Cara menggunakan phpunit assert string length

PHPUnit has been blowing away its competition for more than 5 years now. With the use of the right PHPUnit assertions, you can get the most benefit out of PHPUnit. In this post, we will look into some popular and very useful PHPUnit assertions you should be using day to day in your PHPUnit tests. Let’s get cracking!

Table of contents

PHPUnit Assertions to know about

Currently, PHPUnit is at version 9.5. As per the latest docs there are 60 assert methods you can use in your PHPUnit tests.

These PHPUnit assertions range from checking if to the ever-popular to the not so widely used PHPUnit assertion.

Analyzing PHPUnit Assertions usage in a small, medium, and large project

To know which PHPUnit assertions are used most in the projects I have worked with in the past years I ran the following command:

grep -rin ">assert" . | awk '{print $2}' | awk -F"[>(]" '{print $2}' | sort | uniq -c | sort -nr

The above command should be run in your tests folder. It basically looks for >assert* in the code and sorts them, then counts the unique occurrences and again sorts at the end with most occurrences first.

I will be taking three projects, one small, the second one medium, and the third one is a large one. The size is not only the code but also the number of tests and assertions in the projects.

These projects are built with Symfony and another framework. Two of them are REST APIs and one of them which is the big one has a user interface too.

Small Project with PHPUnit Assertions

The small project built with Symfony as a REST API has only 104 tests and 306 PHPUnit assertions. The above command when executed on this project’s tests folder gave the following output:

As we can see, the most popular PHPUnit assertion used in this project is

$this->assertEquals('1', '0', 'check if 1 is 1');

0 which is used 73 times.

After that,

$this->assertEquals('1', '0', 'check if 1 is 1');

$this->assertEquals('1', '0', 'check if 1 is 1');

Medium project for PHPUnit Assertions count

The medium project built with Symfony which is a REST API has 221 tests and 472 PHPUnit assertions. The above command when run on its tests directory looks like below:

We can clearly see that

$this->assertEquals('1', '0', 'check if 1 is 1');

1 and

$this->assertEquals('1', '0', 'check if 1 is 1');

0 is used the most in this small project with 37 times each.

The numbers of asserts don’t add up to 221 because there are a lot of PHPunit data providers used in these tests.

Still,

$this->assertEquals('1', '0', 'check if 1 is 1');

$this->assertEquals('1', '0', 'check if 1 is 1');

Big project for counting PHPUnit Assertions

Next up is the big-sized project, it has both APIs and user interface. It has unit tests as well as some integration tests. This project has a whopping 5824 tests and 13975 PHPUnit assertions. When we run the above PHPUnit assertions counter command on this project’s tests folder it yields:

Even here,

$this->assertEquals('1', '0', 'check if 1 is 1');

0 is still the most used PHPUnit assertion with 3145 occurrences.

That accounts for 22.5% of all asserts in the test suite. Next in line is

$this->assertEquals('1', '0', 'check if 1 is 1');

Anatomy of PHPUnit assertions

Assertions in PHPUnit follow a pattern, for instance,

$this->assertEquals('1', '0', 'check if 1 is 1');

There was 1 failure:

1)FCQN::testAssertEqualsFail
check if 1 is 1
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'1'
+'0'

There was 1 failure:

1)FCQN::testAssertEqualsFail
check if 1 is 1
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'1'
+'0'

There was 1 failure:

1)FCQN::testAssertEqualsFail
check if 1 is 1
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'1'
+'0'

The message is printed when the test fails.

For instance the following test:

$this->assertEquals('1', '0', 'check if 1 is 1');

Will result in:

There was 1 failure:

1)FCQN::testAssertEqualsFail
check if 1 is 1
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'1'
+'0'

Notice the

There was 1 failure:

1)FCQN::testAssertEqualsFail
check if 1 is 1
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'1'
+'0'

Some PHPUnit assertions you must start using today

In the past, I have used many PHPUnit assertions among the 60 odd available ones. Below are some of them which have been particularly useful:

assertJsonStringEqualsJsonString

This PHPUnit assertion is very handy when testing APIs’ responses. You can use this

There was 1 failure:

1)FCQN::testAssertEqualsFail
check if 1 is 1
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'1'
+'0'

$this->assertJsonStringEqualsJsonString(
    '{"message": "ok"}', 
    json_encode(["message" => "ok"]), 
    'Check message ok json'
);

The next one is about Regex matching.

assertMatchesRegularExpression or assertRegExp

As the name sounds the assert will match for the regular expression. I have found it helpful to test error messages that begin with something or have a defined pattern. It was called

There was 1 failure:

1)FCQN::testAssertEqualsFail
check if 1 is 1
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'1'
+'0'

There was 1 failure:

1)FCQN::testAssertEqualsFail
check if 1 is 1
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'1'
+'0'

There was 1 failure:

1)FCQN::testAssertEqualsFail
check if 1 is 1
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'1'
+'0'

$this->assertRegExp(
    '/Exception 40\d/', 
    'Exception 501', 
    'Check if it is exception 40x'
);

The next one is about strings.

assertStringContainsString

This is also a very handy assertion to check if a given string has another string. If you want to ignore the letter case you can use

There was 1 failure:

1)FCQN::testAssertEqualsFail
check if 1 is 1
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'1'
+'0'

There was 1 failure:

1)FCQN::testAssertEqualsFail
check if 1 is 1
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'1'
+'0'

$this->assertJsonStringEqualsJsonString(
    '{"message": "ok"}', 
    json_encode(["message" => "ok"]), 
    'Check message ok json'
);

$this->assertStringContainsString(
    'Error', 
    'Error id is required, the quote is required', 
    'Check if word Error is present'
);

Consequently, we have the ever-popular assert Equals PHPUnit assertion with a twist.

assetEqualsWithDelta

Another useful PHPUnit assertion is

$this->assertJsonStringEqualsJsonString(
    '{"message": "ok"}', 
    json_encode(["message" => "ok"]), 
    'Check message ok json'
);

$this->assertEqualsWithDelta(34.3, 34.1, 0.5, '0.5 degree variance in temperature is allowed');

Subsequently, we have a PHPUnit assertion that is related to PHP arrays.

assertArrayHasKey

The

$this->assertJsonStringEqualsJsonString(
    '{"message": "ok"}', 
    json_encode(["message" => "ok"]), 
    'Check message ok json'
);

public function testAssertArrayHasKey()
{
    $exchangeRates = ['usd' => 0.77, 'euro' => 0.63];

    $this->assertArrayHasKey('usd', $exchangeRates, 'Check if USD is available');
    $this->assertEquals(0.77, $exchangeRates['usd'], 'Test if USD rate is 0.77');
}

You can view all the 5 PHPUnit assertions’ examples in this gist.

Conclusion

You can find a list of PHPUnit assertions in this list too.

Before wiring up 2 or 3 PHPUnit assertions please do check on the docs if there is any existing assertion that suits your use case.