JSON Test Assertions & Seeding the Database
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Login SubscribeLet's make this test real with data and assertions.
There are two main ways to do assertions with Browser. First, it comes with a bunch of built-in methods to help, like ->assertJson()
. Or... you can always just grab the JSON that comes back from an endpoint and check things using the built-in PHPUnit assertions you know and love. We'll see both.
Let's start by checking ->assertJson()
:
// ... lines 1 - 8 | |
class DragonTreasureResourceTest extends KernelTestCase | |
{ | |
// ... lines 11 - 13 | |
public function testGetCollectionOfTreasures(): void | |
{ | |
$this->browser() | |
->get('/api/treasures') | |
// ... line 18 | |
->assertJson() | |
; | |
} | |
} |
When we run that:
symfony php bin/phpunit
It passes! Cool! We know that this response should have a hydra:totalItems
property set to the number of results. Right now, our database is empty... but we can at least assert that it matches zero.
To do that, use ->assertJsonMatches()
.
This is a special method from Browser that uses a special syntax that allows us to read different parts off the JSON. We'll dig into it in a minute.
But this one is simple: assert that hydra:totalItems
equals 0
:
// ... lines 1 - 8 | |
class DragonTreasureResourceTest extends KernelTestCase | |
{ | |
// ... lines 11 - 13 | |
public function testGetCollectionOfTreasures(): void | |
{ | |
$this->browser() | |
// ... lines 17 - 18 | |
->assertJson() | |
->assertJsonMatches('hydra:totalItems', 0) | |
; | |
} | |
} |
When we try this:
symfony php bin/phpunit
It fails! But with a great error:
mtdowling/jmespath.php
is required to search JSON
Hello JMESPath
Ah, we need to install that! Copy the composer require
line, find your terminal, and run it:
composer require mtdowling/jmespath.php --dev
This "JMESPath" thing is actually super cool: it's a "query language" for reading different parts of any JSON. For example, if this is your JSON and you want to read the a
key, just say a
. Simple.
But you can also do deeper, like: a.b.c.d
. Or, get crazier: grab the 1
index, or grab a.b.c
, then the 0
index, .d
, the 1
index then the 0
index. You can even slice the array in different ways. Basically... you can go nuts.
But we're not going to lose our minds with this. It's a handy syntax... but if things get too complex, we can always test the JSON manually, which we'll do in a bit.
Anyway, now that we have the library installed, let's run the test again.
symfony php bin/phpunit
It still fails! With a weird error:
Syntax error at character 5
hydra:totalItems
.
Unfortunately, the :
is a special character inside of JMESPath. So whenever we have a :
, we need to put quotes around that key:
// ... lines 1 - 8 | |
class DragonTreasureResourceTest extends KernelTestCase | |
{ | |
// ... lines 11 - 13 | |
public function testGetCollectionOfTreasures(): void | |
{ | |
$this->browser() | |
// ... lines 17 - 19 | |
->assertJsonMatches('"hydra:totalItems"', 0) | |
; | |
} | |
} |
Not ideal, but not a huge inconvenience.
Now when we try it:
symfony php bin/phpunit
It passes!
Seeding the Database
But... this isn't a very interesting test: we're just asserting that we get nothing back... because the database is empty. To make our test real, we need data: we need to seed the database with data at the start of the test.
Tip
To use Foundry factories in a test, also add a use Factories;
trait to the top of your test class.
Things worked without that in this case, but in the future, you'll likely get an error.
Fortunately, Foundry makes that dead-simple. At the top, call DragonTreasureFactory::createMany()
and let's create 5 treasures. Now, below, assert that we get 5 results:
// ... lines 1 - 4 | |
use App\Factory\DragonTreasureFactory; | |
// ... lines 6 - 9 | |
class DragonTreasureResourceTest extends KernelTestCase | |
{ | |
// ... lines 12 - 14 | |
public function testGetCollectionOfTreasures(): void | |
{ | |
DragonTreasureFactory::createMany(5); | |
$this->browser() | |
// ... lines 20 - 22 | |
->assertJsonMatches('"hydra:totalItems"', 5) | |
// ... line 24 | |
; | |
} | |
} |
It's just that simple. And actually, let me put our dump back so we can see the result:
// ... lines 1 - 9 | |
class DragonTreasureResourceTest extends KernelTestCase | |
{ | |
// ... lines 12 - 14 | |
public function testGetCollectionOfTreasures(): void | |
{ | |
// ... lines 17 - 18 | |
$this->browser() | |
// ... line 20 | |
->dump() | |
// ... line 22 | |
->assertJsonMatches('"hydra:totalItems"', 5) | |
// ... line 24 | |
; | |
} | |
} |
Try it now:
symfony php bin/phpunit
It passes! And if you look up, yea! The response has 5 treasures! Dang, that was easy.
Next: let's use JMESPath to assert something more challenging. Then we'll back up and see how we can dig into Browser to give us infinite flexibility - and simplicity - when it comes to testing JSON.
Hi everyone !
For me, this, it is not working :
I've got this error :
PDOException: SQLSTATE[23000]: Integrity constraint violation: 19 NOT NULL constraint failed: dragon_treasure.owner_id
So, let's do it :
Voilà : It's alive :-)
OK (1 test, 3 assertions)
I'm using SQLite, I don't know if it matters.