Issue #2832671 by tlyngej, jrockowitz: Add tests

src/Tests/ConfigIgnoreSettingsTest.php

+<?php
+
+namespace Drupal\config_ignore\Tests;
+
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Class ConfigIgnoreSettingsTest.
+ *
+ * @package Drupal\config_ignore\Tests
+ * @group config_ignore
+ */
+class ConfigIgnoreSettingsTest extends WebTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = ['config_ignore'];
+
+  /**
+   * Verify that the settings form works.
+   */
+  public function testSettingsForm() {
+    // Login with a user that has permission to import config.
+    $this->drupalLogin($this->drupalCreateUser(['import configuration']));
+
+    $edit = [
+      'ignored_config_entities' => 'config.test',
+    ];
+
+    $this->drupalPostForm('admin/config/development/configuration/ignore', $edit, t('Save configuration'));
+
+    $settings = $this->config('config_ignore.settings')->get('ignored_config_entities');
+
+    $this->assertEqual($settings, ['config.test']);
+  }
+
+}

src/Tests/ConfigIgnoreTest.php

+<?php
+
+namespace Drupal\config_ignore\Tests;
+
+use Drupal\simpletest\WebTestBase;
+use Drupal\Core\Serialization\Yaml;
+
+/**
+ * Class ConfigIgnoreTest.
+ *
+ * @package Drupal\config_ignore\Tests
+ * @group config_ignore
+ */
+class ConfigIgnoreTest extends WebTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = ['config_ignore'];
+
+  /**
+   * The profile to install as a basis for testing.
+   *
+   * We need to change it form the standard 'testing' profile as that will not
+   * print the title on the page, which we use for testing.
+   *
+   * @var string
+   */
+  protected $profile = 'minimal';
+
+  /**
+   * Verify that config can get ignored.
+   */
+  public function testValidateIgnoring() {
+
+    // Login with a user that has permission to import config.
+    $this->drupalLogin($this->drupalCreateUser(['import configuration']));
+
+    // Set the site name to a known value that we later will try and overwrite.
+    $this->config('system.site')->set('name', 'Test import')->save();
+
+    // Set the system.site:name to be ignored upon config import.
+    $this->config('config_ignore.settings')->set('ignored_config_entities', ['system.site'])->save();
+
+    // Assemble a change that will try and override the current value.
+    $config = $this->config('system.site')->set('name', 'Import has changed title');
+
+    $edit = [
+      'config_type' => 'system.simple',
+      'config_name' => $config->getName(),
+      'import' => Yaml::encode($config->get()),
+    ];
+
+    // Submit a new single item config, with the changes.
+    $this->drupalPostForm('admin/config/development/configuration/single/import', $edit, t('Import'));
+
+    $this->drupalPostForm(NULL, array(), t('Confirm'));
+
+    // Validate if the title from the imported config was rejected.
+    $this->assertText('Test import');
+
+  }
+
+}