Move EntityIdComposer from Wikibase to DataModelServices

src/EntityId/EntityIdComposer.php

@@ -0,0 +1,70 @@
+<?php
+
+namespace Wikibase\DataModel\Services\EntityId;
+
+use InvalidArgumentException;
+use UnexpectedValueException;
+use Wikibase\DataModel\Entity\EntityId;
+
+/**
+ * Constructs EntityId objects from entity type identifiers and unique parts of entity ID
+ * serializations. The unique part is typically the numeric part of an entity ID, excluding the
+ * static part that's the same for all IDs of that type.
+ *
+ * Meant to be the counterpart for @see Int32EntityId::getNumericId, as well as an extensible
+ * replacement for @see LegacyIdInterpreter::newIdFromTypeAndNumber.
+ *
+ * @license GPL-2.0+
+ * @author Thiemo Mättig
+ */
+class EntityIdComposer {
+
+	/**
+	 * @var callable[]
+	 */
+	private $composers;
+
+	/**
+	 * @param callable[] $composers Array mapping entity type identifiers to callables accepting a
+	 *  single mixed value, representing the unique part of an entity ID serialization, and
+	 *  returning an EntityId object.
+	 *
+	 * @throws InvalidArgumentException
+	 */
+	public function __construct( array $composers ) {
+		foreach ( $composers as $entityType => $composer ) {
+			if ( !is_string( $entityType ) || $entityType === '' || !is_callable( $composer ) ) {
+				throw new InvalidArgumentException( '$composers must map non-empty strings to callables' );
+			}
+		}
+
+		$this->composers = $composers;
+	}
+
+	/**
+	 * @param string $repositoryName
+	 * @param string $entityType
+	 * @param mixed $uniquePart
+	 *
+	 * @throws InvalidArgumentException when the entity type is not known or the unique part is not
+	 *  unique.
+	 * @throws UnexpectedValueException when the configured composer did not return an EntityId
+	 *  object.
+	 * @return EntityId
+	 */
+	public function composeEntityId( $repositoryName, $entityType, $uniquePart ) {
+		if ( !isset( $this->composers[$entityType] ) ) {
+			throw new InvalidArgumentException( 'Unknown entity type ' . $entityType );
+		}
+
+		$id = $this->composers[$entityType]( $repositoryName, $uniquePart );
+
+		if ( !( $id instanceof EntityId ) ) {
+			throw new UnexpectedValueException( 'Composer for ' . $entityType . ' is invalid' );
+		}
+
+		return $id;
+	}
+
+}
+

tests/unit/EntityId/EntityIdComposerTest.php

@@ -0,0 +1,100 @@
+<?php
+
+namespace Wikibase\DataModel\Services\Tests\EntityId;
+
+use InvalidArgumentException;
+use PHPUnit_Framework_TestCase;
+use UnexpectedValueException;
+use Wikibase\DataModel\Entity\EntityId;
+use Wikibase\DataModel\Entity\ItemId;
+use Wikibase\DataModel\Services\EntityId\EntityIdComposer;
+
+/**
+ * @covers Wikibase\DataModel\Services\EntityId\EntityIdComposer
+ *
+ * @group Wikibase
+ *
+ * @licence GNU GPL v2+
+ * @author Thiemo Mättig
+ */
+class EntityIdComposerTest extends PHPUnit_Framework_TestCase {
+
+	private function getComposer() {
+		return new EntityIdComposer( [
+			'numeric-item' => function( $repositoryName, $uniquePart ) {
+				return new ItemId( 'Q' . $uniquePart );
+			},
+			'custom-item' => function( $repositoryName, $uniquePart ) {
+				return new ItemId( 'Q100' . $uniquePart );
+			},
+		] );
+	}
+
+	public function invalidConstructorArgumentProvider() {
+		$callable = function( $repositoryName, $uniquePart ) {
+		};
+
+		return [
+			[ [ 0 => $callable ] ],
+			[ [ '' => $callable ] ],
+			[ [ 'string' => null ] ],
+			[ [ 'string' => 'not a callable' ] ],
+		];
+	}
+
+	/**
+	 * @dataProvider invalidConstructorArgumentProvider
+	 */
+	public function testGivenInvalidComposer_constructorFails( $composers ) {
+		$this->setExpectedException( InvalidArgumentException::class );
+		new EntityIdComposer( $composers );
+	}
+
+	public function testGivenInvalidCallback_buildFails() {
+		$composer = new EntityIdComposer( [
+			'item' => function( $repositoryName, $uniquePart ) {
+				return null;
+			},
+		] );
+		$this->setExpectedException( UnexpectedValueException::class );
+		$composer->composeEntityId( '', 'item', 1 );
+	}
+
+	public function validUniquePartProvider() {
+		return [
+			'int' => [ 'numeric-item', 3, new ItemId( 'Q3' ) ],
+			'float' => [ 'numeric-item', 4.0, new ItemId( 'Q4' ) ],
+			'string' => [ 'numeric-item', '5', new ItemId( 'Q5' ) ],
+
+			'custom' => [ 'custom-item', 6, new ItemId( 'Q1006' ) ],
+		];
+	}
+
+	/**
+	 * @dataProvider validUniquePartProvider
+	 */
+	public function testGivenValidFragment_buildSucceeds( $entityType, $uniquePart, EntityId $expected ) {
+		$id = $this->getComposer()->composeEntityId( '', $entityType, $uniquePart );
+		$this->assertEquals( $expected, $id );
+	}
+
+	public function invalidUniquePartProvider() {
+		return [
+			[ null, 1 ],
+			[ 'unknown', 2 ],
+			[ 'numeric-item', null ],
+			[ 'numeric-item', new ItemId( 'Q4' ) ],
+		];
+	}
+
+	/**
+	 * @dataProvider invalidUniquePartProvider
+	 */
+	public function testGivenInvalidFragment_buildFails( $entityType, $uniquePart ) {
+		$composer = $this->getComposer();
+		$this->setExpectedException( InvalidArgumentException::class );
+		$composer->composeEntityId( '', $entityType, $uniquePart );
+	}
+
+}
+