21T19:04:52Z

src/Symfony/Component/Console/Tester/CommandTester.php

+        ];
+    }
+
+    // TODO: to discuss if we want fluent setters


open question (note that if we have them in the constructor instead, we do not need those setters).

In general I am not a fan of fluent setters, but in the context of such test utilities it does make it a bit nicer. It's very subjective though

theofidry · 2025-08-21T19:06:47Z

src/Symfony/Component/Console/Tester/CommandTester.php

@@ -49,29 +123,90 @@ public function __construct(
     */
    public function execute(array $input, array $options = []): int


to deprecate in favour of the ::run() IMO

theofidry · 2025-08-21T19:10:32Z

src/Symfony/Component/Console/Tester/ConsoleAssertionsTrait.php

+    }
+
+    // TODO: here we need to pass the result first if we want to keep some arguments optional.
+    //   Not wanting this is an argument for having the assertions in the ExecutionResult instead.


If we want to keep the approach of having traits in the test cases, then I think this trait makes sense. Otherwise it would make more sense to have this as part of ExecutionResult IMO

theofidry · 2025-08-21T19:12:05Z

src/Symfony/Component/Console/Tester/OutputNormalizers.php

+/**
+ * Collection of output normalizers
+ */
+final class OutputNormalizers


strictly speaking not needed for the purpose of the MR so could be scrapped. I otherwise thought it would be interesting to have a dedicated re-usable utility rather than private methods left and right.

theofidry · 2025-08-21T19:15:46Z

The application tester should also be adapted

theofidry added 6 commits August 20, 2025 16:27

feat: Add parameters to the command tester class to avoid having to rely

ccb38e8

on execute($options) # Conflicts: # src/Symfony/Component/Console/Tester/CommandTester.php

add run with execution result output

629c58a

refactor: extract code for the creation of the input

24ae826

combine outputs

c87d6b0

add combined output

6468952

fix cs

78ae091

theofidry requested a review from chalasr as a code owner August 21, 2025 18:55

carsonbot added Status: Needs Review Deprecation Feature labels Aug 21, 2025

carsonbot added this to the 7.4 milestone Aug 21, 2025

carsonbot changed the title ~~Feat/test combined output~~ Feat/test combined output Aug 21, 2025

minor cleanups

a455715

theofidry commented Aug 21, 2025

View reviewed changes

theofidry changed the title ~~Feat/test combined output~~ [Console] Allow to test the different streams at the same time Aug 21, 2025

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Uh oh!

[Console] Allow to test the different streams at the same time #61494

[Console] Allow to test the different streams at the same time #61494

theofidry commented Aug 21, 2025 •

edited

Loading

Uh oh!

theofidry Aug 21, 2025

Uh oh!

theofidry Aug 21, 2025

Uh oh!

theofidry Aug 21, 2025

Uh oh!

theofidry Aug 21, 2025

Uh oh!

theofidry Aug 21, 2025

Uh oh!

theofidry Aug 21, 2025

Uh oh!

theofidry commented Aug 21, 2025

Uh oh!

Uh oh!

		@@ -49,29 +123,90 @@ public function __construct(
		*/
		public function execute(array $input, array $options = []): int

Uh oh!

[Console] Allow to test the different streams at the same time #61494

Are you sure you want to change the base?

[Console] Allow to test the different streams at the same time #61494

Conversation

theofidry commented Aug 21, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

theofidry Aug 21, 2025

Choose a reason for hiding this comment

Uh oh!

theofidry Aug 21, 2025

Choose a reason for hiding this comment

Uh oh!

theofidry Aug 21, 2025

Choose a reason for hiding this comment

Uh oh!

theofidry Aug 21, 2025

Choose a reason for hiding this comment

Uh oh!

theofidry Aug 21, 2025

Choose a reason for hiding this comment

Uh oh!

theofidry Aug 21, 2025

Choose a reason for hiding this comment

Uh oh!

theofidry commented Aug 21, 2025

Uh oh!

Uh oh!

theofidry commented Aug 21, 2025 •

edited

Loading