Replace JS features not supported on ATN

Sadly, the offical add-on platform currently requires all uploads to
pass a very outdated linter, which does not yet support recent
JavaScript features. This commit thus replaces features that are not
supported on ATN temporarily.

Once ATN is updated to support ES2020 features, these changes should get
reverted for consistency with the official API draft repository.

src/experiments/calendar/ext-calendar-utils.jsm

@@ -104,9 +104,9 @@ function propsToItem(props, baseItem) {
     throw new ExtensionError("Invalid item type: " + props.type);
   }
 
-  if (props.formats?.use == "ical") {
+  if (props.formats && props.formats.use == "ical") {
     item.icalString = props.formats.ical;
-  } else if (props.formats?.use == "jcal") {
+  } else if (props.formats && props.formats.use == "jcal") {
     item.icalString = ICAL.stringify(props.formats.jcal);
   } else {
     if (props.id) {
@@ -165,7 +165,7 @@ function convertItem(item, options, extension) {
     let cache = getCachedCalendar(item.calendar);
     try {
       // TODO This is a sync operation. Not great. Can we optimize this?
-      props.metadata = JSON.parse(cache.getMetaData(item.hashId)) ?? {};
+      props.metadata = JSON.parse(cache.getMetaData(item.hashId)) || {};
     } catch (e) {
       // Ignore json parse errors
     }
@@ -213,8 +213,8 @@ function convertAlarm(item, alarm) {
   return {
     itemId: item.id,
     action: alarm.action.toLowerCase(),
-    date: alarm.alarmDate?.icalString,
-    offset: alarm.offset?.icalString,
+    date: alarm.alarmDate ? alarm.alarmDate.icalString : undefined,
+    offset: alarm.offset ? alarm.offset.icalString : undefined,
     related: ALARM_RELATED_MAP[alarm.related],
   };
 }

src/experiments/calendar/parent/ext-calendar-calendars.js

@@ -206,7 +206,7 @@ this.calendar_calendars = class extends ExtensionAPI {
                       fire.sync(converted, { [name]: value });
                       break;
                     case "uri":
-                      fire.sync(converted, { url: value?.spec });
+                      fire.sync(converted, { url: value ? value.spec : undefined });
                       break;
                     case "disabled":
                       fire.sync(converted, { enabled: !value });

src/experiments/calendar/parent/ext-calendar-items.js

@@ -68,7 +68,7 @@ this.calendar_items = class extends ExtensionAPI {
             if (!oldItem) {
               throw new ExtensionError("Could not find item " + id);
             }
-            let newItem = propsToItem(updateProperties, oldItem?.clone());
+            let newItem = propsToItem(updateProperties, oldItem ? oldItem.clone() : undefined);
             newItem.calendar = calendar.superCalendar;
 
             if (updateProperties.metadata && isOwnCalendar(calendar, context.extension)) {

src/experiments/calendar/parent/ext-calendar-provider.js

@@ -9,8 +9,6 @@ var { cal } = ChromeUtils.import("resource:///modules/calendar/calUtils.jsm");
 var { ExtensionAPI, EventManager } = ExtensionCommon;
 
 class ExtCalendarProvider extends cal.provider.BaseClass {
-  QueryInterface = ChromeUtils.generateQI(["calICalendar", "calIChangeLog", "calISchedulingSupport"]);
-
   static register(extension) {
     let calmgr = cal.getCalendarManager();
     let type = "ext-" + extension.id;
@@ -34,14 +32,17 @@ class ExtCalendarProvider extends cal.provider.BaseClass {
 
   constructor() {
     super();
+    this.QueryInterface = ChromeUtils.generateQI(["calICalendar", "calIChangeLog", "calISchedulingSupport"]);
     this.initProviderBase();
   }
 
   get providerID() {
     return this.extension.id;
   }
 
-  canRefresh = true;
+  get canRefresh() {
+    return true;
+  }
 
   get id() {
     return super.id;
@@ -83,9 +84,9 @@ class ExtCalendarProvider extends cal.provider.BaseClass {
         break;
 
       case "capabilities.timezones.floating.supported":
-        return !(this.capabilities.timezones?.floating === false);
+        return !(this.capabilities.timezones && this.capabilities.timezones.floating === false);
       case "capabilities.timezones.UTC.supported":
-        return !(this.capabilities.timezones?.UTC === false);
+        return !(this.capabilities.timezones && this.capabilities.timezones.UTC === false);
       case "capabilities.attachments.supported":
         return !(this.capabilities.attachments === false);
       case "capabilities.priority.supported":
@@ -94,18 +95,18 @@ class ExtCalendarProvider extends cal.provider.BaseClass {
         return !(this.capabilities.privacy === false);
       case "capabilities.privacy.values":
         return Array.isArray(this.capabilities.privacy)
-          ? this.capabilities.privacy?.map(val => val.toUpperCase())
+          ? this.capabilities.privacy.map(val => val.toUpperCase())
           : ["PUBLIC", "CONFIDENTIAL", "PRIVATE"];
       case "capabilities.categories.maxCount":
-        return Number.isInteger(this.capabilities.categories?.count)
-          ? this.capabilities.categories?.count
+        return this.capabilities.categories && Number.isInteger(this.capabilities.categories.count)
+          ? this.capabilities.categories.count
           : -1;
       case "capabilities.alarms.maxCount":
-        return Number.isInteger(this.capabilities.alarms?.count)
-          ? this.capabilities.alarms?.count
+        return this.capabilities.alarms && Number.isInteger(this.capabilities.alarms.count)
+          ? this.capabilities.alarms.count
           : undefined;
       case "capabilities.alarms.actionValues":
-        return this.capabilities.alarms?.actions?.map(val => val.toUpperCase()) || ["DISPLAY"];
+        return this.capabilities.alarms && this.capabilities.alarms.actions && this.capabilities.alarms.actions.map(val => val.toUpperCase()) || ["DISPLAY"];
       case "capabilities.tasks.supported":
         return !(this.capabilities.tasks === false);
       case "capabilities.events.supported":
@@ -283,7 +284,7 @@ this.calendar_provider = class extends ExtensionAPI {
     }
     let manifest = this.extension.manifest;
 
-    if (!manifest.browser_specific_settings?.gecko?.id && !manifest.applications?.gecko?.id) {
+    if (!(manifest.browser_specific_settings && manifest.browser_specific_settings.gecko && manifest.browser_specific_settings.gecko.id) && !(manifest.applications && manifest.applications.gecko && manifest.applications.gecko.id)) {
       console.warn(
         "Registering a calendar provider with a temporary id. Calendars created for this provider won't persist restarts"
       );