feat(getloader): refactor getting loader into closure

src/getLoader.ts

@@ -0,0 +1,38 @@
+import { ENVIRONMENT, getModuleLoader, isNode } from 'emscripten-wasm-loader';
+import { CldAsmModule } from './cldAsmModule';
+import { CldFactory } from './cldFactory';
+import { cldLoader } from './cldLoader';
+import { log } from './util/logger';
+
+/**
+ * @internal
+ * Creates loadModule function.
+ *
+ * @param {binaryPath} string Path to import wasm / asm.js binary via `require`
+ * @param {binaryEndpoint} [string] For overring path to wasm binary on node.js or browser.
+ * @param {environment} [ENVIRONMENT] For overriding running environment
+ *
+ * @returns {(binaryEndpoint?: string, environment?: ENVIRONMENT) => Promise<CldFactory>} Function to load module
+ */
+const getLoader = async (binaryPath: string, binaryEndpoint?: string, environment?: ENVIRONMENT) => {
+  log(`loadModule: load cld3 module loader from `, binaryPath);
+
+  //imports MODULARIZED emscripten preamble
+  //tslint:disable-next-line:no-require-imports no-var-requires
+  const runtimeModule = require(`${binaryPath}/cld3`);
+  //do not supply this into moduleLoader, emscripten-wasm-loader does its own job to get environment
+  const env = environment ? environment : isNode() ? ENVIRONMENT.NODE : ENVIRONMENT.WEB;
+
+  const moduleLoader = await getModuleLoader<CldFactory, CldAsmModule>(
+    (runtime: CldAsmModule, env: ENVIRONMENT) => cldLoader(runtime, env),
+    {
+      //tslint:disable-next-line:no-require-imports
+      dir: env === ENVIRONMENT.NODE ? require('path').dirname(require.resolve(`${binaryPath}/cld3`)) : null,
+      runtimeModule
+    }
+  );
+
+  return moduleLoader(binaryEndpoint, environment);
+};
+
+export { getLoader };