As a developer, I want to be able to work on the data-values libraries using the newest PHP version.
**Problem:**
Some of our [data-values libraries](https://github.com/DataValues) still use PHPUnit 4. WikibaseRepo has very clear words for this:
```lang=php,name=repo/tests/phpunit/includes/Parsers/PHPUnit4CompatTrait.php
/**
* Awful hack: several tests extend DataValues test classes. DataValues works on PHPUnit4 only, hence
* it uses setExpectedException (amongst other things). But Wikibase requires PHP 7.2+ and PHPUnit6+,
* where setExpectedException doesn't exist anymore. This was resolved by using the PHPUnit4And6Compat
* trait provided by core, but that's deprecated as of 1.34.
*
* @todo Get rid of this trait as soon as DataValues moves away from withered PHPUnit.
*/
trait PHPUnit4CompatTrait {
```
PHPUnit 4 doesn’t even work under PHP 7.4 anymore, so it’s not possible to test these libraries under the latest released PHP version.
**Example:**
[wmde/Time#149](https://github.com/wmde/Time/pull/149) is an attempt to pull data-values/time into the present day but it’s kicking and screaming and generally being annoying about it.
**Note**: Except https://github.com/wmde/Time, https://github.com/wmde/Number libraries involved here are not maintained by WMDE, therefore WMDE will only be able to provide updates and will not be in charge of releasing new versions.
**Acceptance criteria:**
[] The DataValues libraries use recent versions of PHPUnit (such as 8.5+)
[x] https://github.com/DataValues/Geo
[x] https://github.com/DataValues/DataValues (Uses PHPUnit 8 here already)
[x] https://github.com/DataValues/Interfaces
[x] https://github.com/DataValues/Common
[x] https://github.com/DataValues/Serialization
[x] https://github.com/DataValues/Validators
[x] https://github.com/DataValues/Iri
[] https://github.com/wmde/Time
[] https://github.com/wmde/Number
#patch-for-review:
- [ ] https://github.com/DataValues/DataValues/pull/59
- [x] https://github.com/DataValues/Common/pull/91
- [x] https://github.com/DataValues/Serialization/pull/42
- [x] https://github.com/DataValues/Interfaces/pull/53
- [x] https://github.com/DataValues/Geo/pull/190
- [x] https://github.com/DataValues/Validators/pull/21
- [] https://github.com/wmde/Time/pull/153 (waiting for new release of DataValue/...)
- [] https://github.com/wmde/Number/pull/130 (waiting for new release of DataValue/...)
- [x] https://github.com/DataValues/Iri/pull/2
- [ ] …