Add test for variable description

Author: ruudk

tests/PHPStan/Testing/TypeInferenceTestCaseTest.php

@@ -4,6 +4,7 @@
 
 use PHPStan\File\FileHelper;
 use PHPUnit\Framework\AssertionFailedError;
+use function array_values;
 use function sprintf;
 
 final class TypeInferenceTestCaseTest extends TypeInferenceTestCase
@@ -90,4 +91,14 @@ public function testFileAssertionFailedErrors(string $filePath, string $errorMes
 		$this->gatherAssertTypes($filePath);
 	}
 
+	public function testVariableOrOffsetDescription(): void
+	{
+		$filePath = __DIR__ . '/data/assert-certainty-variable-or-offset.php';
+
+		[$variableAssert, $offsetAssert] = array_values($this->gatherAssertTypes($filePath));
+
+		$this->assertSame('variable $context', $variableAssert[4]);
+		$this->assertSame("offset 'email'", $offsetAssert[4]);
+	}
+
 }

tests/PHPStan/Testing/data/assert-certainty-variable-or-offset.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace AssertCertaintyVariableOrOffset;
+
+use PHPStan\TrinaryLogic;
+use function PHPStan\Testing\assertVariableCertainty;
+
+/**
+ * @param array{} $context
+ */
+function someMethod(array $context) : void
+{
+	assertVariableCertainty(TrinaryLogic::createNo(), $context);
+	assertVariableCertainty(TrinaryLogic::createYes(), $context['email']);
+}