script: support JSON modules (#42138)

With import attributes enabled we can now support non javascript
modules, for now we are limited to json ones.
Switch `GlobalScope` `modulemap` to be keyed by the tuple url and
module's type.

Testing: Enabled a new directory, new tests should pass

---------

Signed-off-by: Gae24 <96017547+Gae24@users.noreply.github.com>
Signed-off-by: Josh Matthews <josh@joshmatthews.net>
Co-authored-by: Josh Matthews <josh@joshmatthews.net>

components/script/module_loading.rs

@@ -13,12 +13,12 @@ use std::collections::HashSet;
 use std::rc::Rc;
 
 use js::conversions::jsstr_to_string;
-use js::jsapi::{HandleValue as RawHandleValue, IsCyclicModule, JSObject};
+use js::jsapi::{HandleValue as RawHandleValue, IsCyclicModule, JSObject, ModuleType};
 use js::jsval::{ObjectValue, UndefinedValue};
 use js::realm::CurrentRealm;
 use js::rust::wrappers::{
-    GetModuleNamespace, GetRequestedModuleSpecifier, GetRequestedModulesCount, JS_GetModulePrivate,
-    ModuleEvaluate,
+    GetModuleNamespace, GetRequestedModuleSpecifier, GetRequestedModuleType,
+    GetRequestedModulesCount, JS_GetModulePrivate, ModuleEvaluate,
 };
 use js::rust::{HandleValue, IntoHandle};
 use net_traits::request::{Destination, Referrer};
@@ -145,6 +145,7 @@ fn inner_module_loading(
             // i. If AllImportAttributesSupported(request.[[Attributes]]) is false, then
             // Note: Gecko will call hasFirstUnsupportedAttributeKey on each module request,
             // GetRequestedModuleSpecifier will do it for us.
+            // In addition it will also check if specifier has an unknown module type.
             let jsstr = unsafe { GetRequestedModuleSpecifier(*cx, module_handle, index) };
 
             if jsstr.is_null() {
@@ -164,10 +165,12 @@ fn inner_module_loading(
             } else {
                 let specifier =
                     unsafe { jsstr_to_string(*cx, std::ptr::NonNull::new(jsstr).unwrap()) };
+                let module_type = unsafe { GetRequestedModuleType(*cx, module_handle, index) };
 
                 // ii. Else if module.[[LoadedModules]] contains a LoadedModuleRequest Record record
                 // such that ModuleRequestsEqual(record, request) is true, then
-                let loaded_module = module.find_descendant_inside_module_map(global, &specifier);
+                let loaded_module =
+                    module.find_descendant_inside_module_map(global, &specifier, module_type);
 
                 match loaded_module {
                     // 1. Perform InnerModuleLoading(state, record.[[Module]]).
@@ -183,6 +186,7 @@ fn inner_module_loading(
                             Some(module.clone()),
                             referrer.handle().into_handle(),
                             specifier,
+                            module_type,
                             state.load_state.clone(),
                             Payload::GraphRecord(state.clone()),
                         );
@@ -407,6 +411,7 @@ pub(crate) fn host_load_imported_module(
     referrer_module: Option<Rc<ModuleTree>>,
     referrer: RawHandleValue,
     specifier: String,
+    module_type: ModuleType,
     load_state: Option<Rc<LoadState>>,
     payload: Payload,
 ) {
@@ -541,12 +546,14 @@ pub(crate) fn host_load_imported_module(
     // Step 14 Fetch a single imported module script given url, fetchClient, destination, fetchOptions, settingsObject,
     // fetchReferrer, moduleRequest, and onSingleFetchComplete as defined below.
     // If loadState is not undefined and loadState.[[PerformFetch]] is not null, pass loadState.[[PerformFetch]] along as well.
+    // Note: we don't have access to the requested `ModuleObject`, so we pass only its type.
     fetch_a_single_imported_module_script(
         url.unwrap(),
         fetch_client,
         destination,
         fetch_options,
         fetch_referrer,
+        module_type,
         on_single_fetch_complete,
     );
 }
@@ -558,6 +565,7 @@ fn fetch_a_single_imported_module_script(
     destination: Destination,
     options: ScriptFetchOptions,
     referrer: Referrer,
+    module_type: ModuleType,
     on_complete: impl FnOnce(Option<Rc<ModuleTree>>) + 'static,
 ) {
     // TODO Step 1. Assert: moduleRequest.[[Attributes]] does not contain any Record entry such that entry.[[Key]] is not "type",
@@ -565,8 +573,12 @@ fn fetch_a_single_imported_module_script(
 
     // TODO Step 2. Let moduleType be the result of running the module type from module request steps given moduleRequest.
 
-    // TODO Step 3. If the result of running the module type allowed steps given moduleType and settingsObject is false,
+    // Step 3. If the result of running the module type allowed steps given moduleType and settingsObject is false,
     // then run onComplete given null, and return.
+    match module_type {
+        ModuleType::Unknown => return on_complete(None),
+        ModuleType::JavaScript | ModuleType::JSON => (),
+    }
 
     // Step 4. Fetch a single module script given url, fetchClient, destination, options, settingsObject, referrer,
     // moduleRequest, false, and onComplete. If performFetch was given, pass it along as well.
@@ -576,6 +588,7 @@ fn fetch_a_single_imported_module_script(
         destination,
         options,
         referrer,
+        Some(module_type),
         false,
         Some(IntroductionType::IMPORTED_MODULE),
         on_complete,