refactor: drop extend and lodash.flatten

package.json

@@ -11,14 +11,12 @@
     "@grpc/grpc-js": "^0.3.0",
     "@grpc/proto-loader": "^0.3.0",
     "duplexify": "^3.6.0",
-    "extend": "^3.0.1",
     "globby": "^8.0.1",
     "google-auth-library": "^2.0.0",
     "google-proto-files": "^0.17.0",
     "grpc": "^1.15.1",
     "is-stream-ended": "^0.1.4",
     "lodash.at": "^4.6.0",
-    "lodash.flatten": "^4.4.0",
     "lodash.has": "^4.5.2",
     "protobufjs": "^6.8.8",
     "retry-request": "^4.0.0",
@@ -27,10 +25,8 @@
   "devDependencies": {
     "@types/chai": "^4.1.3",
     "@types/duplexify": "^3.5.0",
-    "@types/extend": "^3.0.0",
     "@types/globby": "^8.0.0",
     "@types/lodash.at": "^4.6.4",
-    "@types/lodash.flatten": "^4.4.4",
     "@types/lodash.has": "^4.5.4",
     "@types/mocha": "^5.2.1",
     "@types/node": "^10.3.2",

src/index.ts

@@ -29,8 +29,6 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-import * as extend from 'extend';
-
 import {GrpcClient, GrpcClientOptions} from './grpc';
 import * as operationsClient from './operations_client';
 import * as routingHeader from './routing_header';
@@ -48,7 +46,7 @@ export {StreamDescriptor, StreamType} from './streaming';
 export {routingHeader};
 
 function lro(options: GrpcClientOptions) {
-  options = extend({scopes: lro.ALL_SCOPES}, options);
+  options = Object.assign({scopes: lro.ALL_SCOPES}, options);
   const gaxGrpc = new GrpcClient(options);
   return new operationsClient.OperationsClientBuilder(gaxGrpc);
 }

src/operations_client.ts

@@ -24,18 +24,16 @@
  * merge preserves those additions if the generated source changes.
  */
 
-import * as extend from 'extend';
-
 import * as apiCallable from './api_callable';
 import * as gax from './gax';
 import * as pagedIteration from './paged_iteration';
 import * as pathTemplate from './path_template';
 
 const configData = require('./operations_client_config');
 
-extend(gax, apiCallable);
-extend(gax, pathTemplate);
-extend(gax, pagedIteration);
+Object.assign(gax, apiCallable);
+Object.assign(gax, pathTemplate);
+Object.assign(gax, pagedIteration);
 
 export const SERVICE_ADDRESS = 'longrunning.googleapis.com';
 
@@ -76,7 +74,7 @@ export class OperationsClient {
   auth;
 
   constructor(gaxGrpc, grpcClients, opts) {
-    opts = extend(
+    opts = Object.assign(
         {
           servicePath: SERVICE_ADDRESS,
           port: DEFAULT_SERVICE_PORT,
@@ -438,7 +436,7 @@ export class OperationsClientBuilder {
     const protoFilesRoot = require('google-proto-files')('..');
     const operationsClient = gaxGrpc.loadProto(
         protoFilesRoot, 'google/longrunning/operations.proto');
-    extend(this, operationsClient.google.longrunning);
+    Object.assign(this, operationsClient.google.longrunning);
 
     /**
      * Build a new instance of {@link OperationsClient}.
@@ -457,6 +455,6 @@ export class OperationsClientBuilder {
     this['operationsClient'] = opts => {
       return new OperationsClient(gaxGrpc, operationsClient, opts);
     };
-    extend(this['operationsClient'], OperationsClient);
+    Object.assign(this['operationsClient'], OperationsClient);
   }
 }

src/paged_iteration.ts

@@ -29,7 +29,6 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-import * as extend from 'extend';
 import * as ended from 'is-stream-ended';
 import {PassThrough, Transform} from 'stream';
 
@@ -83,7 +82,7 @@ export class PagedIteration extends NormalApiCaller {
   }
 
   call(apiCall: APICall, argument: {[index: string]: {}}, settings, canceller) {
-    argument = extend({}, argument);
+    argument = Object.assign({}, argument);
     if (settings.pageToken) {
       argument[this.pageDescriptor.requestPageTokenField] = settings.pageToken;
     }
@@ -160,7 +159,7 @@ export class PageDescriptor {
    */
   createStream(apiCall, request, options): Transform {
     const stream = new PassThrough({objectMode: true});
-    options = extend({}, options, {autoPaginate: false});
+    options = Object.assign({}, options, {autoPaginate: false});
     const maxResults = 'maxResults' in options ? options.maxResults : -1;
     let pushCount = 0;
     let started = false;

src/path_template_parser.pegjs

@@ -32,7 +32,6 @@
  */
 
 {
-   const flatten = require('lodash.flatten');
    const extras = require('./parser_extras');
 }
 
@@ -55,11 +54,11 @@ bound_segment
 
 variable
   = '{' l:literal '=' segments:unbound_segments '}' {
-    return flatten([
+    return ([
       { kind: extras.BINDING,     literal: l },
       segments,
       { kind: extras.END_BINDING, literal: '' }
-    ]);
+    ]).reduce((a, b) => a.concat(b), []);
   }
   / '{' l:literal '}' {
     return [

src/path_template_parser.ts

@@ -51,11 +51,12 @@ module.exports = (() => {
     const peg$c9 = '}';
     const peg$c10 = {type: 'literal', value: '}', description: '"}"'};
     const peg$c11 = (l, segments) => {
-      return flatten([
-        {kind: extras.BINDING, literal: l},
-        segments,
-        {kind: extras.END_BINDING, literal: ''},
-      ]);
+      return ([
+               {kind: extras.BINDING, literal: l},
+               segments,
+               {kind: extras.END_BINDING, literal: ''},
+             ])
+          .reduce((a, b) => a.concat(b), []);
     };
     const peg$c12 = l => {
       return [
@@ -617,7 +618,6 @@ module.exports = (() => {
       return s0;
     }
 
-    const flatten = require('lodash.flatten');
     const extras = require('./parser_extras');
 
     peg$result = peg$startRuleFunction();