environment: Port environment.js to be an ES module

Removes the init() function in favor of executing all environment
changes when the file is imported.

Additionally ports all unit tests using imports.gi.environment.init() to
use the updated module.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2822>

tests/unit/highlighter.js

@@ -5,9 +5,7 @@
 const JsUnit = imports.jsUnit;
 import Pango from 'gi://Pango';
 
-const Environment = imports.ui.environment;
-Environment.init();
-
+import '../../js/ui/environment.js';
 const Util = imports.misc.util;
 
 const tests = [

tests/unit/insertSorted.js

@@ -1,12 +1,13 @@
 /* -*- mode: js2; js2-basic-offset: 4; indent-tabs-mode: nil -*- */
 
 // Test cases for Util.insertSorted
-import * as Assertions from '../common/assertions.js';
 
 // Needed so that Util can bring some UI stuff
 // we don't actually use
-const Environment = imports.ui.environment;
-Environment.init();
+import '../../js/ui/environment.js';
+
+import * as Assertions from '../common/assertions.js';
+
 const Util = imports.misc.util;
 
 let arrayInt = [1, 2, 3, 5, 6];

tests/unit/jsParse.js

@@ -4,9 +4,9 @@
 
 const JsUnit = imports.jsUnit;
 
+import '../../js/ui/environment.js';
+
 import * as Assertions from '../common/assertions.js';
-const Environment = imports.ui.environment;
-Environment.init();
 
 const JsParse = imports.misc.jsParse;
 

tests/unit/markup.js

@@ -5,8 +5,7 @@
 const JsUnit = imports.jsUnit;
 import Pango from 'gi://Pango';
 
-const Environment = imports.ui.environment;
-Environment.init();
+import '../../js/ui/environment.js';
 
 imports.ui.main; // eslint-disable-line no-unused-expressions
 const MessageList = imports.ui.messageList;

tests/unit/signalTracker.js

@@ -2,16 +2,14 @@
 
 // Test cases for version comparison
 
+import '../../js/ui/environment.js';
 import GObject from 'gi://GObject';
 
 const JsUnit = imports.jsUnit;
 const Signals = imports.misc.signals;
 
-const Environment = imports.ui.environment;
 const {TransientSignalHolder, registerDestroyableType} = imports.misc.signalTracker;
 
-Environment.init();
-
 const Destroyable = GObject.registerClass({
     Signals: {'destroy': {}},
 }, class Destroyable extends GObject.Object {});

tests/unit/url.js

@@ -4,8 +4,7 @@
 
 const JsUnit = imports.jsUnit;
 
-const Environment = imports.ui.environment;
-Environment.init();
+import '../../js/ui/environment.js';
 
 const Util = imports.misc.util;
 

tests/unit/versionCompare.js

@@ -4,8 +4,7 @@
 
 const JsUnit = imports.jsUnit;
 
-const Environment = imports.ui.environment;
-Environment.init();
+import '../../js/ui/environment.js';
 
 const Util = imports.misc.util;