fix: make sure Buffer.alloc exit on node < 4.5.0 (#247)

.travis.yml

@@ -6,6 +6,8 @@ node_js:
   - '8'
   - '6'
   - '4'
+  - '4.4.7'
+  - '4.2.3'
 before_script:
   - echo -e "Host *\n\tStrictHostKeyChecking no\n" >> ~/.ssh/config
 script:

appveyor.yml

@@ -12,6 +12,7 @@ install:
   # Get the latest stable version of Node.js or io.js
   - ps: Install-Product node $env:nodejs_version
   # install modules
+  - npm cache clean --force
   - npm i --no-cache
 
 # Post-install test scripts.

lib/patch_buffer.js

@@ -0,0 +1,12 @@
+'use strict';
+
+// make sure buffer.alloc exists on 4.2.3 <= Node.js < 4.5.0
+// it use on tar@^4.0.0
+
+if (typeof Buffer.alloc === 'undefined') {
+  Buffer.alloc = function alloc(size, fill, encoding) {
+    const buf = new Buffer(size);
+    buf.fill(fill, encoding);
+    return buf;
+  };
+}

lib/utils.js

@@ -4,7 +4,10 @@ const debug = require('debug')('npminstall:utils');
 const fs = require('mz/fs');
 const path = require('path');
 const cp = require('child_process');
+
+require('./patch_buffer');
 const tar = require('tar');
+
 const zlib = require('zlib');
 const _rimraf = require('rimraf');
 const _mkdirp = require('mkdirp');