utils.ts

/**
 * Copyright 2020 Google Inc. All Rights Reserved.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *     http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * Notice: I (Jamie Sinclair) have modified this file
 * - Allows manual instantiation of the Wasm Module.
 */

export function initEmscriptenModule<T extends EmscriptenWasm.Module>(
  moduleFactory: EmscriptenWasm.ModuleFactory<T>,
  wasmModule?: WebAssembly.Module,
  moduleOptionOverrides: Partial<EmscriptenWasm.ModuleOpts> = {},
): Promise<T> {
  let instantiateWasm;

  if (wasmModule) {
    instantiateWasm = (
      imports: WebAssembly.Imports,
      callback: (instance: WebAssembly.Instance) => void,
    ) => {
      const instance = new WebAssembly.Instance(wasmModule, imports);
      callback(instance);
      return instance.exports;
    };
  }

  return moduleFactory({
    // Just to be safe, don't automatically invoke any wasm functions
    noInitialRun: true,
    instantiateWasm,
    ...moduleOptionOverrides,
  });
}