minor #45511 [Validator] Improve tests for the Image and File constraints (fancyweb)

This PR was merged into the 4.4 branch.

Discussion
----------

[Validator] Improve tests for the Image and File constraints

| Q             | A
| ------------- | ---
| Branch?       | 4.4
| Bug fix?      | no
| New feature?  | no
| Deprecations? | -
| Tickets       | -
| License       | MIT
| Doc PR        | -

For symfony/symfony#45090 but submitting it on the lowest branch possible.

Commits
-------

1a82c716ba [Validator] Improve tests for the Image and File constraints

Author: nicolas-grekas

Tests/Constraints/FileValidatorTest.php

@@ -185,6 +185,9 @@ public function testMaxSizeExceeded($bytesWritten, $limit, $sizeAsString, $limit
     public function provideMaxSizeNotExceededTests()
     {
         return [
+            // 0 has no effect
+            [100, 0],
+
             // limit in bytes
             [1000, 1000],
             [1000000, 1000000],

Tests/Constraints/Fixtures/ccc.txt

@@ -0,0 +1 @@
+foobar

Tests/Constraints/ImageValidatorTest.php

@@ -34,6 +34,7 @@ class ImageValidatorTest extends ConstraintValidatorTestCase
     protected $imagePortrait;
     protected $image4By3;
     protected $imageCorrupted;
+    protected $notAnImage;
 
     protected function createValidator()
     {
@@ -50,6 +51,7 @@ protected function setUp(): void
         $this->image4By3 = __DIR__.'/Fixtures/test_4by3.gif';
         $this->image16By9 = __DIR__.'/Fixtures/test_16by9.gif';
         $this->imageCorrupted = __DIR__.'/Fixtures/test_corrupted.gif';
+        $this->notAnImage = __DIR__.'/Fixtures/ccc.txt';
     }
 
     public function testNullIsValid()
@@ -416,4 +418,19 @@ public function testCorrupted()
             ->setCode(Image::CORRUPTED_IMAGE_ERROR)
             ->assertRaised();
     }
+
+    public function testInvalidMimeType()
+    {
+        $this->validator->validate($this->notAnImage, $constraint = new Image());
+
+        $this->assertSame('image/*', $constraint->mimeTypes);
+
+        $this->buildViolation('This file is not a valid image.')
+            ->setParameter('{{ file }}', sprintf('"%s"', $this->notAnImage))
+            ->setParameter('{{ type }}', '"text/plain"')
+            ->setParameter('{{ types }}', '"image/*"')
+            ->setParameter('{{ name }}', '"ccc.txt"')
+            ->setCode(Image::INVALID_MIME_TYPE_ERROR)
+            ->assertRaised();
+    }
 }