6. Syntaxes

6.1. What is a Syntax?

A syntax explains how an assertion gets translated for a matcher. A simple example is:

? equals ?

Which can be used in your test:


So the syntax ? equals ? matches with two data items; 123 and 456.

Syntaxes can contain multiple words in a row:

? is greater than ?

Which can be used the same way as:


Syntaxes can contain as many data points as you need:

? is within ? of ?

And finally the syntax can start with a data element or not:

date ? is after ?

6.2. Restricting Data Types

In a lot of cases it only makes sense for an assertion to work with known data types, for example:

? starts with ?

Here we are talking about strings. If someone were to put through a type that doesn’t make sense or cannot be computed like:

$this->assert(new stdClass())->startsWith(true);

We would no doubt get some error, or at the very least the assertion would return an unreliable result.

There are two ways to mitigate this:

  1. Do the type checking yourself in the matcher class by checking each data element for a sane type.

  2. Use the syntax to specify the allowed types. This is must easer:

    ?:string starts with ?:string

Now concise will do the type checking for us. If we get some bad types it will throw an exception explaining the error and never need to the call the actual matcher. It also means that your matcher class can guarantee that the data elements taken in are both strings.

More complex requirements can be specified by separating with a comma:

?:int,float is greater than ?:int,float

Or, the reverse logic can be used to blacklist types (instead of whitelist) them:

?:!object is scalar

Will accept any type that is not an object.

6.3. Special Data Types

Due to PHP’s relaxed typing we want to be sure we don’t potentially run into this problem:


This will fail because '123' is a string, but it can also be treated as a number. So concise provides some special types that do value checking as well:

?:number is greater than ?:number

We can now safely use number-like values:

$this->assert('123')->isGreaterThan(1.23); // numbers
$this->assert('foo')->isGreaterThan(1.23); // 'foo' is not a number

See the table below for all the supported types:

Type Example values
int 123
float 1.23
string "abc"
array array()
resource fopen('.', 'r')
object new \stdClass()
callable function () { }
regex "/foo/"
class "Concise\Core\TestCase"
number 123, 1.23, "12.3"
bool true

Separately from the type names in the table you may also specify specific classes:

?:DateTime is a date
?:\DateTime is a date

Subclasses are allowed.