Merge pull request #47 from packbackbooks/lti-add-get-delete

PODB-411: Add getLineItem to library

src/LtiAssignmentsGradesService.php

@@ -116,6 +116,20 @@ public function getLineItems(): array
         return $lineitems;
     }
 
+    public function getLineItem(string $url): LtiLineitem
+    {
+        if (!in_array(LtiConstants::AGS_SCOPE_LINEITEM, $this->getScope())) {
+            throw new LtiException('Missing required scope', 1);
+        }
+
+        $request = new ServiceRequest(LtiServiceConnector::METHOD_GET, $url);
+        $request->setAccept(static::CONTENTTYPE_LINEITEM);
+
+        $response = $this->makeServiceRequest($request)['body'];
+
+        return new LtiLineitem($response);
+    }
+
     private function ensureLineItemExists(LtiLineitem $lineitem = null): LtiLineitem
     {
         // If no line item is passed in, attempt to use the one associated with

tests/LtiAssignmentsGradesServiceTest.php

@@ -6,6 +6,8 @@
 use Packback\Lti1p3\Interfaces\ILtiRegistration;
 use Packback\Lti1p3\Interfaces\ILtiServiceConnector;
 use Packback\Lti1p3\LtiAssignmentsGradesService;
+use Packback\Lti1p3\LtiConstants;
+use Packback\Lti1p3\LtiLineitem;
 
 class LtiAssignmentsGradesServiceTest extends TestCase
 {
@@ -22,6 +24,32 @@ public function testItInstantiates()
         $this->assertInstanceOf(LtiAssignmentsGradesService::class, $service);
     }
 
+    public function testItGetsSingleLineItem()
+    {
+        $ltiLineitemData = [
+            'id' => 'testId',
+        ];
+
+        $serviceData = [
+            'scope' => [LtiConstants::AGS_SCOPE_LINEITEM],
+        ];
+
+        $service = new LtiAssignmentsGradesService($this->connector, $this->registration, $serviceData);
+
+        $response = [
+            'body' => $ltiLineitemData,
+        ];
+
+        $this->connector->shouldReceive('makeServiceRequest')
+            ->once()->andReturn($response);
+
+        $expected = new LtiLineitem($ltiLineitemData);
+
+        $result = $service->getLineItem('someUrl');
+
+        $this->assertEquals($expected, $result);
+    }
+
     /*
      * @todo Test this
      */