added unit testing, and started implementing unit tests...phew

node_modules/global-prefix/index.js

@@ -0,0 +1,96 @@
+/*!
+ * global-prefix <https://github.com/jonschlinkert/global-prefix>
+ *
+ * Copyright (c) 2015-2017 Jon Schlinkert.
+ * Licensed under the MIT license.
+ */
+
+'use strict';
+
+var fs = require('fs');
+var path = require('path');
+var expand = require('expand-tilde');
+var homedir = require('homedir-polyfill');
+var ini = require('ini');
+var prefix;
+
+function getPrefix() {
+  if (process.env.PREFIX) {
+    prefix = process.env.PREFIX;
+  } else {
+    // Start by checking if the global prefix is set by the user
+    var home = homedir();
+    if (home) {
+      // homedir() returns undefined if $HOME not set; path.resolve requires strings
+      var userConfig = path.resolve(home, '.npmrc');
+      prefix = tryConfigPath(userConfig);
+    }
+
+    if (!prefix) {
+      // Otherwise find the path of npm
+      var npm = tryNpmPath();
+      if (npm) {
+        // Check the built-in npm config file
+        var builtinConfig = path.resolve(npm, '..', '..', 'npmrc');
+        prefix = tryConfigPath(builtinConfig);
+
+        if (prefix) {
+          // Now the global npm config can also be checked.
+          var globalConfig = path.resolve(prefix, 'etc', 'npmrc');
+          prefix = tryConfigPath(globalConfig) || prefix;
+        }
+      }
+
+      if (!prefix) fallback();
+    }
+  }
+
+  if (prefix) {
+    return expand(prefix);
+  }
+}
+
+function fallback() {
+  var isWindows = require('is-windows');
+  if (isWindows()) {
+    // c:\node\node.exe --> prefix=c:\node\
+    prefix = process.env.APPDATA
+      ? path.join(process.env.APPDATA, 'npm')
+      : path.dirname(process.execPath);
+  } else {
+    // /usr/local/bin/node --> prefix=/usr/local
+    prefix = path.dirname(path.dirname(process.execPath));
+
+    // destdir only is respected on Unix
+    if (process.env.DESTDIR) {
+      prefix = path.join(process.env.DESTDIR, prefix);
+    }
+  }
+}
+
+function tryNpmPath() {
+  try {
+    return fs.realpathSync(require('which').sync('npm'));
+  } catch (err) {}
+  return null;
+}
+
+function tryConfigPath(configPath) {
+  try {
+    var data = fs.readFileSync(configPath, 'utf-8');
+    var config = ini.parse(data);
+    if (config.prefix) return config.prefix;
+  } catch (err) {}
+  return null;
+}
+
+/**
+ * Expose `prefix`
+ */
+
+Object.defineProperty(module, 'exports', {
+  enumerable: true,
+  get: function() {
+    return prefix || (prefix = getPrefix());
+  }
+});