LibWeb/WebAssembly: Implement Module::imports(module)

Author: https://github.com/alimpfard
Commit: f984c1cc51
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/4423
Reviewed-by: https://github.com/ADKaster ✅

Libraries/LibWeb/WebAssembly/Module.cpp

@@ -33,6 +33,39 @@ WebIDL::ExceptionOr<GC::Ref<Module>> Module::construct_impl(JS::Realm& realm, GC
     return realm.create<Module>(realm, move(compiled_module));
 }
 
+// https://webassembly.github.io/threads/js-api/index.html#dom-module-imports
+WebIDL::ExceptionOr<Vector<ModuleImportDescriptor>> Module::imports(JS::VM&, GC::Ref<Module> module_object)
+{
+    // 1. Let module be moduleObject.[[Module]].
+    // 2. Let imports be « ».
+    Vector<ModuleImportDescriptor> import_objects;
+
+    // 3. For each (moduleName, name, type) of module_imports(module),
+    auto& imports = module_object->m_compiled_module->module->import_section().imports();
+    import_objects.ensure_capacity(imports.size());
+    for (auto& import : imports) {
+        // 3.1. Let kind be the string value of the extern type type.
+        auto const kind = import.description().visit(
+            [](Wasm::TypeIndex) { return Bindings::ImportExportKind::Function; },
+            [](Wasm::TableType) { return Bindings::ImportExportKind::Table; },
+            [](Wasm::MemoryType) { return Bindings::ImportExportKind::Memory; },
+            [](Wasm::GlobalType) { return Bindings::ImportExportKind::Global; },
+            [](Wasm::FunctionType) { return Bindings::ImportExportKind::Function; });
+
+        // 3.2. Let obj be «[ "module" → moduleName, "name" → name, "kind" → kind ]».
+        ModuleImportDescriptor descriptor {
+            .module = String::from_utf8_with_replacement_character(import.module()),
+            .name = String::from_utf8_with_replacement_character(import.name()),
+            .kind = kind,
+        };
+
+        // 3.3. Append obj to imports.
+        import_objects.append(move(descriptor));
+    }
+    // 4. Return imports.
+    return import_objects;
+}
+
 Module::Module(JS::Realm& realm, NonnullRefPtr<Detail::CompiledWebAssemblyModule> compiled_module)
     : Bindings::PlatformObject(realm)
     , m_compiled_module(move(compiled_module))

Libraries/LibWeb/WebAssembly/Module.h

@@ -10,19 +10,32 @@
 #include <LibGC/Ptr.h>
 #include <LibGC/Root.h>
 #include <LibJS/Forward.h>
+#include <LibJS/Runtime/Array.h>
 #include <LibWasm/Types.h>
 #include <LibWeb/Bindings/ExceptionOrUtils.h>
 #include <LibWeb/Bindings/PlatformObject.h>
 #include <LibWeb/WebAssembly/WebAssembly.h>
 
+namespace Web::Bindings {
+enum class ImportExportKind : u8;
+}
+
 namespace Web::WebAssembly {
 
+// FIXME: This should really be generated by the IDL generator.
+struct ModuleImportDescriptor {
+    String module;
+    String name;
+    Bindings::ImportExportKind kind;
+};
+
 class Module : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(Module, Bindings::PlatformObject);
     GC_DECLARE_ALLOCATOR(Module);
 
 public:
     static WebIDL::ExceptionOr<GC::Ref<Module>> construct_impl(JS::Realm&, GC::Root<WebIDL::BufferSource>& bytes);
+    static WebIDL::ExceptionOr<Vector<ModuleImportDescriptor>> imports(JS::VM&, GC::Ref<Module>);
 
     NonnullRefPtr<Detail::CompiledWebAssemblyModule> compiled_module() const { return m_compiled_module; }
 

Libraries/LibWeb/WebAssembly/Module.idl

@@ -6,14 +6,14 @@ enum ImportExportKind {
 };
 
 dictionary ModuleExportDescriptor {
-    required USVString name;
-    required ImportExportKind kind;
+    required [GenerateAsRequired] USVString name;
+    required [GenerateAsRequired] ImportExportKind kind;
 };
 
 dictionary ModuleImportDescriptor {
-    required USVString module;
-    required USVString name;
-    required ImportExportKind kind;
+    required [GenerateAsRequired] USVString module;
+    required [GenerateAsRequired] USVString name;
+    required [GenerateAsRequired] ImportExportKind kind;
 };
 
 // https://webassembly.github.io/spec/js-api/#modules
@@ -22,6 +22,6 @@ interface Module {
     constructor(BufferSource bytes);
 
     [FIXME] static sequence<ModuleExportDescriptor> exports(Module moduleObject);
-    [FIXME] static sequence<ModuleImportDescriptor> imports(Module moduleObject);
+    static sequence<ModuleImportDescriptor> imports(Module moduleObject);
     [FIXME] static sequence<ArrayBuffer> customSections(Module moduleObject, DOMString sectionName);
 };