remove duplicate of PATH environment variable on Windows

src/__tests__/index.js

@@ -2,6 +2,7 @@ const crossSpawnMock = require('cross-spawn')
 const isWindowsMock = require('../is-windows')
 
 jest.mock('../is-windows')
+jest.mock('../patch-path')
 jest.mock('cross-spawn')
 
 const crossEnv = require('../')

src/__tests__/patch-path.js

@@ -0,0 +1,22 @@
+const patchPathEnv = require('../patch-path')
+const isWindowsMock = require('../is-windows')
+
+jest.mock('../is-windows')
+
+beforeEach(() => {
+  isWindowsMock.mockReturnValue(true)
+})
+
+test(`remove duplicate of PATH variable if the current OS is Windows`, () => {
+  isWindowsMock.mockReturnValue(true)
+  const env = {PATH: 'path1', Path: 'path2'}
+  patchPathEnv(env)
+  expect(env).toStrictEqual({PATH: 'path1'})
+})
+
+test(`do nothing if the current OS is not Windows`, () => {
+  isWindowsMock.mockReturnValue(false)
+  const env = {PATH: 'path1', Path: 'path2'}
+  patchPathEnv(env)
+  expect(env).toStrictEqual({PATH: 'path1', Path: 'path2'})
+})

src/index.js

@@ -1,12 +1,14 @@
 const {spawn} = require('cross-spawn')
 const commandConvert = require('./command')
 const varValueConvert = require('./variable')
+const patchPathEnv = require('./patch-path')
 
 module.exports = crossEnv
 
 const envSetterRegex = /(\w+)=('(.*)'|"(.*)"|(.*))/
 
 function crossEnv(args, options = {}) {
+  patchPathEnv(process.env)
   const [envSetters, command, commandArgs] = parseCommand(args)
   const env = getEnvVars(envSetters)
   if (command) {

src/patch-path.js

@@ -0,0 +1,9 @@
+const isWindows = require('./is-windows')
+
+module.exports = patchPathEnv
+
+function patchPathEnv(env) {
+  if (isWindows() && env.Path && env.PATH) {
+    delete env.Path
+  }
+}