test: improve test coverage

Author: g105b

src/Injector.php

@@ -81,11 +81,14 @@ private function resolveUntypedParameter(
 		ReflectionParameter $refParam,
 		array $extraArgs,
 	):mixed {
+		if(array_key_exists($refParam->getName(), $extraArgs)) {
+			return $extraArgs[$refParam->getName()];
+		}
 		if($refParam->isDefaultValueAvailable()) {
 			return $refParam->getDefaultValue();
 		}
 
-		return $extraArgs[$refParam->getName()] ?? null;
+		return null;
 	}
 
 	/** @param class-string $refParamTypeName */

test/phpunit/InjectorTest.php

@@ -4,6 +4,7 @@
 use DateTime;
 use GT\ServiceContainer\Container;
 use GT\ServiceContainer\Injector;
+use GT\ServiceContainer\ServiceNotFoundException;
 use GT\ServiceContainer\Test\Example\Greeter;
 use PHPUnit\Framework\TestCase;
 
@@ -77,4 +78,87 @@ public function testInvoke_usesExtraArgByParameterName():void {
 			$sut->invoke(null, $function, ["name" => "Cron"])
 		);
 	}
+
+	public function testInvoke_usesExtraArgByParameterType():void {
+		$dateTime = new DateTime("2026-06-22");
+		$function = function(DateTime $dateTime):string {
+			return $dateTime->format("Y-m-d");
+		};
+
+		$sut = new Injector(new Container());
+		self::assertSame(
+			"2026-06-22",
+			$sut->invoke(null, $function, [DateTime::class => $dateTime])
+		);
+	}
+
+	public function testInvoke_usesExtraArgForUntypedParameter():void {
+		$function = function($name = "World"):string {
+			return "Hello, $name!";
+		};
+
+		$sut = new Injector(new Container());
+		self::assertSame(
+			"Hello, Cron!",
+			$sut->invoke(null, $function, ["name" => "Cron"])
+		);
+	}
+
+	public function testInvoke_usesDefaultUntypedParameter():void {
+		$function = function($name = "World"):string {
+			return "Hello, $name!";
+		};
+
+		$sut = new Injector(new Container());
+		self::assertSame("Hello, World!", $sut->invoke(null, $function));
+	}
+
+	public function testInvoke_setsMissingUntypedParameterToNull():void {
+		$function = function($name):mixed {
+			return $name;
+		};
+
+		$sut = new Injector(new Container());
+		self::assertNull($sut->invoke(null, $function));
+	}
+
+	public function testInvoke_setsMissingNullableBuiltinParameterToNull():void {
+		$function = function(?string $name):mixed {
+			return $name;
+		};
+
+		$sut = new Injector(new Container());
+		self::assertNull($sut->invoke(null, $function));
+	}
+
+	public function testInvoke_throwsWhenRequiredBuiltinParameterIsMissing():void {
+		$function = function(string $name):string {
+			return $name;
+		};
+
+		$sut = new Injector(new Container());
+
+		self::expectException(ServiceNotFoundException::class);
+		$sut->invoke(null, $function);
+	}
+
+	public function testInvoke_setsMissingNullableServiceParameterToNull():void {
+		$function = function(?Greeter $greeter):mixed {
+			return $greeter;
+		};
+
+		$sut = new Injector(new Container());
+		self::assertNull($sut->invoke(null, $function));
+	}
+
+	public function testInvoke_throwsWhenRequiredServiceParameterIsMissing():void {
+		$function = function(Greeter $greeter):Greeter {
+			return $greeter;
+		};
+
+		$sut = new Injector(new Container());
+
+		self::expectException(ServiceNotFoundException::class);
+		$sut->invoke(null, $function);
+	}
 }