--- /dev/null
+<?php
+
+namespace Drupal\Tests\drupalmoduleupgrader\Unit\Plugin\DMU\Fixer;
+
+use Drupal\drupalmoduleupgrader\Plugin\DMU\Fixer\Disable;
+use Drupal\drupalmoduleupgrader\Plugin\DMU\Indexer\FunctionCalls;
+use Drupal\Tests\drupalmoduleupgrader\Unit\TestBase;
+
+/**
+ * @group DMU.Fixer
+ *
+ * @TODO Add a test of the 'where' configuration option.
+ */
+class DisableTest extends TestBase {
+
+ public function test() {
+ $code = <<<'END'
+<?php
+
+variable_get('foo');
+END;
+ $this->dir->getChild('foo.module')->setContent(rtrim($code));
+
+ $indexer = new FunctionCalls([], 'function', ['exclude' => []], $this->db, $this->target);
+ $indexer->build();
+
+ $this
+ ->container
+ ->get('plugin.manager.drupalmoduleupgrader.indexer')
+ ->method('createInstance')
+ ->with('function_call')
+ ->willReturn($indexer);
+
+ $config = [
+ 'type' => 'function_call',
+ 'id' => 'variable_get',
+ 'note' => 'This is no longer kosher!',
+ ];
+ $plugin = new Disable($config, uniqID(), []);
+ $plugin->setTarget($this->target);
+ $plugin->execute();
+
+ $expected = <<<END
+<?php
+
+// This is no longer kosher!
+// variable_get('foo');
+END;
+
+ // trim() makes the test pass. Go figure.
+ $this->assertEquals($expected, trim($this->dir->getChild('foo.module')->getContent()));
+ }
+
+}