fix: Avoid path concatenation

lib/mungers/cmd.js

@@ -33,9 +33,9 @@ function mungeCmd(workingDir, options) {
   if (m) {
     originalNode = m[2]
     // TODO: Remove `replace`: seems unused
-    replace = m[1] + workingDir + '/node.cmd' + m[3] + m[4]
+    replace = m[1] + path.join(workingDir, 'node.cmd') + m[3] + m[4]
     newArgs[cmdi + 1] = m[1] + m[2] + m[3] +
-      ' "' + workingDir + '\\node"' + m[4]
+      ' "' + path.join(workingDir, 'node') + '"' + m[4]
   } else {
     // XXX probably not a good idea to rewrite to the first npm in the
     // path if it's a full path to npm.  And if it's not a full path to
@@ -46,8 +46,8 @@ function mungeCmd(workingDir, options) {
     }
 
     let npmPath = whichOrUndefined('npm') || 'npm'
-    npmPath = path.dirname(npmPath) + '\\node_modules\\npm\\bin\\npm-cli.js'
-    replace = m[1] + '"' + workingDir + '/node.cmd"' +
+    npmPath = path.join(path.dirname(npmPath), 'node_modules', 'npm', 'bin', 'npm-cli.js')
+    replace = m[1] + '"' + path.join(workingDir, 'node.cmd') + '"' +
       ' "' + npmPath + '"' +
       m[3] + m[4]
     newArgs[cmdi + 1] = command.replace(npmre, replace)

lib/mungers/env.js

@@ -5,7 +5,6 @@ const path = require("path")
 const homedir = require("../homedir")
 
 const pathRe = isWindows() ? /^PATH=/i : /^PATH=/;
-const colon = isWindows() ? ';' : ':'
 
 /**
  * Updates the environment variables to intercept `node` commands and pass down options.
@@ -23,7 +22,7 @@ function mungeEnv(workingDir, options) {
       // `5` corresponds to the length of `PATH=`
       pathEnv = ep.substr(5)
       const k = ep.substr(0, 5)
-      return k + workingDir + colon + pathEnv
+      return k + workingDir + path.delimiter + pathEnv
     } else {
       // Return as-is
       return ep;

lib/mungers/node.js

@@ -56,7 +56,7 @@ function mungeNode(workingDir, options) {
   let newFile = options.file;
 
   if (hasMain) {
-    const replace = workingDir + '/' + command
+    const replace = path.join(workingDir, command)
     newArgs.splice(mainIndex, 0, replace)
   }
 

lib/mungers/sh.js

@@ -37,18 +37,19 @@ function mungeSh(workingDir, options) {
   let newArgs = [...options.args];
   // Remember the original Node command to use it in the shim
   let originalNode;
+  const workingNode = path.join(workingDir, 'node')
 
   if (isNode(exe)) {
     originalNode = command
-    c = match[1] + match[2] + ' "' + workingDir + '/node" ' + match[3]
+    c = `${match[1]}${match[2]} "${workingNode}" ${match[3]}`
     newArgs[cmdi + 1] = c
   } else if (exe === 'npm' && !isWindows()) {
     // XXX this will exhibit weird behavior when using /path/to/npm,
     // if some other npm is first in the path.
     const npmPath = whichOrUndefined('npm')
 
     if (npmPath) {
-      c = c.replace(re, '$1 "' + workingDir + '/node" "' + npmPath + '" $3')
+      c = c.replace(re, `$1 "${workingNode}" "${npmPath}" $3`)
       newArgs[cmdi + 1] = c
       debug('npm munge!', c)
     }

lib/mungers/shebang.js

@@ -32,7 +32,7 @@ function mungeShebang(workingDir, options) {
 
   const originalNode = shebangbin
   const file = shebangbin
-  const args = [shebangbin, workingDir + '/' + maybeNode]
+  const args = [shebangbin, path.join(workingDir, maybeNode)]
     .concat(resolved)
     .concat(match[1].split(' ').slice(1))
     .concat(options.args.slice(1))