replace use of deprecated new Buffer()

also replace use of deprecated isArray

Author: dlech

src/extension.ts

@@ -436,7 +436,7 @@ async function download(folder: vscode.WorkspaceFolder, device: Device): Promise
                 //   should be executable since Windows doesn't know about
                 //   POSIX file permissions.
                 let mode: string;
-                if (await verifyFileHeader(f.fsPath, new Buffer('#!/'))) {
+                if (await verifyFileHeader(f.fsPath, Buffer.from('#!/'))) {
                     mode = '755';
                 }
                 else {
@@ -448,7 +448,7 @@ async function download(folder: vscode.WorkspaceFolder, device: Device): Promise
 
                         // So, we check to see the file uses ELF format, if
                         // so, make it executable.
-                        if (await verifyFileHeader(f.fsPath, new Buffer('\x7fELF'))) {
+                        if (await verifyFileHeader(f.fsPath, Buffer.from('\x7fELF'))) {
                             stat.mode |= S_IXUSR;
                         }
                     }

src/utils.ts

@@ -2,7 +2,6 @@ import * as vscode from 'vscode';
 import * as temp from 'temp';
 import * as fs from 'fs';
 import * as os from 'os';
-import { isArray } from 'util';
 
 const toastDuration = 5000;
 
@@ -42,7 +41,7 @@ export function openAndRead(path: string, offset: number, length: number, positi
                 return;
             }
 
-            const buffer = new Buffer(length);
+            const buffer = Buffer.alloc(length);
             fs.read(fd, buffer, offset, length, position, (err, bytesRead, buffer) => {
                 fs.close(fd, err => console.log(err));
                 if (err) {
@@ -56,7 +55,7 @@ export function openAndRead(path: string, offset: number, length: number, positi
 }
 
 export async function verifyFileHeader(filePath: string, expectedHeader: Buffer | number[], offset: number = 0): Promise<boolean> {
-    const bufferExpectedHeader = isArray(expectedHeader) ? new Buffer(<number[]>expectedHeader) : <Buffer>expectedHeader;
+    const bufferExpectedHeader = Array.isArray(expectedHeader) ? Buffer.from(<number[]>expectedHeader) : <Buffer>expectedHeader;
     const header = await openAndRead(filePath, 0, bufferExpectedHeader.length, offset);
     return header.compare(bufferExpectedHeader) === 0;
 }