Make StatementList Comparable and Countable

Author: JeroenDeDauw

src/Claim/ClaimList.php

@@ -10,7 +10,7 @@
 use Wikibase\DataModel\Snak\Snaks;
 
 /**
- * Ordered, non-unique, collection of Claim objects.
+ * Ordered, non-unique, mutable, collection of Claim objects.
  * Provides various filter operations though does not do any indexing by default.
  *
  * @since 1.0

src/Statement/StatementList.php

@@ -14,15 +14,15 @@
 use Wikibase\DataModel\Snak\Snaks;
 
 /**
- * Ordered, non-unique, collection of Statement objects.
+ * Ordered, non-unique, mutable, collection of Statement objects.
  * Provides various filter operations though does not do any indexing by default.
  *
  * @since 1.0
  *
  * @licence GNU GPL v2+
  * @author Jeroen De Dauw < jeroendedauw@gmail.com >
  */
-class StatementList implements \IteratorAggregate {
+class StatementList implements \IteratorAggregate, \Comparable, \Countable {
 
 	/**
 	 * @var Statement[]
@@ -142,4 +142,45 @@ public function toArray() {
 		return $this->statements;
 	}
 
+	/**
+	 * @see Countable::count
+	 * @return int
+	 */
+	public function count() {
+		return count( $this->statements );
+	}
+
+	/**
+	 * @see Comparable::equals
+	 *
+	 * @param mixed $statementList
+	 *
+	 * @return boolean
+	 */
+	public function equals( $statementList ) {
+		if ( !( $statementList instanceof self ) ) {
+			return false;
+		}
+
+		if ( $this->count() !== $statementList->count() ) {
+			return false;
+		}
+
+		return $this->statementsEqual( $statementList->statements );
+	}
+
+	private function statementsEqual( array $statements ) {
+		reset( $statements );
+
+		foreach ( $this->statements as $statement ) {
+			if ( !$statement->equals( current( $statements ) ) ) {
+				return false;
+			}
+
+			next( $statements );
+		}
+
+		return true;
+	}
+
 }

tests/unit/Statement/StatementListTest.php

@@ -248,4 +248,96 @@ public function testGivenNonTraversable_constructorThrowsException() {
 		new StatementList( null );
 	}
 
+	public function testCountForEmptyList() {
+		$list = new StatementList();
+		$this->assertSame( 0, count( $list ) );
+		$this->assertSame( 0, $list->count() );
+	}
+
+	public function testCountForNonEmptyList() {
+		$list = new StatementList( array(
+			$this->getStatementWithSnak( 1, 'foo' ),
+			$this->getStatementWithSnak( 2, 'bar' ),
+		) );
+
+		$this->assertSame( 2, $list->count() );
+	}
+
+	/**
+	 * @dataProvider statementArrayProvider
+	 */
+	public function testGivenIdenticalLists_equalsReturnsTrue( array $statements ) {
+		$firstStatements = new StatementList( $statements );
+		$secondStatements = new StatementList( $statements );
+
+		$this->assertTrue( $firstStatements->equals( $secondStatements ) );
+	}
+
+	public function statementArrayProvider() {
+		return array(
+			array(
+				array(
+					$this->getStatementWithSnak( 1, 'foo' ),
+					$this->getStatementWithSnak( 2, 'bar' ),
+				)
+			),
+
+			array(
+				array(
+					$this->getStatementWithSnak( 1, 'foo' ),
+				)
+			),
+
+			array(
+				array()
+			),
+		);
+	}
+
+	public function testGivenDifferentLists_equalsReturnsFalse() {
+		$firstStatements = new StatementList( array(
+			$this->getStatementWithSnak( 1, 'foo' ),
+			$this->getStatementWithSnak( 2, 'bar' ),
+		) );
+
+		$secondStatements = new StatementList( array(
+			$this->getStatementWithSnak( 1, 'foo' ),
+			$this->getStatementWithSnak( 2, 'SPAM' ),
+		) );
+
+		$this->assertFalse( $firstStatements->equals( $secondStatements ) );
+	}
+
+	public function testGivenListsWithDifferentDuplicates_equalsReturnsFalse() {
+		$firstStatements = new StatementList( array(
+			$this->getStatementWithSnak( 1, 'foo' ),
+			$this->getStatementWithSnak( 1, 'foo' ),
+			$this->getStatementWithSnak( 2, 'bar' ),
+		) );
+
+		$secondStatements = new StatementList( array(
+			$this->getStatementWithSnak( 1, 'foo' ),
+			$this->getStatementWithSnak( 2, 'bar' ),
+			$this->getStatementWithSnak( 2, 'bar' ),
+		) );
+
+		$this->assertFalse( $firstStatements->equals( $secondStatements ) );
+	}
+
+	public function testGivenListsWithDifferentOrder_equalsReturnsFalse() {
+		$firstStatements = new StatementList( array(
+			$this->getStatementWithSnak( 1, 'foo' ),
+			$this->getStatementWithSnak( 2, 'bar' ),
+			$this->getStatementWithSnak( 3, 'baz' ),
+		) );
+
+		$secondStatements = new StatementList( array(
+			$this->getStatementWithSnak( 1, 'foo' ),
+			$this->getStatementWithSnak( 3, 'baz' ),
+			$this->getStatementWithSnak( 2, 'bar' ),
+		) );
+
+		$this->assertFalse( $firstStatements->equals( $secondStatements ) );
+	}
+
 }