diff --git a/lib/filebrowser/tests/file_browser_test.php b/lib/filebrowser/tests/file_browser_test.php
new file mode 100644
index 00000000000..3ce057026f3
--- /dev/null
+++ b/lib/filebrowser/tests/file_browser_test.php
@@ -0,0 +1,244 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Unit tests for file browser
+ *
+ * @package    core_files
+ * @copyright  2017 Marina Glancy
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * Unit tests for file browser
+ *
+ * @package    core_files
+ * @copyright  2017 Marina Glancy
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class file_browser_testcase extends advanced_testcase {
+
+    /** @var stdClass */
+    protected $course1;
+    /** @var stdClass */
+    protected $course2;
+    /** @var stdClass */
+    protected $module1;
+    /** @var stdClass */
+    protected $module2;
+    /** @var stdClass */
+    protected $course1filerecord;
+    /** @var stdClass */
+    protected $teacher;
+    /** @var stdClass */
+    protected $teacherrole;
+
+    /**
+     * Set up
+     */
+    public function setUp() {
+        global $DB;
+        $this->resetAfterTest();
+
+        $this->setAdminUser();
+
+        $this->getDataGenerator()->create_category(); // Empty category.
+        $this->course1 = $this->getDataGenerator()->create_course(); // Empty course.
+
+        $this->course2 = $this->getDataGenerator()->create_course();
+
+        // Add a file to course1 summary.
+        $coursecontext1 = context_course::instance($this->course1->id);
+        $this->course1filerecord = array('contextid' => $coursecontext1->id,
+            'component' => 'course',
+            'filearea' => 'summary',
+            'itemid' => '0',
+            'filepath' => '/',
+            'filename' => 'summaryfile.jpg');
+        $fs = get_file_storage();
+        $fs->create_file_from_string($this->course1filerecord, 'IMG');
+
+        $this->module1 = $this->getDataGenerator()->create_module('resource', ['course' => $this->course2->id]); // Contains 1 file.
+        $this->module2 = $this->getDataGenerator()->create_module('assign', ['course' => $this->course2->id]); // Contains no files.
+
+        $this->teacher = $this->getDataGenerator()->create_user();
+        $this->teacherrole = $DB->get_record('role', array('shortname' => 'editingteacher'));
+        $this->getDataGenerator()->enrol_user($this->teacher->id, $this->course1->id, $this->teacherrole->id);
+        $this->getDataGenerator()->enrol_user($this->teacher->id, $this->course2->id, $this->teacherrole->id);
+
+        $this->setUser($this->teacher);
+    }
+
+    /**
+     * Test "Server files" from the system context
+     */
+    public function test_file_info_context_system() {
+
+        // There is one non-empty category child and two category children.
+
+        $browser = get_file_browser();
+        $fileinfo = $browser->get_file_info(context_system::instance());
+        $this->assertNotEmpty($fileinfo->count_non_empty_children());
+        $this->assertEquals(1, count($fileinfo->get_non_empty_children()));
+        $categorychildren = array_filter($fileinfo->get_children(), function($a) {
+            return $a instanceof file_info_context_coursecat;
+        });
+        $this->assertEquals(2, count($categorychildren));
+    }
+
+    /**
+     * Test "Server files" from the system context, hide Misc category
+     */
+    public function test_file_info_context_system_hidden() {
+
+        // Hide the course category that contains our two courses. Teacher does not have cap to view hidden categories.
+        coursecat::get($this->course1->category)->update(['visible' => 0]);
+
+        // We should have two non-empty children in system context (courses).
+        $browser = get_file_browser();
+        $fileinfo = $browser->get_file_info(context_system::instance());
+        $this->assertNotEmpty($fileinfo->count_non_empty_children());
+        $this->assertEquals(2, count($fileinfo->get_non_empty_children()));
+
+        // Should be 1 category children (empty category).
+        $categorychildren = array_filter($fileinfo->get_children(), function($a) {
+            return $a instanceof file_info_context_coursecat;
+        });
+        $this->assertEquals(1, count($categorychildren));
+
+        // Should be 2 course children - courses that belonged to hidden subcategory are now direct children of "System".
+        $coursechildren = array_filter($fileinfo->get_children(), function($a) {
+            return $a instanceof file_info_context_course;
+        });
+        $this->assertEquals(2, count($coursechildren));
+    }
+
+    /**
+     * Test "Server files" from the course category context
+     */
+    public function test_file_info_context_coursecat() {
+
+        // There are two non-empty courses.
+
+        $browser = get_file_browser();
+        $fileinfo = $browser->get_file_info(context_coursecat::instance($this->course2->category));
+        $this->assertNotEmpty($fileinfo->count_non_empty_children());
+        $this->assertEquals(2, count($fileinfo->get_non_empty_children()));
+        $coursechildren = array_filter($fileinfo->get_children(), function($a) {
+            return $a instanceof file_info_context_course;
+        });
+        $this->assertEquals(2, count($coursechildren));
+    }
+
+    /**
+     * Test "Server files" from the course category context, only look for .jpg
+     */
+    public function test_file_info_context_coursecat_jpg() {
+
+        // There is one non-empty category child and two category children.
+
+        $browser = get_file_browser();
+        $fileinfo = $browser->get_file_info(context_system::instance());
+        $this->assertNotEmpty($fileinfo->count_non_empty_children(['.jpg']));
+        $this->assertEquals(1, count($fileinfo->get_non_empty_children(['.jpg'])));
+    }
+
+    /**
+     * Test "Server files" from the course context (course1)
+     */
+    public function test_file_info_context_course_1() {
+
+        $browser = get_file_browser();
+        $fileinfo = $browser->get_file_info(context_course::instance($this->course1->id));
+        // Fileinfo element has only one non-empty child - "Course summary" file area.
+        $this->assertNotEmpty($fileinfo->count_non_empty_children());
+        $nonemptychildren = $fileinfo->get_non_empty_children();
+        $this->assertEquals(1, count($nonemptychildren));
+        $child = reset($nonemptychildren);
+        $this->assertTrue($child instanceof file_info_stored);
+        $this->assertEquals(['filename' => '.'] + $this->course1filerecord, $child->get_params());
+        // Filearea "Course summary" has a child that is the actual image file.
+        $this->assertEquals($this->course1filerecord, $child->get_children()[0]->get_params());
+
+        // There are six course-level file areas and no modules in this course.
+        $allchildren = $fileinfo->get_children();
+        $this->assertEquals(6, count($allchildren));
+        $modulechildren = array_filter($allchildren, function($a) {
+            return $a instanceof file_info_context_module;
+        });
+        $this->assertEquals(0, count($modulechildren));
+
+        // Admin can see seven course-level file areas.
+        $this->setAdminUser();
+        $fileinfo = $browser->get_file_info(context_course::instance($this->course1->id));
+        $this->assertEquals(7, count($fileinfo->get_children()));
+    }
+
+    /**
+     * Test "Server files" from the course context (course1)
+     */
+    public function test_file_info_context_course_2() {
+
+        // 2. Start from the course level.
+        $browser = get_file_browser();
+        $fileinfo = $browser->get_file_info(context_course::instance($this->course2->id));
+        $this->assertNotEmpty($fileinfo->count_non_empty_children());
+        $nonemptychildren = $fileinfo->get_non_empty_children();
+        $this->assertEquals(1, count($nonemptychildren));
+        $child = reset($nonemptychildren);
+        $this->assertTrue($child instanceof file_info_context_module);
+        $this->assertEquals($this->module1->name.' (File)', $child->get_visible_name());
+        $this->assertEquals(1, count($child->get_non_empty_children()));
+        $this->assertEquals(1, $child->count_non_empty_children());
+        $modulechildren = array_filter($fileinfo->get_children(), function($a) {
+            return $a instanceof file_info_context_module;
+        });
+        $this->assertEquals(2, count($modulechildren));
+    }
+
+    /**
+     * Test "Server files" from the course context (module1)
+     */
+    public function test_file_info_context_module_1() {
+
+        $module1context = context_module::instance($this->module1->cmid);
+        $browser = get_file_browser();
+        $fileinfo = $browser->get_file_info($module1context);
+        $this->assertEquals($this->module1->name . ' (File)', $fileinfo->get_visible_name());
+        $this->assertNotEmpty($fileinfo->count_non_empty_children());
+        $nonemptychildren = $fileinfo->get_non_empty_children();
+        $this->assertEquals(1, count($nonemptychildren));
+        $child = reset($nonemptychildren);
+        $this->assertTrue($child instanceof file_info_stored);
+    }
+
+    /**
+     * Test "Server files" from the course context (module1)
+     */
+    public function test_file_info_context_module_2() {
+
+        $module2context = context_module::instance($this->module2->cmid);
+        $browser = get_file_browser();
+        $fileinfo = $browser->get_file_info($module2context);
+        $this->assertEquals($this->module2->name.' (Assignment)', $fileinfo->get_visible_name());
+        $this->assertEmpty($fileinfo->count_non_empty_children());
+        $nonemptychildren = $fileinfo->get_non_empty_children();
+        $this->assertEquals(0, count($nonemptychildren));
+
+    }
+}