port legacyfox to ecmascript modules

mozilla calls this 'esm-ification'. the last relevant to us modules were
ported in mozilla124[1], so this is our new minimum version. the old
version will likely be compatible with firefox up to version 128esr[2].

static imports are not supported in autoconfig scripts. i tried to keep
the diff as small as possible w.r.t comm-central's final JSMs. because
of this, we don't lazy-load any modules any more, nor provide any lazy
getters, as they would need to be loaded into a `lazy` object instead
the global (`this`) namespace, causing more churn. other than that, the
largest change was removing the now-useless Services.jsm workaround as
well as removing globalGetters for objects already loaded automatically.

[1]: https://hg.mozilla.org/mozilla-central/rev/68ba071ff6fb9978937496f9adc48e378957f594
[2]: bugzil.la/1881890

6 files changed, 19 insertions, 32 deletions

diff --git a/Makefile b/Makefile
index 9c41ab3..2dd4df0 100644
--- a/Makefile
+++ b/Makefile
@@ -3,9 +3,9 @@
 files := config.js
 files += defaults/pref/config-prefs.js
 files += legacy.manifest
-files += legacy/BootstrapLoader.jsm
-files += legacy/RDFDataSource.jsm
-files += legacy/RDFManifestConverter.jsm
+files += legacy/BootstrapLoader.sys.mjs
+files += legacy/RDFDataSource.sys.mjs
+files += legacy/RDFManifestConverter.sys.mjs
 archive = legacyfox.tar.gz
 DESTDIR ?= $(wildcard /usr/lib??/firefox/)
 
diff --git a/README b/README
index b7eace4..bc03093 100644
--- a/README
+++ b/README
@@ -8,6 +8,8 @@ Monkeypatching Firefox Quantum to run VimFx
 2. Install VimFx from https://github.com/akhodakivskiy/VimFx/releases
 
 == Notes ==
+ * LegacyFox is using ESModules and requires Firefox 124 or higher. Check out
+   the `v3.3` tag for compatibility with Firefox 68 to 128.
  * Users of firefox-esr on debian need to use the following command:
    `make DESTDIR=/usr/lib/firefox-esr install`
  * BootstrapLoader.jsm, RDFDataSource.jsm, RDFManifestConverter.jsm from their
@@ -22,4 +24,4 @@ trademark; you are not granted any right to distribute modified binary versions
 of the software containing the official branding.
 
 (C) 2018-2019 Mozilla, MPL v2
-(C) 2019-2023 //gir.st/, MPL v2
+(C) 2019-2024 //gir.st/, MPL v2
diff --git a/config.js b/config.js
index 993c6ff..07662f7 100644
--- a/config.js
+++ b/config.js
@@ -1,16 +1,15 @@
 // keep this comment
 try {
-  let {XPIDatabase} = Cu.import('resource://gre/modules/addons/XPIDatabase.jsm', {});
+  let {XPIDatabase} = ChromeUtils.importESModule('resource://gre/modules/addons/XPIDatabase.sys.mjs');
   XPIDatabase.isDisabledLegacy = (addon) => false;
   XPIDatabase.mustSign = (aType) => false;
 
-  const Services = globalThis.Services || Cu.import("resource://gre/modules/Services.jsm").Services;
   let manifest = Services.dirsvc.get('GreD', Ci.nsIFile);
   manifest.append('legacy.manifest');
   Components.manager.QueryInterface(Ci.nsIComponentRegistrar).autoRegister(manifest);
 
-  const {AddonManager} = Cu.import('resource://gre/modules/AddonManager.jsm');
-  const {BootstrapLoader} = Cu.import('resource://legacy/BootstrapLoader.jsm');
+  const {AddonManager} = ChromeUtils.importESModule('resource://gre/modules/AddonManager.sys.mjs');
+  const {BootstrapLoader} = ChromeUtils.importESModule('resource://legacy/BootstrapLoader.sys.mjs');
   AddonManager.addExternalExtensionLoader(BootstrapLoader);
 } catch(ex) {
   Components.utils.reportError(ex.message);
diff --git a/legacy/BootstrapLoader.jsm b/legacy/BootstrapLoader.sys.mjs
index a4010b3..80fc61d 100644
--- a/legacy/BootstrapLoader.jsm
+++ b/legacy/BootstrapLoader.sys.mjs
@@ -6,19 +6,12 @@
 
 var EXPORTED_SYMBOLS = ["BootstrapLoader"];
 
-const {AddonManager} = ChromeUtils.import("resource://gre/modules/AddonManager.jsm");
-const {XPCOMUtils} = ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
+import {AddonManager} from "resource://gre/modules/AddonManager.sys.mjs";
+import {AddonInternal} from "resource://gre/modules/addons/XPIDatabase.sys.mjs";
+import {InstallRDF} from "resource://legacy/RDFManifestConverter.sys.mjs";
+import {XPIProvider} from "resource://gre/modules/addons/XPIProvider.sys.mjs";
 
-XPCOMUtils.defineLazyModuleGetters(this, {
-  AddonInternal: "resource://gre/modules/addons/XPIDatabase.jsm",
-  InstallRDF: "resource://legacy/RDFManifestConverter.jsm",
-});
-const Services = globalThis.Services || ChromeUtils.import("resource://gre/modules/Services.jsm").Services;
-
-(ChromeUtils.defineLazyGetter||XPCOMUtils.defineLazyGetter)(this, "BOOTSTRAP_REASONS", () => {
-  const {XPIProvider} = ChromeUtils.import("resource://gre/modules/addons/XPIProvider.jsm");
-  return XPIProvider.BOOTSTRAP_REASONS;
-});
+const BOOTSTRAP_REASONS = XPIProvider.BOOTSTRAP_REASONS;
 
 var logger = console.createInstance({ prefix: "addons.bootstrap" });
 
@@ -99,7 +92,7 @@ function buildJarURI(aJarfile, aPath) {
   return Services.io.newURI(uri);
 }
 
-var BootstrapLoader = {
+export var BootstrapLoader = {
   name: "bootstrap",
   manifestFile: "install.rdf",
   async loadManifest(pkg) {
@@ -306,7 +299,7 @@ var BootstrapLoader = {
     try {
       Object.assign(sandbox, BOOTSTRAP_REASONS);
 
-      (ChromeUtils.defineLazyGetter||XPCOMUtils.defineLazyGetter)(sandbox, "console", () =>
+      ChromeUtils.defineLazyGetter(sandbox, "console", () =>
         console.createInstance({ consoleID: `addon/${addon.id}` }));
 
       Services.scriptloader.loadSubScript(uri, sandbox);
diff --git a/legacy/RDFDataSource.jsm b/legacy/RDFDataSource.sys.mjs
index 579d075..27687ba 100644
--- a/legacy/RDFDataSource.jsm
+++ b/legacy/RDFDataSource.sys.mjs
@@ -134,12 +134,6 @@ const USE_RDFNS_ATTR = false;
 var EXPORTED_SYMBOLS = ["RDFLiteral", "RDFIntLiteral", "RDFDateLiteral",
                         "RDFBlankNode", "RDFResource", "RDFDataSource"];
 
-const {XPCOMUtils} = ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
-
-XPCOMUtils.defineLazyGlobalGetters(this, ["DOMParser", "Element", "XMLSerializer", "fetch"]);
-
-const Services = globalThis.Services || ChromeUtils.import("resource://gre/modules/Services.jsm").Services;
-
 function isAttr(obj) {
   return obj && typeof obj == "object" && ChromeUtils.getClassName(obj) == "Attr";
 }
@@ -1113,7 +1107,7 @@ class RDFBlankNode extends RDFSubject {
  * changed as assertions are added and removed to the RDF. Pass a null document
  * to start with an empty graph.
  */
-class RDFDataSource {
+export class RDFDataSource {
   constructor(document) {
     // All known resources, indexed on URI
     this._resources = {};
diff --git a/legacy/RDFManifestConverter.jsm b/legacy/RDFManifestConverter.sys.mjs
index cb01f6a..12abd27 100644
--- a/legacy/RDFManifestConverter.jsm
+++ b/legacy/RDFManifestConverter.sys.mjs
@@ -5,8 +5,7 @@
 
 var EXPORTED_SYMBOLS = ["InstallRDF"];
 
-ChromeUtils.defineModuleGetter(this, "RDFDataSource",
-                               "resource://legacy/RDFDataSource.jsm");
+import {RDFDataSource} from "resource://legacy/RDFDataSource.sys.mjs";
 
 const RDFURI_INSTALL_MANIFEST_ROOT = "urn:mozilla:install-manifest";
 
@@ -40,7 +39,7 @@ class Manifest {
   }
 }
 
-class InstallRDF extends Manifest {
+export class InstallRDF extends Manifest {
   _readProps(source, obj, props) {
     for (let prop of props) {
       let val = getProperty(source, prop);