Merge branch 'mozjs102' into 'master'

Initial port to mozjs102

See merge request GNOME/gjs!765

59 files changed, 248 insertions, 189 deletions

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 1323d822..8869ed6b 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -31,7 +31,7 @@ build-alpine-image:
       mkdir -p /cwd
 
 .coverage: &coverage
-  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs91-debug
+  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs102-debug
   variables:
     coverage: '/^  lines.*(\d+\.\d+\%)/'
   script:
@@ -75,7 +75,7 @@ build-alpine-image:
 build_recommended:
   <<: *build
   stage: source_check
-  image: registry.gitlab.gnome.org/gnome/gjs:job-2153951_fedora.mozjs91-debug  # pinned on purpose
+  image: registry.gitlab.gnome.org/gnome/gjs:job-2190518_fedora.mozjs102-debug  # pinned on purpose
   variables:
     TEST_OPTS: --verbose --no-stdsplit --print-errorlogs --setup=verbose
   except:
@@ -86,7 +86,7 @@ sanitizer_gcc:
   stage: test
   tags:
     - asan # LSAN needs CAP_SYS_PTRACE
-  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs91-debug
+  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs102-debug
   variables:
     CONFIG_OPTS: -Db_sanitize=address,undefined
     TEST_OPTS: --timeout-multiplier=3 --setup=verbose
@@ -100,7 +100,7 @@ sanitizer_thread_gcc:
   allow_failure: true
   tags:
     - asan # TSAN needs CAP_SYS_PTRACE
-  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs91-debug
+  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs102-debug
   variables:
     CONFIG_OPTS: -Db_sanitize=thread
     TEST_OPTS: --timeout-multiplier=3 --setup=verbose
@@ -113,7 +113,7 @@ sanitizer_thread_gcc:
 build_maximal:
   <<: *build
   stage: test
-  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs91-debug
+  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs102-debug
   variables:
     CC: clang
     CXX: clang++
@@ -129,7 +129,7 @@ build_maximal:
 build_minimal:
   <<: *build
   stage: test
-  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs91
+  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs102
   variables:
     CONFIG_OPTS: >-
       -Dbuildtype=release
@@ -141,7 +141,7 @@ build_minimal:
 build_unity:
   <<: *build
   stage: test
-  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs91
+  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs102
   variables:
     # unity-size here is forced to use an high number to check whether we can
     # join all the sources together, but should not be used in real world to
@@ -253,7 +253,7 @@ pch_check:
 iwyu:
   when: on_success
   stage: source_check
-  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs91-debug
+  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs102-debug
   script:
     - test/test-ci.sh UPSTREAM_BASE
     - meson setup _build -Db_pch=false
@@ -304,7 +304,7 @@ coverage:
 iwyu-full:
   when: manual
   stage: manual
-  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs91-debug
+  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs102-debug
   script:
     - meson setup _build
     - ./tools/run_iwyu.sh
@@ -316,7 +316,7 @@ sanitizer_clang:
   stage: manual
   tags:
     - asan # LSAN needs CAP_SYS_PTRACE
-  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs91-debug
+  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs102-debug
   variables:
     CC: clang
     CXX: clang++
@@ -329,7 +329,7 @@ sanitizer_clang:
 installed_tests:
   <<: *build
   stage: manual
-  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs91-debug
+  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs102-debug
   variables:
     CONFIG_OPTS: -Dinstalled_tests=true -Dprefix=/usr
     TEST: skip
@@ -345,7 +345,7 @@ installed_tests:
 valgrind:
   <<: *build
   stage: manual
-  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs91-debug
+  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs102-debug
   variables:
     TEST_OPTS: --setup=valgrind
   allow_failure: true
@@ -357,7 +357,7 @@ valgrind:
 zeal_2:
   <<: *build
   stage: manual
-  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs91-debug
+  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs102-debug
   variables:
     TEST_OPTS: --setup=extra_gc
   when: manual
@@ -367,7 +367,7 @@ zeal_2:
 zeal_4:
   <<: *build
   stage: manual
-  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs91-debug
+  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs102-debug
   variables:
     TEST_OPTS: --setup=pre_verify
   when: manual
@@ -377,7 +377,7 @@ zeal_4:
 zeal_11:
   <<: *build
   stage: manual
-  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs91-debug
+  image: registry.gitlab.gnome.org/gnome/gjs:fedora.mozjs102-debug
   variables:
     TEST_OPTS: --setup=post_verify
   when: manual
diff --git a/NEWS b/NEWS
index db87d79a..6dc06d38 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,18 @@
+Version 1.73.2
+--------------
+
+- New JavaScript features! This version of GJS is based on SpiderMonkey 102, an
+  upgrade from the previous ESR (Extended Support Release) of SpiderMonkey 91.
+  Here are the highlights of the new JavaScript features.
+  For more information, look them up on MDN or devdocs.io.
+
+  * New APIs
+    + The `Object.hasOwn()` static method can be used as an easier replacement
+      for `Object.prototype.hasOwnProperty.call(...)`.
+    + `Intl.supportedValuesOf()` lets you enumerate which calendars, currencies,
+      collation strategies, numbering systems, time zones, and units are
+      available for internationalization.
+
 Version 1.73.1
 --------------
 
diff --git a/README.MSVC.md b/README.MSVC.md
index 9cf51a87..b5f54349 100644
--- a/README.MSVC.md
+++ b/README.MSVC.md
@@ -7,13 +7,13 @@ recent-enough Windows SDK from Microsoft is still required if using
 clang-cl, as we will still use items from the Windows SDK.

 

 Recent official binary installers of CLang (which contains clang-cl)

-from the LLVM website are known to work to build SpiderMonkey 91 and

+from the LLVM website are known to work to build SpiderMonkey 102 and

 GJS.

 

 You will need the following items to build GJS using Visual Studio

 or clang-cl (they can be built with Visual Studio 2015 or later,

 unless otherwise noted):

--SpiderMonkey 91.x (mozjs-91). This must be built with clang-cl as

+-SpiderMonkey 102.x (mozjs-102). This must be built with clang-cl as

  the Visual Studio  compiler is no longer supported for building this.

  Please see the below section carefully on this...

 -GObject-Introspection (G-I) 1.61.2 or later

@@ -44,8 +44,8 @@ for the suitable release series of SpiderMonkey that corresponds to
 the GJS version that is being built, as GJS depends on ESR (Extended 

 Service Release, a.k.a Long-term support) releases of SpiderMonkey.

 

-You may also be able to obtain the SpiderMonkey 91.x sources via the

-FireFox (ESR) or Thunderbird 91.x sources, in $(srcroot)/js.

+You may also be able to obtain the SpiderMonkey 102.x sources via the

+FireFox (ESR) or Thunderbird 102.x sources, in $(srcroot)/js.

 

 Please do note that the build must be done carefully, in addition to the

 official instructions that are posted on the Mozilla website:

@@ -53,7 +53,7 @@ official instructions that are posted on the Mozilla website:
 https://firefox-source-docs.mozilla.org/js/build.html

 

 You will need to create a .mozconfig file that will describe your build

-options for the build in the root directory of the Firefox/ThunderBird 91.x

+options for the build in the root directory of the Firefox/ThunderBird 102.x

 sources.  A sample content of the .mozconfig file can be added as follows:

 

 ```

@@ -66,7 +66,7 @@ ac_add_options --disable-tests
 ac_add_options --enable-optimize

 ac_add_options --disable-debug

 ac_add_options --disable-jemalloc

-ac_add_options --prefix=c:/software.b/mozjs91.bin

+ac_add_options --prefix=c:/software.b/mozjs102.bin

 ```

 

 An explanation of the lines above:

@@ -79,10 +79,10 @@ An explanation of the lines above:
 *  `ac_add_options --enable-optimize`: Use for release builds of SpiderMonkey.  Use `--disable-optimize` instead if building with `--enable-debug`

 *  `ac_add_options --enable-debug`: Include debugging functions, for debug builds.  Use `--disable-debug` instead if building with `--enable-optimize`

 *  `ac_add_options --disable-jemalloc`: This is absolutely needed, otherwise GJS will not build and run correctly

-*  `ac_add_options --prefix=c:/software.b/mozjs91.bin`: Some installation path, change as needed

+*  `ac_add_options --prefix=c:/software.b/mozjs102.bin`: Some installation path, change as needed

 

 If your GJS build crashes upon launch, use Dependency Walker to ensure that

-mozjs-91.dll does not depend on mozglue.dll!  If it does, or if GJS fails to

+mozjs-102.dll does not depend on mozglue.dll!  If it does, or if GJS fails to

 link with missing arena_malloc() and friends symbols, you have built SpiderMoney

 incorrectly and will need to rebuild SpiderMonkey (with the build options as

 noted above) and retry the build.

@@ -119,17 +119,17 @@ $(buildroot)/dist/include.  Note that for PDB files and .lib files,
 you will need to search for them in $(buildroot),

 where the PDB file names match the filenames for the DLLs/EXEs in

 $(buildroot)/dist/bin, and you will need to look for the following .lib files:

--mozjs-91.lib

+-mozjs-102.lib

 -js_static.lib (optional)

 

 You may want to put the .lib's and DLLs/EXEs into $(PREFIX)\lib and 

 $(PREFIX)\bin respectively, and put the headers into

-$(PREFIX)\include\mozjs-91 for convenience.

+$(PREFIX)\include\mozjs-102 for convenience.

 

-You will need to place the generated mozjs-91.pc pkg-config file into

+You will need to place the generated mozjs-102.pc pkg-config file into

 $(PREFIX)\lib\pkgconfig and ensure that pkg-config can find it by

 setting PKG_CONFIG_PATH.  Ensure that the 'includedir' and 'libdir'

-in there is correct so that the mozjs-91.pc can be used correctly in

+in there is correct so that the mozjs-102.pc can be used correctly in

 Visual Studio/clang-cl builds, and replace the `-isystem` with `-I` if

 building GJS with Visual Studio.  You will also need to ensure that the

 existing GObject-Introspection installation (if used) is on the same

diff --git a/doc/Hacking.md b/doc/Hacking.md
index 1c732f43..d58f9362 100644
--- a/doc/Hacking.md
+++ b/doc/Hacking.md
@@ -37,7 +37,7 @@ You can also skip this step if you are not writing any C++ code.)
 ## Dependencies
 
 GJS requires five other libraries to be installed: GLib, libffi,
-gobject-introspection, SpiderMonkey (also called "mozjs91" on some
+gobject-introspection, SpiderMonkey (also called "mozjs102" on some
 systems.) and the build tool Meson.
 The readline library is not required, but strongly recommended.
 We recommend installing your system's development packages for GLib,
@@ -70,15 +70,15 @@ example, Fedora 36 or Ubuntu 22.04 and later versions), then you don't
 need to build it yourself.
 Install SpiderMonkey using your system's package manager instead:
 
-<!--Ubuntu does not currently ship a build of libmozjs-91-->
+<!--Ubuntu does not currently ship a build of libmozjs-102-->
 <!-- <details>
     <summary>Ubuntu</summary>
-    <code>sudo apt-get install libmozjs-91-dev</code>
+    <code>sudo apt-get install libmozjs-102-dev</code>
 </details> -->
 
 <details>
     <summary>Fedora</summary>
-    <code>sudo dnf install mozjs91-devel</code>
+    <code>sudo dnf install mozjs102-devel</code>
 </details>
 
 If you _are_ writing C++ code, then please build SpiderMonkey yourself
@@ -86,7 +86,7 @@ with the debugging features enabled.
 This can save you time later when you submit your merge request, because
 the code will be checked using the debugging features.
 
-To build SpiderMonkey, follow the instructions on [this page](https://github.com/mozilla-spidermonkey/spidermonkey-embedding-examples/blob/esr91/docs/Building%20SpiderMonkey.md) to download the source code and build the library.
+To build SpiderMonkey, follow the instructions on [this page](https://github.com/mozilla-spidermonkey/spidermonkey-embedding-examples/blob/esr102/docs/Building%20SpiderMonkey.md) to download the source code and build the library.
 If you are using `-Dprefix` to build GJS into a different path, then
 make sure to use the same build prefix for SpiderMonkey with `--prefix`.
 
@@ -152,7 +152,7 @@ more likely to show up.
 
 To see which GC zeal options are available:
 ```sh
-JS_GC_ZEAL=-1 js91
+JS_GC_ZEAL=-1 js102
 ```
 
 We include three test setups, `extra_gc`, `pre_verify`, and
@@ -216,7 +216,7 @@ This will build GJS into a separate build directory with code coverage
 instrumentation enabled, run the test suite to collect the coverage
 data, and open the generated HTML report.
 
-[embedder](https://github.com/spidermonkey-embedders/spidermonkey-embedding-examples/blob/esr91/docs/Building%20SpiderMonkey.md)
+[embedder](https://github.com/spidermonkey-embedders/spidermonkey-embedding-examples/blob/esr102/docs/Building%20SpiderMonkey.md)
 
 ## Troubleshooting
 
diff --git a/gi/arg-cache.cpp b/gi/arg-cache.cpp
index 7c269468..ce814d6b 100644
--- a/gi/arg-cache.cpp
+++ b/gi/arg-cache.cpp
@@ -26,7 +26,7 @@
 #include <js/Utility.h>  // for UniqueChars
 #include <js/Value.h>
 #include <js/experimental/TypedData.h>
-#include <jsapi.h>        // for JS_TypeOfValue
+#include <jsapi.h>        // for InformalValueTypeName, JS_TypeOfValue
 #include <jsfriendapi.h>  // for JS_GetObjectFunction
 #include <jspubtd.h>      // for JSTYPE_FUNCTION
 
diff --git a/gi/arg.cpp b/gi/arg.cpp
index b70f2004..d70476c1 100644
--- a/gi/arg.cpp
+++ b/gi/arg.cpp
@@ -20,6 +20,7 @@
 #include <js/ErrorReport.h>  // for JS_ReportOutOfMemory
 #include <js/Exception.h>
 #include <js/GCVector.h>            // for RootedVector, MutableWrappedPtrOp...
+#include <js/PropertyAndElement.h>  // for JS_GetElement, JS_HasPropertyById
 #include <js/PropertyDescriptor.h>  // for JSPROP_ENUMERATE
 #include <js/RootingAPI.h>
 #include <js/String.h>
@@ -28,7 +29,7 @@
 #include <js/Value.h>
 #include <js/ValueArray.h>
 #include <js/experimental/TypedData.h>
-#include <jsapi.h>        // for JS_ReportOutOfMemory, JS_GetElement
+#include <jsapi.h>        // for InformalValueTypeName, IdVector
 #include <jsfriendapi.h>  // for JS_GetObjectFunction
 
 #include "gi/arg-inl.h"
diff --git a/gi/boxed.cpp b/gi/boxed.cpp
index c84cd4d4..378abb19 100644
--- a/gi/boxed.cpp
+++ b/gi/boxed.cpp
@@ -20,6 +20,7 @@
 #include <js/GCHashTable.h>  // for GCHashMap
 #include <js/GCVector.h>     // for MutableWrappedPtrOperations
 #include <js/Object.h>       // for SetReservedSlot
+#include <js/PropertyAndElement.h>  // for JS_DefineFunction, JS_Enumerate
 #include <js/String.h>
 #include <js/TracingAPI.h>
 #include <js/TypeDecls.h>
@@ -763,7 +764,6 @@ const struct JSClassOps BoxedBase::class_ops = {
     nullptr,  // mayResolve
     &BoxedBase::finalize,
     nullptr,  // call
-    nullptr,  // hasInstance
     nullptr,  // construct
     &BoxedBase::trace
 };
@@ -929,7 +929,7 @@ BoxedPrototype::BoxedPrototype(GIStructInfo* info, GType gtype)
     : GIWrapperPrototype(info, gtype),
       m_zero_args_constructor(-1),
       m_default_constructor(-1),
-      m_default_constructor_name(JSID_VOID),
+      m_default_constructor_name(JS::PropertyKey::Void()),
       m_can_allocate_directly(struct_is_simple(info)) {
     if (!m_can_allocate_directly) {
         m_can_allocate_directly_without_pointers = false;
@@ -944,8 +944,8 @@ BoxedPrototype::BoxedPrototype(GIStructInfo* info, GType gtype)
 bool BoxedPrototype::init(JSContext* context) {
     int i, n_methods;
     int first_constructor = -1;
-    jsid first_constructor_name = JSID_VOID;
-    jsid zero_args_constructor_name = JSID_VOID;
+    jsid first_constructor_name = JS::PropertyKey::Void();
+    jsid zero_args_constructor_name = JS::PropertyKey::Void();
 
     if (m_gtype != G_TYPE_NONE) {
         /* If the structure is registered as a boxed, we can create a new instance by
diff --git a/gi/closure.cpp b/gi/closure.cpp
index 288550a0..4d85a60a 100644
--- a/gi/closure.cpp
+++ b/gi/closure.cpp
@@ -8,11 +8,12 @@
 
 #include <glib.h>  // for g_assert
 
+#include <js/CallAndConstruct.h>
 #include <js/Realm.h>
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
 #include <js/ValueArray.h>
-#include <jsapi.h>  // for JS_IsExceptionPending, Call, JS_Get...
+#include <jsapi.h>  // for JS_GetFunctionObject
 
 #include "gi/closure.h"
 #include "gjs/context-private.h"
diff --git a/gi/cwrapper.cpp b/gi/cwrapper.cpp
index f5fbff8a..c6cca867 100644
--- a/gi/cwrapper.cpp
+++ b/gi/cwrapper.cpp
@@ -9,7 +9,6 @@
 #include <js/PropertyDescriptor.h>  // for JSPROP_PERMANENT
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
-#include <jsapi.h>  // for JS_DefinePropertyById
 
 #include "gi/cwrapper.h"
 #include "gi/gtype.h"
diff --git a/gi/cwrapper.h b/gi/cwrapper.h
index 159479e1..71198df0 100644
--- a/gi/cwrapper.h
+++ b/gi/cwrapper.h
@@ -16,13 +16,15 @@
 
 #include <js/CallArgs.h>
 #include <js/Class.h>
+#include <js/GlobalObject.h>  // for CurrentGlobalOrNull
 #include <js/Id.h>
 #include <js/Object.h>  // for GetClass
+#include <js/PropertyAndElement.h>
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
 #include <js/Value.h>
-#include <jsapi.h>
-#include <jspubtd.h>
+#include <jsapi.h>  // for JSFUN_CONSTRUCTOR, JS_NewPlainObject, JS_GetFuncti...
+#include <jspubtd.h>  // for JSProto_Object, JSProtoKey, JSProto_TypeError
 
 #include "gjs/jsapi-util.h"
 #include "gjs/macros.h"
@@ -84,7 +86,7 @@ class CWrapperPointerOps {
         if (!JS_InstanceOf(cx, wrapper, &Base::klass, nullptr))
             return nullptr;
 
-        return Gjs::maybe_get_private<Wrapped>(wrapper, POINTER);
+        return JS::GetMaybePtrFromReservedSlot<Wrapped>(wrapper, POINTER);
     }
 
     /*
@@ -137,7 +139,7 @@ class CWrapperPointerOps {
      * (It can return null if no private data has been set yet on the wrapper.)
      */
     [[nodiscard]] static Wrapped* for_js_nocheck(JSObject* wrapper) {
-        return Gjs::maybe_get_private<Wrapped>(wrapper, POINTER);
+        return JS::GetMaybePtrFromReservedSlot<Wrapped>(wrapper, POINTER);
     }
 
  protected:
@@ -151,7 +153,7 @@ class CWrapperPointerOps {
      * wrapper object.
      */
     [[nodiscard]] static bool has_private(JSObject* wrapper) {
-        return !!Gjs::maybe_get_private<Wrapped>(wrapper, POINTER);
+        return !!JS::GetMaybePtrFromReservedSlot<Wrapped>(wrapper, POINTER);
     }
 
     /*
@@ -202,7 +204,7 @@ class CWrapperPointerOps {
  *    class_spec's flags member.
  *  - static constexpr unsigned constructor_nargs: number of arguments that the
  *    constructor takes. If you implement constructor_impl() then also add this.
- *  - void finalize_impl(JSFreeOp*, Wrapped*): called when the JS object is
+ *  - void finalize_impl(JS::GCContext*, Wrapped*): called when the JS object is
  *    garbage collected, use this to free the C pointer and do any other cleanup
  *
  * Add optional functionality by setting members of class_spec:
@@ -289,14 +291,14 @@ class CWrapper : public CWrapperPointerOps<Base, Wrapped> {
             debug_jsprop(message, gjs_debug_id(id).c_str(), obj);
     }
 
-    static void finalize(JSFreeOp* fop, JSObject* obj) {
+    static void finalize(JS::GCContext* gcx, JSObject* obj) {
         Wrapped* priv = Base::for_js_nocheck(obj);
 
         // Call only CWrapper's original method here, not any overrides; e.g.,
         // we don't want to deal with a read barrier.
         CWrapper::debug_lifecycle(priv, obj, "Finalize");
 
-        Base::finalize_impl(fop, priv);
+        Base::finalize_impl(gcx, priv);
 
         CWrapperPointerOps<Base, Wrapped>::unset_private(obj);
     }
diff --git a/gi/enumeration.cpp b/gi/enumeration.cpp
index 62090ce4..bc0e8274 100644
--- a/gi/enumeration.cpp
+++ b/gi/enumeration.cpp
@@ -8,9 +8,10 @@
 #include <glib-object.h>
 #include <glib.h>
 
+#include <js/PropertyAndElement.h>
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
-#include <jsapi.h>  // for JS_DefineProperty, JS_NewPlainObject
+#include <jsapi.h>  // for JS_NewPlainObject
 
 #include "gi/cwrapper.h"
 #include "gi/enumeration.h"
diff --git a/gi/function.cpp b/gi/function.cpp
index af739ecd..08a0ea25 100644
--- a/gi/function.cpp
+++ b/gi/function.cpp
@@ -22,6 +22,7 @@
 #include <js/Class.h>
 #include <js/ErrorReport.h>  // for JS_ReportOutOfMemory
 #include <js/Exception.h>
+#include <js/PropertyAndElement.h>
 #include <js/PropertyDescriptor.h>  // for JSPROP_PERMANENT
 #include <js/PropertySpec.h>
 #include <js/Realm.h>  // for GetRealmFunctionPrototype
@@ -31,7 +32,7 @@
 #include <js/Value.h>
 #include <js/ValueArray.h>
 #include <js/Warnings.h>
-#include <jsapi.h>        // for HandleValueArray, JS_GetElement
+#include <jsapi.h>        // for HandleValueArray
 #include <jspubtd.h>      // for JSProtoKey
 
 #include "gi/arg-cache.h"
@@ -108,7 +109,7 @@ class Function : public CWrapper<Function> {
     GJS_JSAPI_RETURN_CONVENTION
     static bool call(JSContext* cx, unsigned argc, JS::Value* vp);
 
-    static void finalize_impl(JSFreeOp*, Function* priv);
+    static void finalize_impl(JS::GCContext*, Function* priv);
 
     GJS_JSAPI_RETURN_CONVENTION
     static bool get_length(JSContext* cx, unsigned argc, JS::Value* vp);
@@ -1153,7 +1154,7 @@ Function::~Function() {
     GJS_DEC_COUNTER(function);
 }
 
-void Function::finalize_impl(JSFreeOp*, Function* priv) {
+void Function::finalize_impl(JS::GCContext*, Function* priv) {
     if (priv == NULL)
         return; /* we are the prototype, not a real instance, so constructor never called */
     delete priv;
diff --git a/gi/fundamental.cpp b/gi/fundamental.cpp
index 56cf2dc0..d2f591e3 100644
--- a/gi/fundamental.cpp
+++ b/gi/fundamental.cpp
@@ -13,10 +13,11 @@
 #include <js/ErrorReport.h>  // for JS_ReportOutOfMemory
 #include <js/GCHashTable.h>  // for WeakCache
 #include <js/Object.h>       // for GetClass
+#include <js/PropertyAndElement.h>
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
 #include <js/Utility.h>  // for UniqueChars
-#include <jsapi.h>       // for InformalValueTypeName
+#include <jsapi.h>       // for InformalValueTypeName, JS_NewObjectWithGivenP...
 #include <mozilla/HashTable.h>
 
 #include "gi/arg-inl.h"
@@ -243,7 +244,6 @@ const struct JSClassOps FundamentalBase::class_ops = {
     nullptr,  // mayResolve
     &FundamentalBase::finalize,
     nullptr,  // call
-    nullptr,  // hasInstance
     nullptr,  // construct
     &FundamentalBase::trace
 };
diff --git a/gi/gerror.cpp b/gi/gerror.cpp
index ba70005b..91682453 100644
--- a/gi/gerror.cpp
+++ b/gi/gerror.cpp
@@ -11,17 +11,20 @@
 #include <girepository.h>
 #include <glib-object.h>
 
+#include <js/CallAndConstruct.h>
 #include <js/CallArgs.h>
 #include <js/Class.h>
 #include <js/Exception.h>
+#include <js/PropertyAndElement.h>
 #include <js/PropertyDescriptor.h>  // for JSPROP_ENUMERATE
 #include <js/RootingAPI.h>
 #include <js/SavedFrameAPI.h>
+#include <js/Stack.h>  // for BuildStackString, CaptureCurrentStack
 #include <js/TypeDecls.h>
 #include <js/Utility.h>  // for UniqueChars
 #include <js/Value.h>
 #include <js/ValueArray.h>
-#include <jsapi.h>    // for JS_DefinePropertyById, JS_GetProp...
+#include <jsapi.h>    // for InformalValueTypeName, JS_GetClassObject
 #include <jspubtd.h>  // for JSProtoKey, JSProto_Error, JSProt...
 
 #include "gi/arg-inl.h"
diff --git a/gi/gobject.cpp b/gi/gobject.cpp
index 2ab1f28b..914f6176 100644
--- a/gi/gobject.cpp
+++ b/gi/gobject.cpp
@@ -10,13 +10,15 @@
 #include <glib-object.h>
 #include <glib.h>
 
+#include <js/CallAndConstruct.h>
+#include <js/PropertyAndElement.h>
 #include <js/PropertyDescriptor.h>  // for JSPROP_READONLY
 #include <js/Realm.h>
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
 #include <js/Value.h>
 #include <js/ValueArray.h>
-#include <jsapi.h>  // for JS_SetProperty, JS_DefineProperty
+#include <jsapi.h>  // for JS_NewPlainObject
 #include <mozilla/Maybe.h>
 
 #include "gi/gobject.h"
diff --git a/gi/gtype.cpp b/gi/gtype.cpp
index 3b0b8b80..8f5bf38a 100644
--- a/gi/gtype.cpp
+++ b/gi/gtype.cpp
@@ -12,11 +12,12 @@
 #include <js/CallArgs.h>
 #include <js/Class.h>
 #include <js/GCHashTable.h>         // for WeakCache
+#include <js/PropertyAndElement.h>
 #include <js/PropertyDescriptor.h>  // for JSPROP_PERMANENT
 #include <js/PropertySpec.h>
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
-#include <jsapi.h>  // for JS_GetPropertyById, JS_AtomizeString
+#include <jsapi.h>  // for JS_NewObjectWithGivenProto
 #include <mozilla/HashTable.h>
 
 #include "gi/cwrapper.h"
@@ -47,7 +48,7 @@ class GTypeObj : public CWrapper<GTypeObj, void> {
 
     // No private data is allocated, it's stuffed directly in the private field
     // of JSObject, so nothing to free
-    static void finalize_impl(JSFreeOp*, void*) {}
+    static void finalize_impl(JS::GCContext*, void*) {}
 
     // Properties
 
diff --git a/gi/ns.cpp b/gi/ns.cpp
index 1b546c3d..3ba019ba 100644
--- a/gi/ns.cpp
+++ b/gi/ns.cpp
@@ -152,7 +152,7 @@ class Ns : private GjsAutoChar, public CWrapper<Ns> {
         return true;
     }
 
-    static void finalize_impl(JSFreeOp* fop [[maybe_unused]], Ns* priv) {
+    static void finalize_impl(JS::GCContext*, Ns* priv) {
         g_assert(priv && "Finalize called on wrong object");
         delete priv;
     }
diff --git a/gi/object.cpp b/gi/object.cpp
index 6cf97c72..3ced434f 100644
--- a/gi/object.cpp
+++ b/gi/object.cpp
@@ -22,6 +22,7 @@
 #include <glib-object.h>
 #include <glib.h>
 
+#include <js/CallAndConstruct.h>  // for IsCallable, JS_CallFunctionValue
 #include <js/CallArgs.h>
 #include <js/CharacterEncoding.h>
 #include <js/Class.h>
@@ -31,6 +32,7 @@
 #include <js/GCVector.h>            // for MutableWrappedPtrOperations
 #include <js/HeapAPI.h>
 #include <js/MemoryFunctions.h>     // for AddAssociatedMemory, RemoveAssoci...
+#include <js/PropertyAndElement.h>
 #include <js/PropertyDescriptor.h>  // for JSPROP_PERMANENT, JSPROP_READONLY
 #include <js/String.h>
 #include <js/Symbol.h>
@@ -39,8 +41,8 @@
 #include <js/Value.h>
 #include <js/ValueArray.h>
 #include <js/Warnings.h>
-#include <jsapi.h>        // for IsCallable
-#include <jsfriendapi.h>  // for JS_GetObjectFunction, IsFunctionO...
+#include <jsapi.h>        // for JS_GetFunctionObject, IdVector
+#include <jsfriendapi.h>  // for JS_GetObjectFunction, GetFunctionNativeReserved
 #include <mozilla/HashTable.h>
 
 #include "gi/arg-inl.h"
@@ -677,7 +679,7 @@ static bool interface_getter(JSContext* cx, unsigned argc, JS::Value* vp) {
         g_assert(v_override_symbol.isSymbol() &&
                  "override symbol must be a symbol");
         JS::RootedSymbol override_symbol(cx, v_override_symbol.toSymbol());
-        JS::RootedId override_id(cx, SYMBOL_TO_JSID(override_symbol));
+        JS::RootedId override_id(cx, JS::PropertyKey::Symbol(override_symbol));
 
         JS::RootedObject this_obj(cx);
         if (!args.computeThis(cx, &this_obj))
@@ -697,7 +699,7 @@ static bool interface_getter(JSContext* cx, unsigned argc, JS::Value* vp) {
     g_assert(v_prototype.isObject() && "prototype must be an object");
 
     JS::RootedObject prototype(cx, &v_prototype.toObject());
-    JS::RootedId id(cx, JS::PropertyKey::fromNonIntAtom(JS_GetFunctionId(
+    JS::RootedId id(cx, JS::PropertyKey::NonIntAtom(JS_GetFunctionId(
                             JS_GetObjectFunction(&args.callee()))));
     return JS_GetPropertyById(cx, prototype, id, args.rval());
 }
@@ -721,7 +723,7 @@ static bool interface_setter(JSContext* cx, unsigned argc, JS::Value* vp) {
     JS::RootedObject this_obj(cx);
     if (!args.computeThis(cx, &this_obj))
         return false;
-    JS::RootedId override_id(cx, SYMBOL_TO_JSID(symbol));
+    JS::RootedId override_id(cx, JS::PropertyKey::Symbol(symbol));
 
     return JS_SetPropertyById(cx, this_obj, override_id, args[0]);
 }
@@ -1582,7 +1584,7 @@ ObjectPrototype::ObjectPrototype(GIObjectInfo* info, GType gtype)
  * Private callback, called after the JS engine finishes garbage collection, and
  * notifies when weak pointers need to be either moved or swept.
  */
-void ObjectInstance::update_heap_wrapper_weak_pointers(JSContext*,
+void ObjectInstance::update_heap_wrapper_weak_pointers(JSTracer* trc,
                                                        JS::Compartment*,
                                                        void*) {
     gjs_debug_lifecycle(GJS_DEBUG_GOBJECT, "Weak pointer update callback, "
@@ -1594,15 +1596,15 @@ void ObjectInstance::update_heap_wrapper_weak_pointers(JSContext*,
     auto locked_queue = ToggleQueue::get_default();
 
     ObjectInstance::remove_wrapped_gobjects_if(
-        std::mem_fn(&ObjectInstance::weak_pointer_was_finalized),
+        [&trc](ObjectInstance* instance) -> bool {
+            return instance->weak_pointer_was_finalized(trc);
+        },
         std::mem_fn(&ObjectInstance::disassociate_js_gobject));
 
     s_wrapped_gobject_list.shrink_to_fit();
 }
 
-bool
-ObjectInstance::weak_pointer_was_finalized(void)
-{
+bool ObjectInstance::weak_pointer_was_finalized(JSTracer* trc) {
     if (has_wrapper() && !wrapper_is_rooted()) {
         bool toggle_down_queued, toggle_up_queued;
 
@@ -1613,7 +1615,7 @@ ObjectInstance::weak_pointer_was_finalized(void)
         if (!toggle_down_queued && toggle_up_queued)
             return false;
 
-        if (!update_after_gc())
+        if (!update_after_gc(trc))
             return false;
 
         if (toggle_down_queued)
@@ -1900,14 +1902,14 @@ void ObjectPrototype::trace_impl(JSTracer* tracer) {
         Gjs::Closure::for_gclosure(closure)->trace(tracer);
 }
 
-void ObjectInstance::finalize_impl(JSFreeOp* fop, JSObject* obj) {
+void ObjectInstance::finalize_impl(JS::GCContext* gcx, JSObject* obj) {
     GTypeQuery query;
     type_query_dynamic_safe(&query);
     if (G_LIKELY(query.type))
         JS::RemoveAssociatedMemory(obj, query.instance_size,
                                    MemoryUse::GObjectInstanceStruct);
 
-    GIWrapperInstance::finalize_impl(fop, obj);
+    GIWrapperInstance::finalize_impl(gcx, obj);
 }
 
 ObjectInstance::~ObjectInstance() {
@@ -2532,7 +2534,6 @@ const struct JSClassOps ObjectBase::class_ops = {
     &ObjectBase::finalize,
     NULL,
     NULL,
-    NULL,
     &ObjectBase::trace,
 };
 
diff --git a/gi/object.h b/gi/object.h
index 0985845e..e6016cb7 100644
--- a/gi/object.h
+++ b/gi/object.h
@@ -170,7 +170,7 @@ struct IdHasher {
             return js::DefaultHasher<JSString*>::hash(id.toString());
         if (id.isSymbol())
             return js::DefaultHasher<JS::Symbol*>::hash(id.toSymbol());
-        return mozilla::HashGeneric(JSID_BITS(id));
+        return mozilla::HashGeneric(id.asRawBits());
     }
     static bool match(jsid id1, jsid id2) { return id1 == id2; }
 };
@@ -333,18 +333,19 @@ class ObjectInstance : public GIWrapperInstance<ObjectBase, ObjectPrototype,
     void discard_wrapper(void) { m_wrapper.reset(); }
     void switch_to_rooted(JSContext* cx) { m_wrapper.switch_to_rooted(cx); }
     void switch_to_unrooted(JSContext* cx) { m_wrapper.switch_to_unrooted(cx); }
-    [[nodiscard]] bool update_after_gc() { return m_wrapper.update_after_gc(); }
+    [[nodiscard]] bool update_after_gc(JSTracer* trc) {
+        return m_wrapper.update_after_gc(trc);
+    }
     [[nodiscard]] bool wrapper_is_rooted() const { return m_wrapper.rooted(); }
     void release_native_object(void);
     void associate_js_gobject(JSContext* cx, JS::HandleObject obj,
                               GObject* gobj);
     void disassociate_js_gobject(void);
     void handle_context_dispose(void);
-    [[nodiscard]] bool weak_pointer_was_finalized();
+    [[nodiscard]] bool weak_pointer_was_finalized(JSTracer* trc);
     static void ensure_weak_pointer_callback(JSContext* cx);
-    static void update_heap_wrapper_weak_pointers(JSContext* cx,
-                                                  JS::Compartment* compartment,
-                                                  void* data);
+    static void update_heap_wrapper_weak_pointers(JSTracer* trc,
+                                                  JS::Compartment*, void* data);
 
  public:
     void toggle_down(void);
@@ -418,7 +419,7 @@ class ObjectInstance : public GIWrapperInstance<ObjectBase, ObjectPrototype,
     GJS_JSAPI_RETURN_CONVENTION
     bool add_property_impl(JSContext* cx, JS::HandleObject obj, JS::HandleId id,
                            JS::HandleValue value);
-    void finalize_impl(JSFreeOp* fop, JSObject* obj);
+    void finalize_impl(JS::GCContext*, JSObject* obj);
     void trace_impl(JSTracer* trc);
 
     /* JS property getters/setters */
diff --git a/gi/param.cpp b/gi/param.cpp
index 5f419db9..93fff17e 100644
--- a/gi/param.cpp
+++ b/gi/param.cpp
@@ -12,11 +12,12 @@
 #include <js/CallArgs.h>
 #include <js/Class.h>
 #include <js/Object.h>  // for GetClass
+#include <js/PropertyAndElement.h>
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
 #include <js/Utility.h>  // for UniqueChars
 #include <js/Value.h>
-#include <jsapi.h>       // for JS_GetPropertyById
+#include <jsapi.h>       // for JS_NewObjectForConstructor, JS_NewObjectWithG...
 #include <jspubtd.h>     // for JSProto_TypeError
 
 #include "gi/cwrapper.h"
@@ -47,7 +48,7 @@ struct Param : GjsAutoParam {
     if (!JS_InstanceOf(cx, obj, &gjs_param_class, nullptr))
         return nullptr;
 
-    auto* priv = Gjs::maybe_get_private<Param>(obj, POINTER);
+    auto* priv = JS::GetMaybePtrFromReservedSlot<Param>(obj, POINTER);
     return priv ? priv->get() : nullptr;
 }
 
@@ -122,8 +123,8 @@ static bool gjs_param_constructor(JSContext* cx, unsigned argc, JS::Value* vp) {
     return true;
 }
 
-static void param_finalize(JSFreeOp*, JSObject* obj) {
-    Param* priv = Gjs::maybe_get_private<Param>(obj, POINTER);
+static void param_finalize(JS::GCContext*, JSObject* obj) {
+    Param* priv = JS::GetMaybePtrFromReservedSlot<Param>(obj, POINTER);
     gjs_debug_lifecycle(GJS_DEBUG_GPARAM, "finalize, obj %p priv %p", obj,
                         priv);
     if (!priv)
diff --git a/gi/private.cpp b/gi/private.cpp
index 85001cb6..02332b18 100644
--- a/gi/private.cpp
+++ b/gi/private.cpp
@@ -12,12 +12,13 @@
 
 #include <js/Array.h>  // for JS::GetArrayLength,
 #include <js/CallArgs.h>
+#include <js/PropertyAndElement.h>
 #include <js/PropertySpec.h>
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
 #include <js/Utility.h>  // for UniqueChars
 #include <js/ValueArray.h>
-#include <jsapi.h>       // for JS_GetElement
+#include <jsapi.h>  // for JS_NewPlainObject
 
 #include "gi/gobject.h"
 #include "gi/gtype.h"
diff --git a/gi/repo.cpp b/gi/repo.cpp
index 221cf8c7..ab23677f 100644
--- a/gi/repo.cpp
+++ b/gi/repo.cpp
@@ -15,11 +15,14 @@
 #include <glib-object.h>
 #include <glib.h>
 
+#include <js/CallAndConstruct.h>  // for JS_CallFunctionValue
 #include <js/Class.h>
 #include <js/ComparisonOperators.h>
 #include <js/Exception.h>
+#include <js/GlobalObject.h>        // for CurrentGlobalOrNull
 #include <js/Id.h>                  // for PropertyKey
 #include <js/Object.h>              // for GetClass
+#include <js/PropertyAndElement.h>
 #include <js/PropertyDescriptor.h>  // for JSPROP_PERMANENT, JSPROP_RESOLVING
 #include <js/RootingAPI.h>
 #include <js/String.h>
@@ -28,7 +31,7 @@
 #include <js/Value.h>
 #include <js/ValueArray.h>
 #include <js/Warnings.h>
-#include <jsapi.h>  // for JS_DefinePropertyById, JS_GetProp...
+#include <jsapi.h>  // for JS_NewPlainObject, JS_NewObject
 
 #include "gi/arg.h"
 #include "gi/boxed.h"
diff --git a/gi/value.cpp b/gi/value.cpp
index bd2def88..d7b12bc5 100644
--- a/gi/value.cpp
+++ b/gi/value.cpp
@@ -18,6 +18,7 @@
 #include <js/Conversions.h>
 #include <js/Exception.h>
 #include <js/GCVector.h>  // for RootedVector
+#include <js/PropertyAndElement.h>
 #include <js/Realm.h>
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
diff --git a/gi/wrapperutils.h b/gi/wrapperutils.h
index 0b87f7cd..16c55f11 100644
--- a/gi/wrapperutils.h
+++ b/gi/wrapperutils.h
@@ -22,9 +22,10 @@
 #include <js/Id.h>
 #include <js/MemoryFunctions.h>
 #include <js/Object.h>
+#include <js/PropertyAndElement.h>  // for JS_DefineFunctionById
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
-#include <jsapi.h>       // for JS_GetPrototype, JS_DefineFunctionById
+#include <jsapi.h>       // for JS_GetPrototype
 #include <jspubtd.h>     // for JSProto_TypeError
 
 #include "gi/arg-inl.h"
@@ -394,7 +395,7 @@ class GIWrapperBase : public CWrapperPointerOps<Base> {
      * necessary to include a finalize_impl() function in Prototype or Instance.
      * Any needed finalization should be done in ~Prototype() and ~Instance().
      */
-    static void finalize(JSFreeOp* fop, JSObject* obj) {
+    static void finalize(JS::GCContext* gcx, JSObject* obj) {
         Base* priv = Base::for_js_nocheck(obj);
         if (!priv)
             return;  // construction didn't finish
@@ -404,9 +405,9 @@ class GIWrapperBase : public CWrapperPointerOps<Base> {
         static_cast<GIWrapperBase*>(priv)->debug_lifecycle(obj, "Finalize");
 
         if (priv->is_prototype())
-            priv->to_prototype()->finalize_impl(fop, obj);
+            priv->to_prototype()->finalize_impl(gcx, obj);
         else
-            priv->to_instance()->finalize_impl(fop, obj);
+            priv->to_instance()->finalize_impl(gcx, obj);
 
         Base::unset_private(obj);
     }
@@ -1012,7 +1013,7 @@ class GIWrapperPrototype : public Base {
     // JSClass operations
 
  protected:
-    void finalize_impl(JSFreeOp*, JSObject*) { release(); }
+    void finalize_impl(JS::GCContext*, JSObject*) { release(); }
 
     // Override if necessary
     void trace_impl(JSTracer*) {}
@@ -1107,7 +1108,7 @@ class GIWrapperInstance : public Base {
     // JSClass operations
 
  protected:
-    void finalize_impl(JSFreeOp*, JSObject*) {
+    void finalize_impl(JS::GCContext*, JSObject*) {
         delete static_cast<Instance*>(this);
     }
 
diff --git a/gjs/atoms.cpp b/gjs/atoms.cpp
index 6cb04f89..46dae144 100644
--- a/gjs/atoms.cpp
+++ b/gjs/atoms.cpp
@@ -31,7 +31,7 @@ bool GjsSymbolAtom::init(JSContext* cx, const char* str) {
     JS::Symbol* symbol = JS::NewSymbol(cx, descr);
     if (!symbol)
         return false;
-    m_jsid = JS::Heap<jsid>{SYMBOL_TO_JSID(symbol)};
+    m_jsid = JS::Heap<jsid>{JS::PropertyKey::Symbol(symbol)};
     return true;
 }
 
diff --git a/gjs/byteArray.cpp b/gjs/byteArray.cpp
index 455075fa..e0b7a03b 100644
--- a/gjs/byteArray.cpp
+++ b/gjs/byteArray.cpp
@@ -11,12 +11,13 @@
 
 #include <js/ArrayBuffer.h>
 #include <js/CallArgs.h>
+#include <js/PropertyAndElement.h>
 #include <js/PropertySpec.h>
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
 #include <js/Utility.h>   // for UniqueChars
 #include <js/experimental/TypedData.h>
-#include <jsapi.h>        // for JS_DefineFunctionById, JS_DefineFun...
+#include <jsapi.h>  // for JS_NewPlainObject
 
 #include "gi/boxed.h"
 #include "gjs/atoms.h"
diff --git a/gjs/context.cpp b/gjs/context.cpp
index a9dde93d..8bbebf84 100644
--- a/gjs/context.cpp
+++ b/gjs/context.cpp
@@ -36,6 +36,7 @@
 #endif
 
 #include <js/AllocPolicy.h>  // for SystemAllocPolicy
+#include <js/CallAndConstruct.h>  // for Call, JS_CallFunctionValue
 #include <js/CallArgs.h>     // for UndefinedHandleValue
 #include <js/CharacterEncoding.h>
 #include <js/CompilationAndEvaluation.h>
@@ -46,12 +47,15 @@
 #include <js/GCAPI.h>               // for JS_GC, JS_AddExtraGCRootsTr...
 #include <js/GCHashTable.h>         // for WeakCache
 #include <js/GCVector.h>            // for RootedVector
+#include <js/GlobalObject.h>        // for CurrentGlobalOrNull
 #include <js/Id.h>
 #include <js/Modules.h>
 #include <js/Promise.h>             // for JobQueue::SavedJobQueue
+#include <js/PropertyAndElement.h>
 #include <js/PropertyDescriptor.h>  // for JSPROP_PERMANENT, JSPROP_RE...
 #include <js/Realm.h>
 #include <js/RootingAPI.h>
+#include <js/ScriptPrivate.h>
 #include <js/SourceText.h>
 #include <js/TracingAPI.h>
 #include <js/TypeDecls.h>
@@ -59,7 +63,7 @@
 #include <js/Value.h>
 #include <js/ValueArray.h>
 #include <js/friend/DumpFunctions.h>
-#include <jsapi.h>        // for Call, CurrentGlobalOrNull
+#include <jsapi.h>        // for JS_GetFunctionObject, JS_Ge...
 #include <jsfriendapi.h>  // for ScriptEnvironmentPreparer
 #include <mozilla/UniquePtr.h>
 
diff --git a/gjs/coverage.cpp b/gjs/coverage.cpp
index 7dcc20db..487268d4 100644
--- a/gjs/coverage.cpp
+++ b/gjs/coverage.cpp
@@ -14,6 +14,7 @@
 #include <glib-object.h>
 
 #include <js/GCAPI.h>  // for JS_AddExtraGCRootsTracer, JS_Remove...
+#include <js/PropertyAndElement.h>
 #include <js/Realm.h>
 #include <js/RootingAPI.h>
 #include <js/TracingAPI.h>
@@ -21,7 +22,7 @@
 #include <js/Utility.h>  // for UniqueChars
 #include <js/Value.h>
 #include <js/experimental/CodeCoverage.h>  // for EnableCodeCoverage
-#include <jsapi.h>                         // for JS_SetPropertyById
+#include <jsapi.h>                         // for JS_WrapObject
 
 #include "gjs/atoms.h"
 #include "gjs/context-private.h"
diff --git a/gjs/debugger.cpp b/gjs/debugger.cpp
index 310fa384..43982e10 100644
--- a/gjs/debugger.cpp
+++ b/gjs/debugger.cpp
@@ -15,6 +15,7 @@
 #include <glib.h>
 
 #include <js/CallArgs.h>
+#include <js/PropertyAndElement.h>
 #include <js/PropertySpec.h>
 #include <js/Realm.h>
 #include <js/RootingAPI.h>
@@ -22,7 +23,7 @@
 #include <js/TypeDecls.h>
 #include <js/Utility.h>  // for UniqueChars
 #include <js/Value.h>
-#include <jsapi.h>  // for JS_DefineFunctions, JS_SetPropertyById
+#include <jsapi.h>  // for JS_WrapObject
 
 #include "gjs/atoms.h"
 #include "gjs/context-private.h"
diff --git a/gjs/deprecation.cpp b/gjs/deprecation.cpp
index f51e9880..c0382d59 100644
--- a/gjs/deprecation.cpp
+++ b/gjs/deprecation.cpp
@@ -16,11 +16,11 @@
 #include <js/CharacterEncoding.h>
 #include <js/Conversions.h>
 #include <js/RootingAPI.h>
+#include <js/Stack.h>  // for CaptureCurrentStack, MaxFrames
 #include <js/TypeDecls.h>
 #include <js/Utility.h>  // for UniqueChars
 #include <js/Value.h>
 #include <js/friend/DumpFunctions.h>
-#include <jsapi.h>        // for MaxFrames, CaptureCurrentStack
 
 #include "gjs/deprecation.h"
 #include "gjs/macros.h"
diff --git a/gjs/engine.cpp b/gjs/engine.cpp
index 16d84cc1..d0f05e7d 100644
--- a/gjs/engine.cpp
+++ b/gjs/engine.cpp
@@ -21,10 +21,11 @@
 #include <js/Initialization.h>  // for JS_Init, JS_ShutDown
 #include <js/Promise.h>
 #include <js/RootingAPI.h>
+#include <js/Stack.h>  // for JS_SetNativeStackQuota
 #include <js/TypeDecls.h>
 #include <js/Warnings.h>
 #include <js/experimental/SourceHook.h>
-#include <jsapi.h>  // for InitSelfHostedCode, JS_Destr...
+#include <jsapi.h>  // for JS_SetGlobalJitCompilerOption
 #include <mozilla/UniquePtr.h>
 
 #include "gjs/context-private.h"
@@ -32,7 +33,7 @@
 #include "gjs/jsapi-util.h"
 #include "util/log.h"
 
-static void gjs_finalize_callback(JSFreeOp*, JSFinalizeStatus status,
+static void gjs_finalize_callback(JS::GCContext*, JSFinalizeStatus status,
                                   void* data) {
     auto* gjs = static_cast<GjsContextPrivate*>(data);
     gjs->set_finalize_status(status);
@@ -167,12 +168,7 @@ JSContext* gjs_create_js_context(GjsContextPrivate* uninitialized_gjs) {
     if (enable_jit) {
         gjs_debug(GJS_DEBUG_CONTEXT, "Enabling JIT");
     }
-    JS::ContextOptionsRef(cx)
-        .setAsmJS(enable_jit)
-        .setTopLevelAwait(true)
-        .setClassStaticBlocks(true)
-        .setPrivateClassFields(true)
-        .setPrivateClassMethods(true);
+    JS::ContextOptionsRef(cx).setAsmJS(enable_jit);
 
     uint32_t value = enable_jit ? 1 : 0;
 
diff --git a/gjs/gjs_pch.hh b/gjs/gjs_pch.hh
index d4a820ff..f8d5c915 100644
--- a/gjs/gjs_pch.hh
+++ b/gjs/gjs_pch.hh
@@ -53,6 +53,7 @@
 #include <js/Array.h>
 #include <js/ArrayBuffer.h>
 #include <js/BigInt.h>
+#include <js/CallAndConstruct.h>
 #include <js/CallArgs.h>
 #include <js/CharacterEncoding.h>
 #include <js/Class.h>
@@ -62,12 +63,14 @@
 #include <js/Context.h>
 #include <js/ContextOptions.h>
 #include <js/Conversions.h>
+#include <js/Debug.h>
 #include <js/ErrorReport.h>
 #include <js/Exception.h>
 #include <js/GCAPI.h>
 #include <js/GCHashTable.h>
 #include <js/GCPolicyAPI.h>
 #include <js/GCVector.h>
+#include <js/GlobalObject.h>
 #include <js/HashTable.h>
 #include <js/HeapAPI.h>
 #include <js/Id.h>
@@ -79,13 +82,16 @@
 #include <js/ProfilingCategory.h>
 #include <js/ProfilingStack.h>
 #include <js/Promise.h>
+#include <js/PropertyAndElement.h>
 #include <js/PropertyDescriptor.h>
 #include <js/PropertySpec.h>
 #include <js/Realm.h>
 #include <js/RealmOptions.h>
 #include <js/RootingAPI.h>
 #include <js/SavedFrameAPI.h>
+#include <js/ScriptPrivate.h>
 #include <js/SourceText.h>
+#include <js/Stack.h>
 #include <js/String.h>
 #include <js/Symbol.h>
 #include <js/TracingAPI.h>
diff --git a/gjs/global.cpp b/gjs/global.cpp
index 9c2c91eb..84addc1b 100644
--- a/gjs/global.cpp
+++ b/gjs/global.cpp
@@ -16,9 +16,12 @@
 #include <js/Class.h>
 #include <js/CompilationAndEvaluation.h>
 #include <js/CompileOptions.h>
+#include <js/Debug.h>         // for JS_DefineDebuggerObject
+#include <js/GlobalObject.h>  // for CurrentGlobalOrNull, JS_NewGlobalObject
 #include <js/Id.h>
 #include <js/MapAndSet.h>
 #include <js/Object.h>
+#include <js/PropertyAndElement.h>
 #include <js/PropertyDescriptor.h>  // for JSPROP_PERMANENT, JSPROP_RE...
 #include <js/PropertySpec.h>
 #include <js/Realm.h>  // for GetObjectRealmOrNull, SetRealmPrivate
@@ -27,7 +30,7 @@
 #include <js/SourceText.h>
 #include <js/TypeDecls.h>
 #include <js/Utility.h>  // for UniqueChars
-#include <jsapi.h>       // for AutoSaveExceptionState, ...
+#include <jsapi.h>       // for JS_IdToValue, JS_InitReflectParse
 
 #include "gjs/atoms.h"
 #include "gjs/context-private.h"
diff --git a/gjs/importer.cpp b/gjs/importer.cpp
index 78e21e2e..0e64b5d4 100644
--- a/gjs/importer.cpp
+++ b/gjs/importer.cpp
@@ -24,8 +24,10 @@
 #include <js/ComparisonOperators.h>
 #include <js/ErrorReport.h>  // for JS_ReportOutOfMemory
 #include <js/Exception.h>
+#include <js/GlobalObject.h>  // for CurrentGlobalOrNull
 #include <js/Id.h>  // for PropertyKey
 #include <js/Object.h>  // for GetClass
+#include <js/PropertyAndElement.h>
 #include <js/PropertyDescriptor.h>
 #include <js/PropertySpec.h>
 #include <js/RootingAPI.h>
@@ -34,7 +36,7 @@
 #include <js/TypeDecls.h>
 #include <js/Utility.h>  // for UniqueChars
 #include <js/Value.h>
-#include <jsapi.h>    // for JS_DefinePropertyById, JS_DefineP...
+#include <jsapi.h>    // for JS_NewPlainObject, IdVector, JS_...
 #include <jspubtd.h>  // for JSProto_Error
 #include <mozilla/Maybe.h>
 #include <mozilla/UniquePtr.h>
@@ -172,9 +174,9 @@ define_meta_properties(JSContext       *context,
                                module_path, attrs))
         return false;
 
-    JS::RootedId to_string_tag_name(context,
-        SYMBOL_TO_JSID(JS::GetWellKnownSymbol(context,
-                                              JS::SymbolCode::toStringTag)));
+    JS::RootedId to_string_tag_name(
+        context, JS::PropertyKey::Symbol(JS::GetWellKnownSymbol(
+                     context, JS::SymbolCode::toStringTag)));
     return JS_DefinePropertyById(context, module_obj, to_string_tag_name,
                                  to_string_tag, attrs);
 }
diff --git a/gjs/internal.cpp b/gjs/internal.cpp
index 9ffe4813..414d9375 100644
--- a/gjs/internal.cpp
+++ b/gjs/internal.cpp
@@ -14,6 +14,7 @@
 #include <glib-object.h>
 #include <glib.h>
 
+#include <js/CallAndConstruct.h>  // for JS_CallFunction
 #include <js/CallArgs.h>
 #include <js/CharacterEncoding.h>
 #include <js/CompilationAndEvaluation.h>
@@ -22,6 +23,7 @@
 #include <js/GCAPI.h>  // for JS_AddExtraGCRootsTracer
 #include <js/Modules.h>
 #include <js/Promise.h>
+#include <js/PropertyAndElement.h>
 #include <js/PropertyDescriptor.h>
 #include <js/Realm.h>
 #include <js/RootingAPI.h>
@@ -32,8 +34,8 @@
 #include <js/Utility.h>  // for UniqueChars
 #include <js/Value.h>
 #include <js/ValueArray.h>
-#include <jsapi.h>  // for JS_DefinePropertyById, ...
-#include <jsfriendapi.h>
+#include <jsapi.h>        // for JS_NewPlainObject, JS_ObjectIsFunction
+#include <jsfriendapi.h>  // for JS_GetObjectFunction, SetFunctionNativeReserved
 #include <jspubtd.h>  // for JSProto_Error
 
 #include "gjs/context-private.h"
diff --git a/gjs/jsapi-dynamic-class.cpp b/gjs/jsapi-dynamic-class.cpp
index b36c0bf8..2bc4823c 100644
--- a/gjs/jsapi-dynamic-class.cpp
+++ b/gjs/jsapi-dynamic-class.cpp
@@ -9,16 +9,18 @@
 
 #include <glib.h>
 
+#include <js/CallAndConstruct.h>
 #include <js/CallArgs.h>  // for JSNative
 #include <js/Class.h>
 #include <js/ComparisonOperators.h>
 #include <js/Object.h>              // for GetClass
+#include <js/PropertyAndElement.h>  // for JS_DefineFunctions, JS_DefinePro...
 #include <js/Realm.h>  // for GetRealmObjectPrototype
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
 #include <js/Value.h>
 #include <js/ValueArray.h>
-#include <jsapi.h>        // for JS_DefineFunctions, JS_DefineProp...
+#include <jsapi.h>        // for JS_GetFunctionObject, JS_GetPrototype
 #include <jsfriendapi.h>  // for GetFunctionNativeReserved, NewFun...
 #include <jspubtd.h>      // for JSProto_TypeError
 
diff --git a/gjs/jsapi-util-error.cpp b/gjs/jsapi-util-error.cpp
index c003904b..80074333 100644
--- a/gjs/jsapi-util-error.cpp
+++ b/gjs/jsapi-util-error.cpp
@@ -9,17 +9,20 @@
 #include <glib.h>
 
 #include <js/AllocPolicy.h>
+#include <js/CallAndConstruct.h>
 #include <js/CharacterEncoding.h>
 #include <js/ErrorReport.h>
 #include <js/Exception.h>
 #include <js/GCHashTable.h>  // for GCHashSet
 #include <js/HashTable.h>    // for DefaultHasher
+#include <js/PropertyAndElement.h>
 #include <js/RootingAPI.h>
+#include <js/Stack.h>  // for BuildStackString
 #include <js/TypeDecls.h>
 #include <js/Utility.h>  // for UniqueChars
 #include <js/ValueArray.h>
-#include <jsapi.h>       // for BuildStackString, Construct, JS_GetClassObject
-#include <jspubtd.h>     // for JSProtoKey, JSProto_Error, JSProto...
+#include <jsapi.h>              // for JS_GetClassObject
+#include <jspubtd.h>            // for JSProtoKey, JSProto_Error, JSProto...
 #include <mozilla/HashTable.h>  // for HashSet<>::AddPtr
 
 #include "gjs/atoms.h"
diff --git a/gjs/jsapi-util-root.h b/gjs/jsapi-util-root.h
index 7f4e2749..80f4d875 100644
--- a/gjs/jsapi-util-root.h
+++ b/gjs/jsapi-util-root.h
@@ -62,8 +62,9 @@ struct GjsHeapOperation {
 
 template<>
 struct GjsHeapOperation<JSObject *> {
-    [[nodiscard]] static bool update_after_gc(JS::Heap<JSObject*>* location) {
-        JS_UpdateWeakPointerAfterGC(location);
+    [[nodiscard]] static bool update_after_gc(JSTracer* trc,
+                                              JS::Heap<JSObject*>* location) {
+        JS_UpdateWeakPointerAfterGC(trc, location);
         return (location->unbarrieredGet() == nullptr);
     }
 
@@ -178,7 +179,7 @@ class GjsMaybeOwned {
     void root(JSContext* cx, const T& thing) {
         debug("root()");
         g_assert(!m_root);
-        g_assert(m_heap.get() == JS::SafelyInitialized<T>());
+        g_assert(m_heap.get() == JS::SafelyInitialized<T>::create());
         m_heap.~Heap();
         m_root = std::make_unique<JS::PersistentRooted<T>>(cx, thing);
     }
@@ -204,7 +205,7 @@ class GjsMaybeOwned {
     void reset() {
         debug("reset()");
         if (!m_root) {
-            m_heap = JS::SafelyInitialized<T>();
+            m_heap = JS::SafelyInitialized<T>::create();
             return;
         }
 
@@ -251,10 +252,10 @@ class GjsMaybeOwned {
     /* If not tracing, then you must call this method during GC in order to
      * update the object's location if it was moved, or null it out if it was
      * finalized. If the object was finalized, returns true. */
-    bool update_after_gc() {
+    bool update_after_gc(JSTracer* trc) {
         debug("update_after_gc()");
         g_assert(!m_root);
-        return GjsHeapOperation<T>::update_after_gc(&m_heap);
+        return GjsHeapOperation<T>::update_after_gc(trc, &m_heap);
     }
 
     [[nodiscard]] constexpr bool rooted() const { return m_root != nullptr; }
diff --git a/gjs/jsapi-util-string.cpp b/gjs/jsapi-util-string.cpp
index 29e56c9e..fcef285f 100644
--- a/gjs/jsapi-util-string.cpp
+++ b/gjs/jsapi-util-string.cpp
@@ -438,7 +438,7 @@ bool gjs_get_string_id(JSContext* cx, jsid id, JS::UniqueChars* name_p) {
         return true;
     }
 
-    JSLinearString* lstr = JSID_TO_LINEAR_STRING(id);
+    JSLinearString* lstr = id.toLinearString();
     JS::RootedString s(cx, JS_FORGET_STRING_LINEARNESS(lstr));
     *name_p = JS_EncodeStringToUTF8(cx, s);
     return !!*name_p;
@@ -475,7 +475,7 @@ gjs_intern_string_to_id(JSContext  *cx,
 {
     JS::RootedString str(cx, JS_AtomizeAndPinString(cx, string));
     if (!str)
-        return JSID_VOID;
+        return JS::PropertyKey::Void();
     return JS::PropertyKey::fromPinnedString(str);
 }
 
@@ -662,6 +662,6 @@ std::string
 gjs_debug_id(jsid id)
 {
     if (id.isString())
-        return gjs_debug_linear_string(JSID_TO_LINEAR_STRING(id), NoQuotes);
+        return gjs_debug_linear_string(id.toLinearString(), NoQuotes);
     return gjs_debug_value(js::IdToValue(id));
 }
diff --git a/gjs/jsapi-util.cpp b/gjs/jsapi-util.cpp
index 3acb6642..7dc86fe8 100644
--- a/gjs/jsapi-util.cpp
+++ b/gjs/jsapi-util.cpp
@@ -30,12 +30,14 @@
 #include <js/GCVector.h>  // for RootedVector
 #include <js/HashTable.h>  // for DefaultHasher
 #include <js/Object.h>    // for GetClass
+#include <js/PropertyAndElement.h>
 #include <js/RootingAPI.h>
+#include <js/Stack.h>  // for BuildStackString
 #include <js/String.h>
 #include <js/TypeDecls.h>
 #include <js/Value.h>
 #include <js/ValueArray.h>
-#include <jsapi.h>        // for JS_GetPropertyById, JS_InstanceOf
+#include <jsapi.h>        // for JS_InstanceOf
 #include <jsfriendapi.h>  // for ProtoKeyToClass
 #include <mozilla/HashTable.h>  // for HashSet::AddPtr
 
diff --git a/gjs/jsapi-util.h b/gjs/jsapi-util.h
index a891fa42..0724181e 100644
--- a/gjs/jsapi-util.h
+++ b/gjs/jsapi-util.h
@@ -26,10 +26,8 @@
 #include <js/GCAPI.h>
 #include <js/GCPolicyAPI.h>  // for IgnoreGCPolicy
 #include <js/Id.h>
-#include <js/Object.h>  // for GetReservedSlot
 #include <js/TypeDecls.h>
 #include <js/Utility.h>  // for UniqueChars
-#include <js/Value.h>
 #include <jspubtd.h>     // for JSProtoKey
 
 #include "gjs/macros.h"
@@ -636,18 +634,6 @@ template <typename T>
     return true;
 }
 
-/**
- * Helper function, backported from future SpiderMonkey's
- * JS::GetMaybePtrFromReservedSlot(), to get the pointer value (or nullptr if
- * not set) from an object's reserved slot. The slot must contain either a
- * JS::PrivateValue(T*) or JS::UndefinedValue.
- */
-template <typename T>
-inline T* maybe_get_private(JSObject* obj, size_t slot) {
-    JS::Value v = JS::GetReservedSlot(obj, slot);
-    return v.isUndefined() ? nullptr : static_cast<T*>(v.toPrivate());
-}
-
 }  // namespace Gjs
 
 [[nodiscard]] const char* gjs_explain_gc_reason(JS::GCReason reason);
diff --git a/gjs/module.cpp b/gjs/module.cpp
index c8d4b21c..c0422caf 100644
--- a/gjs/module.cpp
+++ b/gjs/module.cpp
@@ -12,6 +12,7 @@
 #include <gio/gio.h>
 #include <glib.h>
 
+#include <js/CallAndConstruct.h>
 #include <js/CallArgs.h>
 #include <js/CharacterEncoding.h>  // for ConstUTF8CharsZ
 #include <js/Class.h>
@@ -21,21 +22,24 @@
 #include <js/ErrorReport.h>  // for JS_ReportOutOfMemory
 #include <js/Exception.h>
 #include <js/GCVector.h>  // for RootedVector
+#include <js/GlobalObject.h>  // for CurrentGlobalOrNull
 #include <js/Id.h>
 #include <js/Modules.h>
 #include <js/Object.h>
 #include <js/Promise.h>
+#include <js/PropertyAndElement.h>
 #include <js/PropertyDescriptor.h>
 #include <js/Realm.h>
 #include <js/RootingAPI.h>
+#include <js/ScriptPrivate.h>
 #include <js/SourceText.h>
 #include <js/String.h>
 #include <js/TypeDecls.h>
 #include <js/Utility.h>  // for UniqueChars
 #include <js/Value.h>
 #include <js/ValueArray.h>
-#include <jsapi.h>  // for JS_DefinePropertyById, ...
-#include <jsfriendapi.h>  // for SetFunctionNativeReserved
+#include <jsapi.h>        // for JS_GetFunctionObject, JS_Ne...
+#include <jsfriendapi.h>  // for NewFunctionWithReserved
 #include <mozilla/Maybe.h>
 
 #include "gjs/atoms.h"
@@ -76,7 +80,7 @@ class GjsScriptModule {
     /* Private data accessors */
 
     [[nodiscard]] static inline GjsScriptModule* priv(JSObject* module) {
-        return Gjs::maybe_get_private<GjsScriptModule>(
+        return JS::GetMaybePtrFromReservedSlot<GjsScriptModule>(
             module, GjsScriptModule::POINTER);
     }
 
@@ -216,7 +220,9 @@ class GjsScriptModule {
         return priv(module)->resolve_impl(cx, module, id, resolved);
     }
 
-    static void finalize(JSFreeOp*, JSObject* module) { delete priv(module); }
+    static void finalize(JS::GCContext*, JSObject* module) {
+        delete priv(module);
+    }
 
     static constexpr JSClassOps class_ops = {
         nullptr,  // addProperty
diff --git a/gjs/promise.cpp b/gjs/promise.cpp
index 0ce4bd7c..74127960 100644
--- a/gjs/promise.cpp
+++ b/gjs/promise.cpp
@@ -10,10 +10,11 @@
 #include <glib-object.h>
 
 #include <js/CallArgs.h>
+#include <js/PropertyAndElement.h>  // for JS_DefineFunctions
 #include <js/PropertySpec.h>
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
-#include <jsapi.h>  // for JS_DefineFunctions, JS_NewPlainObject
+#include <jsapi.h>  // for JS_NewPlainObject
 
 #include "gjs/context-private.h"
 #include "gjs/jsapi-util.h"
diff --git a/gjs/text-encoding.cpp b/gjs/text-encoding.cpp
index e9010023..95a6f86c 100644
--- a/gjs/text-encoding.cpp
+++ b/gjs/text-encoding.cpp
@@ -26,6 +26,7 @@
 #include <js/ErrorReport.h>  // for JS_ReportOutOfMemory
 #include <js/Exception.h>    // for JS_ClearPendingException, JS_...
 #include <js/GCAPI.h>  // for AutoCheckCannotGC
+#include <js/PropertyAndElement.h>
 #include <js/PropertySpec.h>
 #include <js/RootingAPI.h>
 #include <js/String.h>
@@ -33,7 +34,7 @@
 #include <js/Utility.h>  // for UniqueChars
 #include <js/Value.h>
 #include <js/experimental/TypedData.h>
-#include <jsapi.h>        // for JS_DefineFunctionById, JS_DefineFun...
+#include <jsapi.h>        // for JS_NewPlainObject, JS_InstanceOf
 #include <jsfriendapi.h>  // for ProtoKeyToClass
 #include <jspubtd.h>      // for JSProto_TypeError, JSProto_InternalError
 #include <mozilla/Maybe.h>
diff --git a/meson.build b/meson.build
index add390ec..55356a9c 100644
--- a/meson.build
+++ b/meson.build
@@ -127,7 +127,7 @@ gio = dependency('gio-2.0', version: glib_required_version,
 ffi = dependency('libffi', fallback: ['libffi', 'ffi_dep'])
 gi = dependency('gobject-introspection-1.0', version: '>= 1.66.0',
     fallback: ['gobject-introspection', 'girepo_dep'])
-spidermonkey = dependency('mozjs-91', version: '>= 91.3.0')
+spidermonkey = dependency('mozjs-102')
 
 # We might need to look for the headers and lib's for Cairo
 # manually on MSVC/clang-cl builds...
diff --git a/modules/cairo-context.cpp b/modules/cairo-context.cpp
index 356ba456..b777fb29 100644
--- a/modules/cairo-context.cpp
+++ b/modules/cairo-context.cpp
@@ -13,13 +13,14 @@
 #include <js/Array.h>  // for JS::NewArrayObject
 #include <js/CallArgs.h>
 #include <js/Conversions.h>
+#include <js/PropertyAndElement.h>
 #include <js/PropertyDescriptor.h>  // for JSPROP_READONLY
 #include <js/PropertySpec.h>
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
 #include <js/Utility.h>  // for UniqueChars
 #include <js/Value.h>
-#include <jsapi.h>  // for JS_SetElement
+#include <jsapi.h>  // for JS_NewPlainObject
 
 #include "gi/arg-inl.h"
 #include "gi/arg.h"
@@ -260,7 +261,7 @@ cairo_t* CairoContext::constructor_impl(JSContext* context,
     return cr;
 }
 
-void CairoContext::finalize_impl(JSFreeOp*, cairo_t* cr) {
+void CairoContext::finalize_impl(JS::GCContext*, cairo_t* cr) {
     if (!cr)
         return;
     cairo_destroy(cr);
diff --git a/modules/cairo-path.cpp b/modules/cairo-path.cpp
index 415fcf2e..b6b0726c 100644
--- a/modules/cairo-path.cpp
+++ b/modules/cairo-path.cpp
@@ -11,7 +11,7 @@
 #include <js/PropertySpec.h>
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
-#include <jsapi.h>
+#include <jsapi.h>  // for JS_NewObjectWithGivenProto
 
 #include "modules/cairo-private.h"
 
@@ -43,7 +43,7 @@ JSObject* CairoPath::take_c_ptr(JSContext* cx, cairo_path_t* ptr) {
     return wrapper;
 }
 
-void CairoPath::finalize_impl(JSFreeOp*, cairo_path_t* path) {
+void CairoPath::finalize_impl(JS::GCContext*, cairo_path_t* path) {
     if (!path)
         return;
     cairo_path_destroy(path);
diff --git a/modules/cairo-pattern.cpp b/modules/cairo-pattern.cpp
index a9254184..9e7e3692 100644
--- a/modules/cairo-pattern.cpp
+++ b/modules/cairo-pattern.cpp
@@ -65,14 +65,13 @@ const JSFunctionSpec CairoPattern::proto_funcs[] = {
 
 /**
  * CairoPattern::finalize_impl:
- * @fop: the free op
  * @pattern: pointer to free
  *
  * Destroys the resources associated with a pattern wrapper.
  *
  * This is mainly used for subclasses.
  */
-void CairoPattern::finalize_impl(JSFreeOp*, cairo_pattern_t* pattern) {
+void CairoPattern::finalize_impl(JS::GCContext*, cairo_pattern_t* pattern) {
     if (!pattern)
         return;
     cairo_pattern_destroy(pattern);
@@ -137,6 +136,6 @@ cairo_pattern_t* CairoPattern::for_js(JSContext* cx,
         return nullptr;
     }
 
-    return Gjs::maybe_get_private<cairo_pattern_t>(pattern_wrapper,
-                                                   CairoPattern::POINTER);
+    return JS::GetMaybePtrFromReservedSlot<cairo_pattern_t>(
+        pattern_wrapper, CairoPattern::POINTER);
 }
diff --git a/modules/cairo-private.h b/modules/cairo-private.h
index 8e17c83e..75d111c5 100644
--- a/modules/cairo-private.h
+++ b/modules/cairo-private.h
@@ -55,7 +55,7 @@ class CairoRegion : public CWrapper<CairoRegion, cairo_region_t> {
     static cairo_region_t* constructor_impl(JSContext* cx,
                                             const JS::CallArgs& args);
 
-    static void finalize_impl(JSFreeOp* fop, cairo_region_t* cr);
+    static void finalize_impl(JS::GCContext*, cairo_region_t* cr);
 
     static const JSFunctionSpec proto_funcs[];
     static const JSPropertySpec proto_props[];
@@ -95,7 +95,7 @@ class CairoContext : public CWrapper<CairoContext, cairo_t> {
     GJS_JSAPI_RETURN_CONVENTION
     static cairo_t* constructor_impl(JSContext* cx, const JS::CallArgs& args);
 
-    static void finalize_impl(JSFreeOp* fop, cairo_t* cr);
+    static void finalize_impl(JS::GCContext*, cairo_t* cr);
 
     static const JSFunctionSpec proto_funcs[];
     static const JSPropertySpec proto_props[];
@@ -133,7 +133,7 @@ class CairoPath : public CWrapper<CairoPath, cairo_path_t> {
         GjsGlobalSlot::PROTOTYPE_cairo_path;
     static constexpr GjsDebugTopic DEBUG_TOPIC = GJS_DEBUG_CAIRO;
 
-    static void finalize_impl(JSFreeOp* fop, cairo_path_t* path);
+    static void finalize_impl(JS::GCContext*, cairo_path_t* path);
 
     static const JSPropertySpec proto_props[];
     static constexpr js::ClassSpec class_spec = {
@@ -174,7 +174,7 @@ class CairoSurface : public CWrapper<CairoSurface, cairo_surface_t> {
 
     static GType gtype() { return CAIRO_GOBJECT_TYPE_SURFACE; }
 
-    static void finalize_impl(JSFreeOp* fop, cairo_surface_t* surface);
+    static void finalize_impl(JS::GCContext*, cairo_surface_t* surface);
 
     static const JSFunctionSpec proto_funcs[];
     static const JSPropertySpec proto_props[];
@@ -240,7 +240,7 @@ class CairoImageSurface : public CWrapper<CairoImageSurface, cairo_surface_t> {
         return cairo_surface_reference(surface);
     }
 
-    static void finalize_impl(JSFreeOp*, cairo_surface_t*) {}
+    static void finalize_impl(JS::GCContext*, cairo_surface_t*) {}
 
     GJS_JSAPI_RETURN_CONVENTION
     static cairo_surface_t* constructor_impl(JSContext* cx,
@@ -280,7 +280,7 @@ class CairoPSSurface : public CWrapper<CairoPSSurface, cairo_surface_t> {
         return cairo_surface_reference(surface);
     }
 
-    static void finalize_impl(JSFreeOp*, cairo_surface_t*) {}
+    static void finalize_impl(JS::GCContext*, cairo_surface_t*) {}
 
     GJS_JSAPI_RETURN_CONVENTION
     static cairo_surface_t* constructor_impl(JSContext* cx,
@@ -326,7 +326,7 @@ class CairoPDFSurface : public CWrapper<CairoPDFSurface, cairo_surface_t> {
         return cairo_surface_reference(surface);
     }
 
-    static void finalize_impl(JSFreeOp*, cairo_surface_t*) {}
+    static void finalize_impl(JS::GCContext*, cairo_surface_t*) {}
 
     GJS_JSAPI_RETURN_CONVENTION
     static cairo_surface_t* constructor_impl(JSContext* cx,
@@ -372,7 +372,7 @@ class CairoSVGSurface : public CWrapper<CairoSVGSurface, cairo_surface_t> {
         return cairo_surface_reference(surface);
     }
 
-    static void finalize_impl(JSFreeOp*, cairo_surface_t*) {}
+    static void finalize_impl(JS::GCContext*, cairo_surface_t*) {}
 
     GJS_JSAPI_RETURN_CONVENTION
     static cairo_surface_t* constructor_impl(JSContext* cx,
@@ -430,7 +430,7 @@ class CairoPattern : public CWrapper<CairoPattern, cairo_pattern_t> {
     static bool getType_func(JSContext* context, unsigned argc, JS::Value* vp);
 
  protected:
-    static void finalize_impl(JSFreeOp* fop, cairo_pattern_t* pattern);
+    static void finalize_impl(JS::GCContext*, cairo_pattern_t* pattern);
 
  public:
     static cairo_pattern_t* for_js(JSContext* cx,
@@ -469,7 +469,7 @@ class CairoGradient : public CWrapper<CairoGradient, cairo_pattern_t> {
         "Gradient", JSCLASS_HAS_RESERVED_SLOTS(1) | JSCLASS_BACKGROUND_FINALIZE,
         &CairoPattern::class_ops, &CairoGradient::class_spec};
 
-    static void finalize_impl(JSFreeOp*, cairo_pattern_t*) {}
+    static void finalize_impl(JS::GCContext*, cairo_pattern_t*) {}
 };
 
 class CairoLinearGradient
@@ -509,7 +509,7 @@ class CairoLinearGradient
     static cairo_pattern_t* constructor_impl(JSContext* cx,
                                              const JS::CallArgs& args);
 
-    static void finalize_impl(JSFreeOp*, cairo_pattern_t*) {}
+    static void finalize_impl(JS::GCContext*, cairo_pattern_t*) {}
 };
 
 class CairoRadialGradient
@@ -549,7 +549,7 @@ class CairoRadialGradient
     static cairo_pattern_t* constructor_impl(JSContext* cx,
                                              const JS::CallArgs& args);
 
-    static void finalize_impl(JSFreeOp*, cairo_pattern_t*) {}
+    static void finalize_impl(JS::GCContext*, cairo_pattern_t*) {}
 };
 
 class CairoSurfacePattern
@@ -589,7 +589,7 @@ class CairoSurfacePattern
     static cairo_pattern_t* constructor_impl(JSContext* cx,
                                              const JS::CallArgs& args);
 
-    static void finalize_impl(JSFreeOp*, cairo_pattern_t*) {}
+    static void finalize_impl(JS::GCContext*, cairo_pattern_t*) {}
 };
 
 class CairoSolidPattern : public CWrapper<CairoSolidPattern, cairo_pattern_t> {
@@ -623,7 +623,7 @@ class CairoSolidPattern : public CWrapper<CairoSolidPattern, cairo_pattern_t> {
         return cairo_pattern_reference(pattern);
     }
 
-    static void finalize_impl(JSFreeOp*, cairo_pattern_t*) {}
+    static void finalize_impl(JS::GCContext*, cairo_pattern_t*) {}
 };
 
 #endif  // MODULES_CAIRO_PRIVATE_H_
diff --git a/modules/cairo-region.cpp b/modules/cairo-region.cpp
index a6333f77..2490dabc 100644
--- a/modules/cairo-region.cpp
+++ b/modules/cairo-region.cpp
@@ -9,12 +9,13 @@
 
 #include <js/CallArgs.h>
 #include <js/Conversions.h>
+#include <js/PropertyAndElement.h>
 #include <js/PropertyDescriptor.h>  // for JSPROP_READONLY
 #include <js/PropertySpec.h>
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
 #include <js/Value.h>
-#include <jsapi.h>  // for JS_GetPropertyById, JS_SetPropert...
+#include <jsapi.h>  // for JS_NewPlainObject
 
 #include "gi/arg-inl.h"
 #include "gi/arg.h"
@@ -219,7 +220,7 @@ cairo_region_t* CairoRegion::constructor_impl(JSContext* context,
     return cairo_region_create();
 }
 
-void CairoRegion::finalize_impl(JSFreeOp*, cairo_region_t* region) {
+void CairoRegion::finalize_impl(JS::GCContext*, cairo_region_t* region) {
     if (!region)
         return;
 
diff --git a/modules/cairo-surface.cpp b/modules/cairo-surface.cpp
index 51661c3c..87718643 100644
--- a/modules/cairo-surface.cpp
+++ b/modules/cairo-surface.cpp
@@ -207,14 +207,13 @@ const JSFunctionSpec CairoSurface::proto_funcs[] = {
 
 /**
  * CairoSurface::finalize_impl:
- * @fop: the free op
  * @surface: the pointer to finalize
  *
  * Destroys the resources associated with a surface wrapper.
  *
  * This is mainly used for subclasses.
  */
-void CairoSurface::finalize_impl(JSFreeOp*, cairo_surface_t* surface) {
+void CairoSurface::finalize_impl(JS::GCContext*, cairo_surface_t* surface) {
     if (!surface)
         return;
     cairo_surface_destroy(surface);
@@ -272,8 +271,8 @@ cairo_surface_t* CairoSurface::for_js(JSContext* cx,
         return nullptr;
     }
 
-    return Gjs::maybe_get_private<cairo_surface_t>(surface_wrapper,
-                                                   CairoSurface::POINTER);
+    return JS::GetMaybePtrFromReservedSlot<cairo_surface_t>(
+        surface_wrapper, CairoSurface::POINTER);
 }
 
 [[nodiscard]] static bool surface_to_g_argument(
diff --git a/modules/console.cpp b/modules/console.cpp
index 33c189f9..228ee413 100644
--- a/modules/console.cpp
+++ b/modules/console.cpp
@@ -27,12 +27,14 @@
 #include <glib.h>
 #include <glib/gprintf.h>  // for g_fprintf
 
+#include <js/CallAndConstruct.h>
 #include <js/CallArgs.h>
 #include <js/CharacterEncoding.h>  // for JS_EncodeStringToUTF8
 #include <js/CompilationAndEvaluation.h>
 #include <js/CompileOptions.h>
 #include <js/ErrorReport.h>
 #include <js/Exception.h>
+#include <js/PropertyAndElement.h>
 #include <js/RootingAPI.h>
 #include <js/SourceText.h>
 #include <js/TypeDecls.h>
@@ -40,7 +42,7 @@
 #include <js/Value.h>
 #include <js/ValueArray.h>
 #include <js/Warnings.h>
-#include <jsapi.h>  // for JS_IsExceptionPending, Exce...
+#include <jsapi.h>  // for JS_NewPlainObject
 
 #include "gjs/atoms.h"
 #include "gjs/context-private.h"
diff --git a/modules/print.cpp b/modules/print.cpp
index e483446c..7e0504f8 100644
--- a/modules/print.cpp
+++ b/modules/print.cpp
@@ -13,12 +13,13 @@
 #include <js/CharacterEncoding.h>  // for JS_EncodeStringToUTF8
 #include <js/Conversions.h>
 #include <js/Exception.h>
+#include <js/PropertyAndElement.h>  // for JS_DefineFunctions
 #include <js/PropertySpec.h>  // for JS_FN, JSFunctionSpec, JS_FS_END
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
 #include <js/Utility.h>  // for UniqueChars
 #include <js/Value.h>
-#include <jsapi.h>
+#include <jsapi.h>  // for JS_NewPlainObject
 
 #include "gjs/global.h"
 #include "gjs/jsapi-util.h"
diff --git a/modules/system.cpp b/modules/system.cpp
index 0f441096..9c43830e 100644
--- a/modules/system.cpp
+++ b/modules/system.cpp
@@ -18,13 +18,14 @@
 #include <js/Date.h>                // for ResetTimeZone
 #include <js/GCAPI.h>               // for JS_GC
 #include <js/JSON.h>
+#include <js/PropertyAndElement.h>
 #include <js/PropertyDescriptor.h>  // for JSPROP_READONLY
 #include <js/PropertySpec.h>
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
 #include <js/Value.h>     // for NullValue
 #include <js/friend/DumpFunctions.h>
-#include <jsapi.h>        // for JS_DefinePropertyById, JS_DefineF...
+#include <jsapi.h>        // for JS_GetFunctionObject, JS_NewPlainObject
 #include <jsfriendapi.h>  // for GetFunctionNativeReserved, NewFunctionByIdW...
 
 #include "gi/object.h"
diff --git a/test/gjs-test-call-args.cpp b/test/gjs-test-call-args.cpp
index fccd9c22..15454d2d 100644
--- a/test/gjs-test-call-args.cpp
+++ b/test/gjs-test-call-args.cpp
@@ -11,13 +11,13 @@
 #include <js/CallArgs.h>
 #include <js/CompilationAndEvaluation.h>
 #include <js/CompileOptions.h>
+#include <js/PropertyAndElement.h>
 #include <js/PropertySpec.h>
 #include <js/RootingAPI.h>
 #include <js/SourceText.h>
 #include <js/String.h>
 #include <js/TypeDecls.h>
 #include <js/Utility.h>  // for UniqueChars
-#include <jsapi.h>       // for JS_DefineFunctions
 
 #include "gjs/jsapi-util-args.h"
 #include "gjs/jsapi-util.h"
diff --git a/test/gjs-test-rooting.cpp b/test/gjs-test-rooting.cpp
index 077f4508..7a96ba1e 100644
--- a/test/gjs-test-rooting.cpp
+++ b/test/gjs-test-rooting.cpp
@@ -16,9 +16,10 @@
 
 #include "gjs/context-private.h"
 #include "gjs/jsapi-util-root.h"
-#include "gjs/jsapi-util.h"  // for maybe_get_private
 #include "test/gjs-test-utils.h"
 
+class JSTracer;
+
 // COMPAT: https://gitlab.gnome.org/GNOME/glib/-/merge_requests/1553
 #ifdef __clang_analyzer__
 void g_assertion_message(const char*, const char*, int, const char*,
@@ -42,8 +43,8 @@ struct GjsRootingFixture {
     GjsMaybeOwned<JSObject *> *obj;  /* only used in callback test cases */
 };
 
-static void test_obj_finalize(JSFreeOp*, JSObject* obj) {
-    bool* finalized_p = Gjs::maybe_get_private<bool>(obj, POINTER);
+static void test_obj_finalize(JS::GCContext*, JSObject* obj) {
+    bool* finalized_p = JS::GetMaybePtrFromReservedSlot<bool>(obj, POINTER);
     g_assert_false(*finalized_p);
     *finalized_p = true;
 }
@@ -148,10 +149,10 @@ static void test_maybe_owned_rooted_is_collected_after_reset(
     delete obj;
 }
 
-static void update_weak_pointer(JSContext*, JS::Compartment*, void* data) {
+static void update_weak_pointer(JSTracer* trc, JS::Compartment*, void* data) {
     auto* obj = static_cast<GjsMaybeOwned<JSObject*>*>(data);
     if (*obj)
-        obj->update_after_gc();
+        obj->update_after_gc(trc);
 }
 
 static void test_maybe_owned_weak_pointer_is_collected_by_gc(
diff --git a/test/gjs-tests.cpp b/test/gjs-tests.cpp
index ecf986fb..49011bba 100644
--- a/test/gjs-tests.cpp
+++ b/test/gjs-tests.cpp
@@ -21,12 +21,13 @@
 #include <js/CharacterEncoding.h>
 #include <js/Exception.h>
 #include <js/Id.h>
+#include <js/PropertyAndElement.h>
 #include <js/RootingAPI.h>
 #include <js/String.h>
 #include <js/TypeDecls.h>
 #include <js/Utility.h>  // for UniqueChars
 #include <js/Value.h>
-#include <jsapi.h>
+#include <jsapi.h>    // for JS_GetClassObject
 #include <jspubtd.h>  // for JSProto_Number
 #include <mozilla/Span.h>  // for MakeStringSpan
 
diff --git a/tools/process_iwyu.py b/tools/process_iwyu.py
index 6699f4ec..8b70517c 100755
--- a/tools/process_iwyu.py
+++ b/tools/process_iwyu.py
@@ -40,12 +40,12 @@ FWD_DECLS_IN_HEADER = (
     'struct JSContext;',
     'struct JSClass;',
     'class JSFunction;',
-    'class JSFreeOp;',
     'class JSObject;',
     'struct JSRuntime;',
     'class JSScript;',
     'class JSString;',
     'namespace js { class TempAllocPolicy; }',
+    'namespace JS { class GCContext; }',
     'namespace JS { struct PropertyKey; }',
     'namespace JS { class Symbol; }',
     'namespace JS { class BigInt; }',
diff --git a/tools/run_iwyu.sh b/tools/run_iwyu.sh
index 047281c0..2b7b87be 100755
--- a/tools/run_iwyu.sh
+++ b/tools/run_iwyu.sh
@@ -47,7 +47,7 @@ IWYU="python3 $(which iwyu_tool || which iwyu-tool || which iwyu_tool.py) -p ."
 IWYU_TOOL_ARGS="-I../gjs"
 IWYU_ARGS="-Wno-pragma-once-outside-header"
 IWYU_RAW="include-what-you-use -xc++ -std=c++17 -Xiwyu --keep=config.h $IWYU_ARGS"
-IWYU_RAW_INC="-I. -I.. $(pkg-config --cflags gobject-introspection-1.0 mozjs-91)"
+IWYU_RAW_INC="-I. -I.. $(pkg-config --cflags gobject-introspection-1.0 mozjs-102)"
 PRIVATE_MAPPING="-Xiwyu --mapping_file=$SRCDIR/tools/gjs-private-iwyu.imp -Xiwyu --keep=config.h"
 PUBLIC_MAPPING="-Xiwyu --mapping_file=$SRCDIR/tools/gjs-public-iwyu.imp"
 POSTPROCESS="python3 $SRCDIR/tools/process_iwyu.py"