---
layout: doc
title: Asserts - Codeception - Documentation
---
# Asserts
### Installation
{% highlight yaml %}
composer require --dev codeception/module-asserts
{% endhighlight %}
### Description
Special module for using asserts in your tests.
### Actions
#### assertArrayHasKey
* `param int|string` $key
* `param array|\ArrayAccess` $array
* `param string` $message
Asserts that an array has a specified key.
#### assertArrayNotHasKey
* `param int|string` $key
* `param array|\ArrayAccess` $array
* `param string` $message
Asserts that an array does not have a specified key.
#### assertClassHasAttribute
* `param string` $attributeName
* `param string` $className
* `param string` $message
Asserts that a class has a specified attribute.
#### assertClassHasStaticAttribute
* `param string` $attributeName
* `param string` $className
* `param string` $message
Asserts that a class has a specified static attribute.
#### assertClassNotHasAttribute
* `param string` $attributeName
* `param string` $className
* `param string` $message
Asserts that a class does not have a specified attribute.
#### assertClassNotHasStaticAttribute
* `param string` $attributeName
* `param string` $className
* `param string` $message
Asserts that a class does not have a specified static attribute.
#### assertContains
* `param mixed` $needle
* `param iterable` $haystack
* `param string` $message
Asserts that a haystack contains a needle.
#### assertContainsEquals
* `param mixed` $needle
* `param iterable` $haystack
* `param string` $message
#### assertContainsOnly
* `param string` $type
* `param iterable` $haystack
* `param ?bool` $isNativeType
* `param string` $message
Asserts that a haystack contains only values of a given type.
#### assertContainsOnlyInstancesOf
* `param string` $className
* `param iterable` $haystack
* `param string` $message
Asserts that a haystack contains only instances of a given class name.
#### assertCount
* `param int` $expectedCount
* `param \Countable|iterable` $haystack
* `param string` $message
Asserts the number of elements of an array, Countable or Traversable.
#### assertDirectoryDoesNotExist
* `param string` $directory
* `param string` $message
Asserts that a directory does not exist.
#### assertDirectoryExists
* `param string` $directory
* `param string` $message
Asserts that a directory exists.
#### assertDirectoryIsNotReadable
* `param string` $directory
* `param string` $message
Asserts that a directory exists and is not readable.
#### assertDirectoryIsNotWritable
* `param string` $directory
* `param string` $message
Asserts that a directory exists and is not writable.
#### assertDirectoryIsReadable
* `param string` $directory
* `param string` $message
Asserts that a directory exists and is readable.
#### assertDirectoryIsWritable
* `param string` $directory
* `param string` $message
Asserts that a directory exists and is writable.
#### assertDoesNotMatchRegularExpression
* `param string` $pattern
* `param string` $string
* `param string` $message
Asserts that a string does not match a given regular expression.
#### assertEmpty
* `param mixed` $actual
* `param string` $message
Asserts that a variable is empty.
#### assertEquals
* `param mixed` $expected
* `param mixed` $actual
* `param string` $message
Asserts that two variables are equal.
#### assertEqualsCanonicalizing
* `param mixed` $expected
* `param mixed` $actual
* `param string` $message
Asserts that two variables are equal (canonicalizing).
#### assertEqualsIgnoringCase
* `param mixed` $expected
* `param mixed` $actual
* `param string` $message
Asserts that two variables are equal (ignoring case).
#### assertEqualsWithDelta
* `param mixed` $expected
* `param mixed` $actual
* `param float` $delta
* `param string` $message
Asserts that two variables are equal (with delta).
#### assertFalse
* `param mixed` $condition
* `param string` $message
Asserts that a condition is false.
#### assertFileDoesNotExist
* `param string` $filename
* `param string` $message
Asserts that a file does not exist.
#### assertFileEquals
* `param string` $expected
* `param string` $actual
* `param string` $message
Asserts that the contents of one file is equal to the contents of another file.
#### assertFileEqualsCanonicalizing
* `param string` $expected
* `param string` $actual
* `param string` $message
Asserts that the contents of one file is equal to the contents of another file (canonicalizing).
#### assertFileEqualsIgnoringCase
* `param string` $expected
* `param string` $actual
* `param string` $message
Asserts that the contents of one file is equal to the contents of another file (ignoring case).
#### assertFileExists
* `param string` $filename
* `param string` $message
Asserts that a file exists.
#### assertFileIsNotReadable
* `param string` $file
* `param string` $message
Asserts that a file exists and is not readable.
#### assertFileIsNotWritable
* `param string` $file
* `param string` $message
Asserts that a file exists and is not writable.
#### assertFileIsReadable
* `param string` $file
* `param string` $message
Asserts that a file exists and is readable.
#### assertFileIsWritable
* `param string` $file
* `param string` $message
Asserts that a file exists and is writable.
#### assertFileNotEquals
* `param string` $expected
* `param string` $actual
* `param string` $message
Asserts that the contents of one file is not equal to the contents of another file.
#### assertFileNotEqualsCanonicalizing
* `param string` $expected
* `param string` $actual
* `param string` $message
Asserts that the contents of one file is not equal to the contents of another file (canonicalizing).
#### assertFileNotEqualsIgnoringCase
* `param string` $expected
* `param string` $actual
* `param string` $message
Asserts that the contents of one file is not equal to the contents of another file (ignoring case).
#### assertFileNotExists
* `param string` $filename
* `param string` $message
Asserts that a file does not exist.
#### assertFinite
* `param mixed` $actual
* `param string` $message
Asserts that a variable is finite.
#### assertGreaterOrEquals
* `param mixed` $expected
* `param mixed` $actual
* `param string` $message
Asserts that a value is greater than or equal to another value.
#### assertGreaterThan
* `param mixed` $expected
* `param mixed` $actual
* `param string` $message
Asserts that a value is greater than another value.
#### assertGreaterThanOrEqual
* `param mixed` $expected
* `param mixed` $actual
* `param string` $message
Asserts that a value is greater than or equal to another value.
#### assertInfinite
* `param mixed` $actual
* `param string` $message
Asserts that a variable is infinite.
#### assertInstanceOf
* `param string` $expected
* `param mixed` $actual
* `param string` $message
Asserts that a variable is of a given type.
#### assertIsArray
* `param mixed` $actual
* `param string` $message
Asserts that a variable is of type array.
#### assertIsBool
* `param mixed` $actual
* `param string` $message
Asserts that a variable is of type bool.
#### assertIsCallable
* `param mixed` $actual
* `param string` $message
Asserts that a variable is of type callable.
#### assertIsClosedResource
* `param mixed` $actual
* `param string` $message
Asserts that a variable is of type resource and is closed.
#### assertIsEmpty
* `param mixed` $actual
* `param string` $message
Asserts that a variable is empty.
#### assertIsFloat
* `param mixed` $actual
* `param string` $message
Asserts that a variable is of type float.
#### assertIsInt
* `param mixed` $actual
* `param string` $message
Asserts that a variable is of type int.
#### assertIsIterable
* `param mixed` $actual
* `param string` $message
Asserts that a variable is of type iterable.
#### assertIsNotArray
* `param mixed` $actual
* `param string` $message
Asserts that a variable is not of type array.
#### assertIsNotBool
* `param mixed` $actual
* `param string` $message
Asserts that a variable is not of type bool.
#### assertIsNotCallable
* `param mixed` $actual
* `param string` $message
Asserts that a variable is not of type callable.
#### assertIsNotClosedResource
* `param mixed` $actual
* `param string` $message
Asserts that a variable is not of type resource.
#### assertIsNotFloat
* `param mixed` $actual
* `param string` $message
Asserts that a variable is not of type float.
#### assertIsNotInt
* `param mixed` $actual
* `param string` $message
Asserts that a variable is not of type int.
#### assertIsNotIterable
* `param mixed` $actual
* `param string` $message
Asserts that a variable is not of type iterable.
#### assertIsNotNumeric
* `param mixed` $actual
* `param string` $message
Asserts that a variable is not of type numeric.
#### assertIsNotObject
* `param mixed` $actual
* `param string` $message
Asserts that a variable is not of type object.
#### assertIsNotReadable
* `param string` $filename
* `param string` $message
Asserts that a file/dir exists and is not readable.
#### assertIsNotResource
* `param mixed` $actual
* `param string` $message
Asserts that a variable is not of type resource.
#### assertIsNotScalar
* `param mixed` $actual
* `param string` $message
Asserts that a variable is not of type scalar.
#### assertIsNotString
* `param mixed` $actual
* `param string` $message
Asserts that a variable is not of type string.
#### assertIsNotWritable
* `param string` $filename
* `param string` $message
Asserts that a file/dir exists and is not writable.
#### assertIsNumeric
* `param mixed` $actual
* `param string` $message
Asserts that a variable is of type numeric.
#### assertIsObject
* `param mixed` $actual
* `param string` $message
Asserts that a variable is of type object.
#### assertIsReadable
* `param string` $filename
* `param string` $message
Asserts that a file/dir is readable.
#### assertIsResource
* `param mixed` $actual
* `param string` $message
Asserts that a variable is of type resource.
#### assertIsScalar
* `param mixed` $actual
* `param string` $message
Asserts that a variable is of type scalar.
#### assertIsString
* `param mixed` $actual
* `param string` $message
Asserts that a variable is of type string.
#### assertIsWritable
* `param string` $filename
* `param string` $message
Asserts that a file/dir exists and is writable.
#### assertJson
* `param string` $actualJson
* `param string` $message
Asserts that a string is a valid JSON string.
#### assertJsonFileEqualsJsonFile
* `param string` $expectedFile
* `param string` $actualFile
* `param string` $message
Asserts that two JSON files are equal.
#### assertJsonFileNotEqualsJsonFile
* `param string` $expectedFile
* `param string` $actualFile
* `param string` $message
Asserts that two JSON files are not equal.
#### assertJsonStringEqualsJsonFile
* `param string` $expectedFile
* `param string` $actualJson
* `param string` $message
Asserts that the generated JSON encoded object and the content of the given file are equal.
#### assertJsonStringEqualsJsonString
* `param string` $expectedJson
* `param string` $actualJson
* `param string` $message
Asserts that two given JSON encoded objects or arrays are equal.
#### assertJsonStringNotEqualsJsonFile
* `param string` $expectedFile
* `param string` $actualJson
* `param string` $message
Asserts that the generated JSON encoded object and the content of the given file are not equal.
#### assertJsonStringNotEqualsJsonString
* `param string` $expectedJson
* `param string` $actualJson
* `param string` $message
Asserts that two given JSON encoded objects or arrays are not equal.
#### assertLessOrEquals
* `param mixed` $expected
* `param mixed` $actual
* `param string` $message
Asserts that a value is smaller than or equal to another value.
#### assertLessThan
* `param mixed` $expected
* `param mixed` $actual
* `param string` $message
Asserts that a value is smaller than another value.
#### assertLessThanOrEqual
* `param mixed` $expected
* `param mixed` $actual
* `param string` $message
Asserts that a value is smaller than or equal to another value.
#### assertMatchesRegularExpression
* `param string` $pattern
* `param string` $string
* `param string` $message
Asserts that a string matches a given regular expression.
#### assertNan
* `param mixed` $actual
* `param string` $message
Asserts that a variable is nan.
#### assertNotContains
* `param mixed` $needle
* `param iterable` $haystack
* `param string` $message
Asserts that a haystack does not contain a needle.
#### assertNotContainsEquals
* `param ` $needle
* `param iterable` $haystack
* `param string` $message
#### assertNotContainsOnly
* `param string` $type
* `param iterable` $haystack
* `param ?bool` $isNativeType
* `param string` $message
Asserts that a haystack does not contain only values of a given type.
#### assertNotCount
* `param int` $expectedCount
* `param \Countable|iterable` $haystack
* `param string` $message
Asserts the number of elements of an array, Countable or Traversable.
#### assertNotEmpty
* `param mixed` $actual
* `param string` $message
Asserts that a variable is not empty.
#### assertNotEquals
* `param mixed` $expected
* `param mixed` $actual
* `param string` $message
Asserts that two variables are not equal.
#### assertNotEqualsCanonicalizing
* `param mixed` $expected
* `param mixed` $actual
* `param string` $message
Asserts that two variables are not equal (canonicalizing).
#### assertNotEqualsIgnoringCase
* `param mixed` $expected
* `param mixed` $actual
* `param string` $message
Asserts that two variables are not equal (ignoring case).
#### assertNotEqualsWithDelta
* `param mixed` $expected
* `param mixed` $actual
* `param float` $delta
* `param string` $message
Asserts that two variables are not equal (with delta).
#### assertNotFalse
* `param mixed` $condition
* `param string` $message
Asserts that a condition is not false.
#### assertNotInstanceOf
* `param string` $expected
* `param mixed` $actual
* `param string` $message
Asserts that a variable is not of a given type.
#### assertNotNull
* `param mixed` $actual
* `param string` $message
Asserts that a variable is not null.
#### assertNotRegExp
* `param string` $pattern
* `param string` $string
* `param string` $message
Asserts that a string does not match a given regular expression.
#### assertNotSame
* `param mixed` $expected
* `param mixed` $actual
* `param string` $message
Asserts that two variables do not have the same type and value.
#### assertNotSameSize
* `param \Countable|iterable` $expected
* `param \Countable|iterable` $actual
* `param string` $message
Assert that the size of two arrays (or `Countable` or `Traversable` objects) is not the same.
#### assertNotTrue
* `param mixed` $condition
* `param string` $message
Asserts that a condition is not true.
#### assertNull
* `param mixed` $actual
* `param string` $message
Asserts that a variable is null.
#### assertObjectHasAttribute
* `param string` $attributeName
* `param object` $object
* `param string` $message
Asserts that an object has a specified attribute.
#### assertObjectNotHasAttribute
* `param string` $attributeName
* `param object` $object
* `param string` $message
Asserts that an object does not have a specified attribute.
#### assertRegExp
* `param string` $pattern
* `param string` $string
* `param string` $message
Asserts that a string matches a given regular expression.
#### assertSame
* `param mixed` $expected
* `param mixed` $actual
* `param string` $message
Asserts that two variables have the same type and value.
#### assertSameSize
* `param \Countable|iterable` $expected
* `param \Countable|iterable` $actual
* `param string` $message
Assert that the size of two arrays (or `Countable` or `Traversable` objects) is the same.
#### assertStringContainsString
* `param string` $needle
* `param string` $haystack
* `param string` $message
#### assertStringContainsStringIgnoringCase
* `param string` $needle
* `param string` $haystack
* `param string` $message
#### assertStringEndsNotWith
* `param string` $suffix
* `param string` $string
* `param string` $message
Asserts that a string ends not with a given suffix.
#### assertStringEndsWith
* `param string` $suffix
* `param string` $string
* `param string` $message
Asserts that a string ends with a given suffix.
#### assertStringEqualsFile
* `param string` $expectedFile
* `param string` $actualString
* `param string` $message
Asserts that the contents of a string is equal to the contents of a file.
#### assertStringEqualsFileCanonicalizing
* `param string` $expectedFile
* `param string` $actualString
* `param string` $message
Asserts that the contents of a string is equal to the contents of a file (canonicalizing).
#### assertStringEqualsFileIgnoringCase
* `param string` $expectedFile
* `param string` $actualString
* `param string` $message
Asserts that the contents of a string is equal to the contents of a file (ignoring case).
#### assertStringMatchesFormat
* `param string` $format
* `param string` $string
* `param string` $message
Asserts that a string matches a given format string.
#### assertStringMatchesFormatFile
* `param string` $formatFile
* `param string` $string
* `param string` $message
Asserts that a string matches a given format file.
#### assertStringNotContainsString
* `param string` $needle
* `param string` $haystack
* `param string` $message
#### assertStringNotContainsStringIgnoringCase
* `param string` $needle
* `param string` $haystack
* `param string` $message
#### assertStringNotEqualsFile
* `param string` $expectedFile
* `param string` $actualString
* `param string` $message
Asserts that the contents of a string is not equal to the contents of a file.
#### assertStringNotEqualsFileCanonicalizing
* `param string` $expectedFile
* `param string` $actualString
* `param string` $message
Asserts that the contents of a string is not equal to the contents of a file (canonicalizing).
#### assertStringNotEqualsFileIgnoringCase
* `param string` $expectedFile
* `param string` $actualString
* `param string` $message
Asserts that the contents of a string is not equal to the contents of a file (ignoring case).
#### assertStringNotMatchesFormat
* `param string` $format
* `param string` $string
* `param string` $message
Asserts that a string does not match a given format string.
#### assertStringNotMatchesFormatFile
* `param string` $formatFile
* `param string` $string
* `param string` $message
Asserts that a string does not match a given format string.
#### assertStringStartsNotWith
* `param string` $prefix
* `param string` $string
* `param string` $message
Asserts that a string starts not with a given prefix.
#### assertStringStartsWith
* `param string` $prefix
* `param string` $string
* `param string` $message
Asserts that a string starts with a given prefix.
#### assertThat
* `param mixed` $value
* `param \PHPUnit\Framework\Constraint\Constraint` $constraint
* `param string` $message
Evaluates a PHPUnit\Framework\Constraint matcher object.
#### assertThatItsNot
* `param mixed` $value
* `param \PHPUnit\Framework\Constraint\Constraint` $constraint
* `param string` $message
Evaluates a PHPUnit\Framework\Constraint matcher object.
#### assertTrue
* `param mixed` $condition
* `param string` $message
Asserts that a condition is true.
#### assertXmlFileEqualsXmlFile
* `param string` $expectedFile
* `param string` $actualFile
* `param string` $message
Asserts that two XML files are equal.
#### assertXmlFileNotEqualsXmlFile
* `param string` $expectedFile
* `param string` $actualFile
* `param string` $message
Asserts that two XML files are not equal.
#### assertXmlStringEqualsXmlFile
* `param string` $expectedFile
* `param \DOMDocument|string` $actualXml
* `param string` $message
Asserts that two XML documents are equal.
#### assertXmlStringEqualsXmlString
* `param \DOMDocument|string` $expectedXml
* `param \DOMDocument|string` $actualXml
* `param string` $message
Asserts that two XML documents are equal.
#### assertXmlStringNotEqualsXmlFile
* `param string` $expectedFile
* `param \DOMDocument|string` $actualXml
* `param string` $message
Asserts that two XML documents are not equal.
#### assertXmlStringNotEqualsXmlString
* `param \DOMDocument|string` $expectedXml
* `param \DOMDocument|string` $actualXml
* `param string` $message
Asserts that two XML documents are not equal.
#### expectThrowable
* `param \Throwable|string` $throwable
* `param callable` $callback
* `return void`
Handles and checks throwables (Exceptions/Errors) called inside the callback function.
Either throwable class name or throwable instance should be provided.
{% highlight php %}
expectThrowable(MyThrowable::class, function() {
$this->doSomethingBad();
});
$I->expectThrowable(new MyException(), function() {
$this->doSomethingBad();
});
{% endhighlight %}
If you want to check message or throwable code, you can pass them with throwable instance:
{% highlight php %}
expectThrowable(new MyError("Don't do bad things"), function() {
$this->doSomethingBad();
});
{% endhighlight %}
#### fail
* `param string` $message
Fails a test with the given message.
#### markTestIncomplete
* `param string` $message
Mark the test as incomplete.
#### markTestSkipped
* `param string` $message
Mark the test as skipped.