Have StatementByGuidMap implement Countable

Author: JeroenDeDauw

src/Statement/StatementByGuidMap.php

@@ -14,7 +14,7 @@
  * @author Jeroen De Dauw < jeroendedauw@gmail.com >
  * @author Kai Nissen < kai.nissen@wikimedia.de >
  */
-class StatementByGuidMap {
+class StatementByGuidMap implements \Countable {
 
 	private $statements = array();
 
@@ -78,4 +78,12 @@ public function removeStatementWithGuid( $statementGuid ) {
 		unset( $this->statements[$statementGuid] );
 	}
 
+	/**
+	 * @see Countable::count
+	 * @return int
+	 */
+	public function count() {
+		return count( $this->statements );
+	}
+
 }

tests/unit/Statement/StatementByGuidMapTest.php

@@ -126,4 +126,19 @@ public function testCanConstructWithStatementIterable() {
 		$this->assertTrue( $statementMap->hasStatementWithGuid( 'some guid' ) );
 	}
 
+	public function testWhenMapIsEmpty_countReturnsZero() {
+		$statements = new StatementByGuidMap();
+
+		$this->assertSame( 0, $statements->count() );
+	}
+
+	public function testMapCanBePassedToCount() {
+		$statements = new StatementByGuidMap( array(
+			$this->newStatement( 1, 'some guid' ),
+			$this->newStatement( 2, 'other guid' )
+		) );
+
+		$this->assertSame( 2, count( $statements ) );
+	}
+
 }