fix: consolidate node version support logic

lib/cli.js

@@ -11,9 +11,25 @@ module.exports = async process => {
   // so now both broken and unsupported use console, but only broken
   // will process.exit. It is important to now perform *both* of these
   // checks as early as possible so the user gets the error message.
-  const { checkForBrokenNode, checkForUnsupportedNode } = require('./utils/unsupported.js')
-  checkForBrokenNode()
-  checkForUnsupportedNode()
+  const semver = require('semver')
+  const supported = require('../package.json').engines.node
+  const knownBroken = '<6.2.0 || 9 <9.3.0'
+
+  const nodejsVersion = process.version.replace(/-.*$/, '')
+  /* eslint-disable no-console */
+  if (semver.satisfies(nodejsVersion, knownBroken)) {
+    console.error('ERROR: npm is known not to run on Node.js ' + process.version)
+    console.error("You'll need to upgrade to a newer Node.js version in order to use this")
+    console.error('version of npm. You can find the latest version at https://nodejs.org/')
+    process.exit(1)
+  }
+  if (!semver.satisfies(nodejsVersion, supported)) {
+    console.error('npm does not support Node.js ' + process.version)
+    console.error('You should probably upgrade to a newer version of node as we')
+    console.error("can't make any promises that npm will work with this version.")
+    console.error('You can find the latest version at https://nodejs.org/')
+  }
+  /* eslint-enable no-console */
 
   const exitHandler = require('./utils/exit-handler.js')
   process.on('uncaughtException', exitHandler)

test/lib/cli.js

@@ -14,10 +14,6 @@ const cliMock = async (t, opts) => {
   const { Npm, outputs, logMocks, logs } = await loadMockNpm(t, { ...opts, init: false })
   const cli = t.mock('../../lib/cli.js', {
     '../../lib/npm.js': Npm,
-    '../../lib/utils/unsupported.js': {
-      checkForBrokenNode: () => {},
-      checkForUnsupportedNode: () => {},
-    },
     '../../lib/utils/exit-handler.js': exitHandlerMock,
     ...logMocks,
   })
@@ -175,3 +171,38 @@ t.test('load error calls error handler', async t => {
   await cli(process)
   t.strictSame(exitHandlerCalled(), [err])
 })
+
+t.test('known broken node version', async t => {
+  const errors = []
+  let exitCode
+  const { cli } = await cliMock(t, {
+    globals: {
+      'console.error': (msg) => errors.push(msg),
+      'process.version': '6.0.0',
+      'process.exit': e => exitCode = e,
+    },
+  })
+  await cli(process)
+  t.match(errors, [
+    'ERROR: npm is known not to run on Node.js 6.0.0',
+    'You\'ll need to upgrade to a newer Node.js version in order to use this',
+    'version of npm. You can find the latest version at https://nodejs.org/',
+  ])
+  t.match(exitCode, 1)
+})
+
+t.test('unsupported node version', async t => {
+  const errors = []
+  const { cli } = await cliMock(t, {
+    globals: {
+      'console.error': (msg) => errors.push(msg),
+      'process.version': '10.0.0',
+    },
+  })
+  await cli(process)
+  t.match(errors, [
+    'npm does not support Node.js 10.0.0',
+    'You should probably upgrade to a newer version of node as we',
+    'can\'t make any promises that npm will work with this version.',
+  ])
+})