Extension to manage constraints in Wikibase.

dev-master 2024-04-17 07:29 UTC

This package is not auto-updated.

Last update: 2024-04-17 08:09:13 UTC


Scrutinizer Code Quality

Extension to Wikibase Repository that performs constraint checks.


  • Clone WikibaseQualityConstraints inside the extensions/ directory of your MediaWiki installations.

    cd .../extensions/
    git clone
  • Install dependencies. The simplest way is to set up composer-merge-plugin and then run composer install in the MediaWiki base directory; alternatively, you can run composer install inside the WikibaseQualityConstraints directory.

  • Load the extension.

    wfLoadExtension( 'WikibaseQualityConstraints' );
  • Run php maintenance/update.php --quick.

  • Configure the extension. You can find the configuration settings with documentation in extension.json. (Note that the variable name for LocalSettings.php always begins with wg, e. g. $wgWBQualityConstraintsClassId for the WBQualityConstraintsClassId setting.)

    • Specify the entity IDs of entities that are used to define constraints. See the “Data import” section for an automatic way to do this.

    • If you have a SPARQL endpoint, configure it in WBQualityConstraintsSparqlEndpoint.

    • Alternatively, to check “format” constraints without running a full SPARQL server, you can use the minisparql server.

  • Run php maintenance/run.php WikibaseQualityConstraints:ImportConstraintStatements.php.

Client-side script

The extension includes a client-side script that checks constraints on entity pages and displays violations on statements. It is loaded by default for all logged-in users; anonymous users can load it on a page by entering the following code into the web console:

mw.loader.load( 'wikibase.quality.constraints.gadget' );

Data import

For local development, it’s easiest to import some data from Wikidata. You can use the ImportConstraintEntities maintenance script script to do this; it will import all the required entities from Wikidata that don’t exist in your local wiki yet and then print a config snippet which you can append to your LocalSettings.php.

# working directory should be the MediaWiki installation folder, i.e. where LocalSettings.php is
php maintenance/run.php WikibaseQualityConstraints:ImportConstraintEntities.php | tee -a LocalSettings.php

(The new entities will not show up in your wiki’s recent changes until they have been processed in the job queue; try running the maintenance/runJobs.php script if it doesn’t happen automatically.)

Running the tests


There are two ways to run the tests of this extension:

  • Using the included configuration file:

    # from the MediaWiki installation folder
    composer phpunit -- -c extensions/WikibaseQualityConstraints/phpunit.xml.dist

    This creates test coverage reports (in tests/coverage/ and build/logs/clover.xml) and is therefore fairly slow.

  • Without the configuration file:

    # from the MediaWiki installation folder
    composer phpunit:entrypoint extensions/WikibaseQualityConstraints/tests/phpunit/

    This runs the tests without coverage report and is therefore much faster.


You can run the tests, combined with linting and few other tools for asserting code quality by

  # from this extension's folder
  npm install
  grunt test

Adding a new constraint type

To add a new constraint type, the following steps are necessary:

  • Define the constraint checker class.
    • It should be defined in a new file in src/ConstraintCheck/Checker/, named after the class name. It should be in the WikibaseQuality\ConstraintReport\ConstraintCheck\Checker namespace.
    • The class name should follow the constraint type name (in English), ending in “Checker”.
    • The class must implement the ConstraintChecker interface.
    • It should have at least the following class-level documentation comment:
       * @author YOUR NAME HERE
       * @license GPL-2.0-or-later
    • Any services you need (Config, EntityLookup, …) should be injected as constructor parameters.
    • If the constraint has parameters, add support for parsing them to ConstraintParameterParser (add a config setting for the associated property in extension.json and a method to parse the parameter in ConstraintParameterParser), and then add tests for them in ConstraintParameterParserTest. This should be done in a separate commit.
  • Define new messages (at least a violation message for the constraint type).
    • Define the message in i18n/en.json. A violation message should have a key like wbqc-violation-message-constraintType.
    • Document the message in i18n/qqq.json. Use the same message key, and insert the documentation in the same location where you also added the message in en.json (that is, en.json and qqq.json should contain message keys in the same order).
  • Add a configuration setting for the constraint type item ID.
    • Configuration settings are defined in extension.json, as members of the config object.
    • It should be added right after the current last …ConstraintId entry.
    • It should be named after the constraint type item’s English label, following the pattern WBQualityConstraints…ConstraintId.
    • The default value should be the item ID on Wikidata, so that no extra configuration is required for Wikidata and importing the constraint type item (see “Data import” section) works.
    • The first part of the description can be copied from similar settings, the rest should contain a short description of the constraint type.
    • The ID can always be public ("public": true).
  • Register the new constraint type checker.
    • In ConstraintCheckerServices.php, add a constant like
      public const_CHECKER = 'WBQC_…Checker';
      at the end of the list of constants. The value should be 'WBQC_' followed by the class name, and the constant name should be the class name converted to all caps separated by underscores.
    • Also in ConstraintCheckerServices.php, add a method like
       * @param MediaWikiServices|null $services
       * @return ConstraintChecker
      public static function get…Checker( MediaWikiServices $services = null ) {
      	return self::getService( $services, self::…_CHECKER );
      at the end of the class.
    • In ServiceWiring-ConstraintCheckers.php, append a new function like
      ConstraintCheckerServices::…_CHECKER => function( MediaWikiServices $services ) {
      	return newChecker(
          	// injected services
      to the array of services.
    • In ServiceWiring.php, append a new entry like
      $config->get( 'WBQualityConstraints…ConstraintId' )
      	=> ConstraintCheckerServices::get…Checker( $services ),
      to the $checkerMap array in the DELEGATING_CONSTRAINT_CHECKER function.
    • In ServicesTest.php, append a new entry like
      [ …Checker::class ],
      to the array in provideConstraintCheckerServiceClasses().
  • Add tests for the new constraint checker.
    • The test class name should be the same as the checker class name, with an additional suffix Test (i. e., …CheckerTest).
    • The test class should be placed somewhere in tests/phpunit/Checker/, either in the most suitable subdirectory or directly in that directory if none of the subdirectories are suitable. (The division into subdirectories there is dubious anyways, and we may get rid of it in the future.)
    • It should have at least the following class-level documentation comment:
       * @covers WikibaseQuality\ConstraintReport\ConstraintCheck\Checker\…Checker
       * @group WikibaseQualityConstraints
       * @author YOUR NAME HERE
       * @license GPL-2.0-or-later
    • It should have at least one test for compliance with a constraint, one test for a constraint violation, one test for behavior on a deprecated statement, and one test for the checkConstraintParameters method.
    • Use the ResultAssertions trait’s methods to check constraint check results.
    • Use the NewItem and NewStatement builders to construct test data.
    • If the checker uses a Config, use the DefaultConfig trait.
    • If the constraint has parameters, add methods for them to the ConstraintParameters trait and use it in the tests.
    • You can copy+paste a getConstraintMock function from one of the existing tests, adjusting the getConstraintTypeItemId mocked return value. (Hopefully we’ll improve this in the future.)
  • Update the tests for DelegatingConstraintChecker.
    • In DelegatingConstraintCheckerTest, add an entry for your constraint type to the $constraints array in addDBData().
    • The constraint_guid should be P1$, followed by a new UUID (e. g. cat /proc/sys/kernel/random/uuid or journalctl --new-id128).
    • The pid should be 1. (Not '1'!)
    • The constraint_type_qid should be $this->getConstraintTypeItemId( '…' ), where is just the part of the WBQualityConstraints…ConstraintId extension.json config key.
    • The constraint_parameters should be a valid JSON serialization of constraint parameters. If the constraint type doesn’t have any parameters, you can pass {}, otherwise there should ideally be methods to create the parameters in the ConstraintParameters trait so that you can use json_encode( $this->…Parameter( … ) ) (perhaps with array_merge if there are multiple parameters).
  • Ask someone with grafana-admin access to update the “constraint types” panel in the wikidata-quality board to add the new constraint type.

Adding a new allowed entity type

  • Start by adding an Item reference to extension.json. For example:
     "WBQualityConstraintsMediaInfoId": {
         "value": "Q3898244",
         "description": "The item ID of the 'MediaInfo' item, which represents the 'mediainfo' entity type for 'allowed entity types' constraints.",
         "public": true
  • The next step takes place inside src/ConstraintCheck/Helper/ConstraintParameterParser.php. The new allowed entity type should be added to the switch/case within the method parseEntityTypeItem(). Don't forget to add it to the default case as well!
  • To be able to test the newly added allowed entity type locally, please perform the steps described in section "Data import".

Chore: Dependency Updates


You can see which dependencies have new releases by first running npm ci to ensure your local dependencies are up-to-date, and then running npm outdated.

  • Jasmine 5 and Sinon 17 are declared not compatible with Node 16, which we still use in CI. Until T331180 is done, we should use the latest versions of Jasmine 4 and Sinon 16.
  • Unexpected: This shows up in the npm outdated output due to a bad “latest” tag on npm; we want to be using the highest version number (currently 13.2.1), not the one tagged as latest (currently 12.0.5).


Running composer update and composer outdated --direct will give you a list of any outdated PHP dependencies. There are currently no notes or restrictions on package updates.