Improve ES6 support in TypeScript definitions generation

Users building with --emit-tsd and the EXPORT_ES6 setting should get
TypeScript definitions accounting for the fact that ES6 modules
include a default export that is a functor to instantiate and access
the wasm module in question

When generating TS definitions, query the EXPORT_ES6 setting and,
if present, add the appropriate exports to the output

Author: jnickg

test/other/embind_tsgen_es6.d.ts

@@ -0,0 +1,114 @@
+// TypeScript bindings for emscripten-generated code.  Automatically generated at compile time.
+interface WasmModule {
+  _main(_0: number, _1: number): number;
+}
+
+export interface Test {
+  x: number;
+  readonly y: number;
+  functionOne(_0: number, _1: number): number;
+  functionTwo(_0: number, _1: number): number;
+  functionFour(_0: boolean): number;
+  functionFive(x: number, y: number): number;
+  constFn(): number;
+  longFn(_0: number): number;
+  functionThree(_0: ArrayBuffer|Uint8Array|Uint8ClampedArray|Int8Array|string): number;
+  functionSix(str: ArrayBuffer|Uint8Array|Uint8ClampedArray|Int8Array|string): number;
+  delete(): void;
+}
+
+export interface BarValue<T extends number> {
+  value: T;
+}
+export type Bar = BarValue<0>|BarValue<1>|BarValue<2>;
+
+export interface EmptyEnumValue<T extends number> {
+  value: T;
+}
+export type EmptyEnum = never/* Empty Enumerator */;
+
+export type ValArrIx = [ Bar, Bar, Bar, Bar ];
+
+export interface IntVec {
+  push_back(_0: number): void;
+  resize(_0: number, _1: number): void;
+  size(): number;
+  get(_0: number): number | undefined;
+  set(_0: number, _1: number): boolean;
+  delete(): void;
+}
+
+export interface MapIntInt {
+  keys(): IntVec;
+  get(_0: number): number | undefined;
+  set(_0: number, _1: number): void;
+  size(): number;
+  delete(): void;
+}
+
+export interface Foo {
+  process(_0: Test): void;
+  delete(): void;
+}
+
+export type ValObj = {
+  foo: Foo,
+  bar: Bar
+};
+
+export interface ClassWithConstructor {
+  fn(_0: number): number;
+  delete(): void;
+}
+
+export interface ClassWithTwoConstructors {
+  delete(): void;
+}
+
+export interface ClassWithSmartPtrConstructor {
+  fn(_0: number): number;
+  delete(): void;
+}
+
+export interface BaseClass {
+  fn(_0: number): number;
+  delete(): void;
+}
+
+export interface DerivedClass extends BaseClass {
+  fn2(_0: number): number;
+  delete(): void;
+}
+
+export type ValArr = [ number, number, number ];
+
+interface EmbindModule {
+  Test: {staticFunction(_0: number): number; staticFunctionWithParam(x: number): number; staticProperty: number};
+  class_returning_fn(): Test;
+  class_unique_ptr_returning_fn(): Test;
+  a_class_instance: Test;
+  an_enum: Bar;
+  Bar: {valueOne: BarValue<0>, valueTwo: BarValue<1>, valueThree: BarValue<2>};
+  EmptyEnum: {};
+  enum_returning_fn(): Bar;
+  IntVec: {new(): IntVec};
+  MapIntInt: {new(): MapIntInt};
+  Foo: {};
+  ClassWithConstructor: {new(_0: number, _1: ValArr): ClassWithConstructor};
+  ClassWithTwoConstructors: {new(): ClassWithTwoConstructors; new(_0: number): ClassWithTwoConstructors};
+  ClassWithSmartPtrConstructor: {new(_0: number, _1: ValArr): ClassWithSmartPtrConstructor};
+  BaseClass: {};
+  DerivedClass: {};
+  a_bool: boolean;
+  an_int: number;
+  optional_test(_0: Foo | undefined): number | undefined;
+  global_fn(_0: number, _1: number): number;
+  smart_ptr_function(_0: ClassWithSmartPtrConstructor): number;
+  smart_ptr_function_with_params(foo: ClassWithSmartPtrConstructor): number;
+  function_with_callback_param(_0: (message: string) => void): number;
+  string_test(_0: ArrayBuffer|Uint8Array|Uint8ClampedArray|Int8Array|string): string;
+  wstring_test(_0: string): string;
+}
+export type MainModule = WasmModule & EmbindModule;
+export type MainModuleFunctor = () => Promise<MainModule>;
+export default MainModuleFunctor;

test/test_other.py

@@ -3189,7 +3189,7 @@ def test_embind_tsgen_ignore(self):
                   '-sMINIMAL_RUNTIME=2',
                   '-sEXPORT_ES6=1']
     self.emcc(test_file('other/embind_tsgen.cpp'), extra_args)
-    self.assertFileContents(test_file('other/embind_tsgen_ignore_2.d.ts'), read_file('embind_tsgen.d.ts'))
+    self.assertFileContents(test_file('other/embind_tsgen_ignore_2.d.ts'), read_file('embind_tsgen_es6.d.ts'))
     # Also test this separately since it conflicts with other settings.
     extra_args = ['-sWASM=0']
     self.emcc(test_file('other/embind_tsgen.cpp'), extra_args)

tools/emscripten.py

@@ -631,6 +631,9 @@ def create_tsd(metadata, embind_tsd):
   if embind_tsd:
     export_interfaces += ' & EmbindModule'
   out += f'export type MainModule = {export_interfaces};\n'
+  if settings.EXPORT_ES6 and settings.MODULARIZE:
+    out += 'export type MainModuleFunctor = () => Promise<MainModule>;\n'
+    out += 'export default MainModuleFunctor;\n'
   return out