Data Providers get executed before setupBeforeClass

[vicb]

The data providers get called before the static setupBeforeClass has been executed. If think it should be the other way around.

Use case:

• We have a list of adapters. Some adapters are only supported on some environment (ie Linux vs Win),
• I would like to initialize a list of supported adapters once and pass it to all the tests through a data provider,
• The cleanest way I can imagine is to initialize a static property in setupBeforeClass and have the provider returns that property

The problem is that the property is not initialized when the provider gets called.

Version found: 3.7.14

[whatthejeff]

I'm not sure that enforcing some order so that static resources can be initialized in setupBeforeClass really makes sense if you consider that data providers aren't required to be static or even in the same test class.

Why not just lazy initialize the adapters? Then the order doesn't matter at all.

[sebastianbergmann]

Without running the data provider we do not know how many tests a test method runs. In a perfect world we would break B/C and require data providers to be objects that implement an interface that extends Countable. That way we could separate these concerns and have a much cleaner situation.

[vicb]

@whatthejeff This is what we end up doing. However initializing in the constructor could be a little bit cleaner, because parameters have to be wrapped in an array when returned from a provider.

@sebastianbergmann ok I understand why they are called before now, what about mentionning it in the doc ? (I can open a PR which the changes if you are ok). I am not even sure having objects would help a lot: if you look at my ex, there is a dependency from one provider to the other.

Thanks for your replies, closing the issue.

[whatthejeff]

@vicb, I'll gladly merge a documentation-related PR for this.

[srosato]

I might be a bit late to the scene, but what I happen to do when I have dependencies that I need to initialize is to ditch the @dataProvider annotation and use yield instead.

[rquadling]

@srosato I'm being dumb (I've not used yield). Could you give a brief example of how to do this please? Via https://gist.github.com if an example here is not appropriate.

[shawnpyle]

If your @dataProvider requires setup code and they aren't terribly large, you can specify them as strings and eval them in the test. For example:

public function myProvider() {
    return [
        'new Klass("param 1", "param 2")',
        'new Klass("param 1", "param 2")',
    ];
}

/**
 * @dataProvider myProvider
 */
public testMyFunction($instance_str) {
    $klass = eval("return {$instance_str};");
    # continue testing $klass ...
}

[sweiguny]

my two cents:

Instead of a dataprovider relying on a static property (which we know isn't possible) I am setting the needed data/objects as class member(s) of the test class in setUp() method.
in tearDown() i set it/them to null, or when there are complex objects I implement a clear() method for it.

as long as there aren't too many test-class-wide dependencies, i feel comfortable with this approach.
but when there are more than one or two such dependencies, you might need to overthink your overall design.

specifically, i use a DB connection as static property which is set in setUpBeforeClass() and set $queryBuilder, which gets the connection injected, as a class-member in setUp() (instead of returning it in a dataprovider).

[machitgarha]

A solution would be defining a new private method and define as many variables as needed, as static ones inside it. Then, check if one of them is set, and if it is not, set all of them and return (or yield) them. This way, the variables will be declared only once, even if you have ten providers or whatever. Besides, you can use it in setUpBeforeClass() or setUp().

See it in an example:

private static function getData()
{
    static $data, $anotherData;

    if (!isset($data)) {
        $data = new TestClass();
        $anotherData = [];
    }

    return [
        $data,
        // Or: clone $data
        $anotherData,
    ];
}

public static function setUpBeforeClass()
{
    list(self::$sampleJson, self::$sampleData) = self::getData(); 
}

public function sampleProvider()
{
    $data = self::getData();

    return [
        $data
    ];
}