build: use TypeScript ^3.8.3, set lib to es2018 (#760)

* build: use TypeScript ^3.8.3, set lib to es2018

* fix: better typing

Author: alexander-fenster

package.json

@@ -84,7 +84,7 @@
     "stream-events": "^1.0.4",
     "through2": "^3.0.0",
     "ts-loader": "^6.0.3",
-    "typescript": "3.6.4",
+    "typescript": "^3.8.3",
     "webpack": "^4.34.0",
     "webpack-cli": "^3.3.4"
   },

src/operationsClient.ts

@@ -82,14 +82,14 @@ export class OperationsClient {
     operationsProtos: any,
     options: OperationsClientOptions
   ) {
-    const opts: OperationsClientOptions & ClientStubOptions = Object.assign(
+    const opts = Object.assign(
       {
         servicePath: SERVICE_ADDRESS,
         port: DEFAULT_SERVICE_PORT,
         clientConfig: {},
       },
       options
-    );
+    ) as OperationsClientOptions & ClientStubOptions;
 
     const googleApiClient = ['gl-node/' + process.versions.node];
     if (opts.libName && opts.libVersion) {

tsconfig.json

@@ -1,7 +1,7 @@
 {
   "extends": "./node_modules/gts/tsconfig-google.json",
   "compilerOptions": {
-    "lib": ["es2015", "dom"],
+    "lib": ["es2018", "dom"],
     "rootDir": ".",
     "outDir": "build",
     "noImplicitAny": true,