Issue #3333776: Fatal error when trying to display inline a SVG image that does not exist and with stage_file_proxy module enabled

tests/src/Functional/Plugin/Field/FieldFormatter/SvgImageFieldFormatterTest.php

+<?php
+
+namespace Drupal\Tests\svg_image_field\Functional\Plugin\Field\FieldFormatter;
+
+use Drupal\Tests\svg_image_field\Functional\SvgImageFieldBrowserTestBase;
+
+/**
+ * Tests for the field formatter "svg_image_field_formatter".
+ *
+ * @group svg_image_field
+ */
+class SvgImageFieldFormatterTest extends SvgImageFieldBrowserTestBase {
+
+  /**
+   * Tests displaying a SVG image using the default settings.
+   */
+  public function testDisplayImage() {
+    $this->createSvgImageField('field_svg', 'article', ['uri_scheme' => 'public']);
+
+    // Create a node.
+    $image_uri = $this->getTestImage();
+    $this->uploadNodeImage($image_uri, 'field_svg', 'article', 'svg1');
+
+    // Load the file.
+    $file = $this->container->get('entity_type.manager')
+      ->getStorage('file')
+      ->load(1);
+
+    // Assert that the SVG image is displayed.
+    $this->assertSession()->elementsCount('xpath', '//img[@src="' . $file->createFileUrl() . '" and @alt="svg1" and @width="25" and @height="25"]', 1);
+
+    // Verify that the image can be downloaded.
+    $this->assertEquals(file_get_contents($image_uri), $this->drupalGet($file->createFileUrl(FALSE)), 'File was downloaded successfully.');
+  }
+
+  /**
+   * Tests displaying a SVG image inline.
+   */
+  public function testDisplayImageInline() {
+    $storage_settings = ['uri_scheme' => 'public'];
+    $formatter_settings = [
+      'inline' => TRUE,
+    ];
+    $this->createSvgImageField('field_svg', 'article', $storage_settings, [], [], $formatter_settings);
+
+    // Create a node.
+    $this->uploadNodeImage($this->getTestImage(), 'field_svg', 'article', 'svg1');
+
+    // Assert that the SVG is displayed inline.
+    $this->assertSession()->elementsCount('xpath', '//svg[@width="25" and @height="25"]', 1);
+  }
+
+  /**
+   * Tests that node gets displayed when a SVG image field is missing.
+   */
+  public function testDisplayMissingImageInline() {
+    $storage_settings = ['uri_scheme' => 'public'];
+    $formatter_settings = [
+      'inline' => TRUE,
+    ];
+    $this->createSvgImageField('field_svg', 'article', $storage_settings, [], [], $formatter_settings);
+
+    // Create a node.
+    $nid = $this->uploadNodeImage($this->getTestImage(), 'field_svg', 'article', 'svg1');
+
+    // Remove the image and clear caches.
+    $file = $this->container->get('entity_type.manager')
+      ->getStorage('file')
+      ->load(1);
+    unlink($file->uri->value);
+    drupal_flush_all_caches();
+
+    // Assert that the file no longer exists.
+    $this->drupalGet($file->createFileUrl(FALSE));
+    $this->assertSession()->statusCodeEquals(404);
+
+    // Assert that the node still can get displayed.
+    $this->drupalGet('node/' . $nid);
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertSession()->pageTextContains('Foo');
+  }
+
+  /**
+   * Tests missing svg image with stage_file_proxy module enabled.
+   */
+  public function testDisplayMissingImageInlineWithStageFileProxy() {
+    $this->assertTrue($this->container->get('module_installer')->install(['stage_file_proxy']));
+    $this->testDisplayMissingImageInline();
+  }
+
+}