Test Page constraint

Author: Naktibalda

src/Constraint/Page.php

@@ -82,6 +82,6 @@ protected function uriMessage(string $onPage = ''): string
         if (!$this->uri) {
             return '';
         }
-        return " {$onPage} {$this->uri}";
+        return "{$onPage} {$this->uri}";
     }
 }

tests/Constraint/PageTest.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace Tests\Codeception\Constraint;
+
+use Codeception\Constraint\Page;
+use PHPUnit\Framework\AssertionFailedError;
+use PHPUnit\Framework\TestCase;
+
+class PageTest extends TestCase
+{
+    public function testPassesIfPageContainsString(): void
+    {
+        $constraint = new Page('text', 'uri');
+        $this->assertNull($constraint->evaluate('long text string'));
+    }
+
+    public function testFailsIfPageDoesntContainString(): void
+    {
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage(<<<EOT
+        Failed asserting that on page uri
+        --> other string
+        --> contains "text".
+        EOT
+        );
+
+        $constraint = new Page('text', 'uri');
+        $this->assertNull($constraint->evaluate('other string'));
+    }
+}