Unit testing a function with a timestamp - php

Question

I have an object function to send news to an API:
class Manager
{
public function __construct(GuzzleHttp\Client $client)
{
$this->client = $client;
}
public function uploadNews($title, $text, $timestamp = null)
{
// DEFAULT FOR PUBLISH TIMESTAMP IS SET IF VALUE IS NULL
$timestamp = $timestamp ?? time();
$requestBody = [
'header' => [
'Accept' => 'application/json',
],
'timeout' => 300,
'body' => [
'title' => $title,
'text' => $text,
'publish_date' => $timestamp,
]
];
return $this->client->request('POST', 'http://api/endpoint', $requestBody);
}
}
How do I write a PHPUnit unit test to test the final $request passed to the client's request() function is of the expected format, when the $timestamp is not set (the API expects a timestamp)? I've written a unit test. But is not ideal, since there could be a difference in the tow timestamps.
class ManagerTest extends \PHPUnit\Framework\TestCase
{
public function testCanUploadNewsWithoutTimestamp()
{
$expectedRequestBody = [
'header' => [
'Accept' => 'application/json',
],
'timeout' => 300,
'body' => [
'title' => 'News title',
'text' => 'News article sample text.',
'publish_date' => time(),
]
];
$guzzleMock = $this->createMock(GuzzleHttp\Client::class);
$guzzleMock->expects($this->once())
->method('request')
->with(
'POST',
'http://api/endpoint',
$expectedRequestBody
);
(new Manager($guzzleMock))->uploadNews(
'News title',
'News article sample text.'
);
}
}
This is my current test result:
Parameter 2 for invocation GuzzleHttp\Client::request('POST', 'http://api/endpoint', Array (...)) does not match expected value.
Failed asserting that two arrays are equal.
--- Expected
+++ Actual
## ##
'body' => Array (
'title' => 'News title'
'text' => 'News article sample text.'
- 'publish_date' => 1574550178
+ 'publish_date' => 1574550179
)
)
Please note that the only thing I need to make sure is that the timestamp is passed with request. The value of the timestamp doesn't matter.
PS: I'm really new to Test Driven Development, so the answer might be obvious and I might still not know it.