Enforces global dependencies are available.

packages/ignite-cli/package.json

@@ -32,10 +32,11 @@
     "gluegun": "^0.16.0",
     "gluegun-patching": "^0.3.0",
     "minimist": "^1.2.0",
+    "pretty-error": "^2.0.2",
     "ramda": "^0.23.0",
     "ramdasauce": "^1.2.0",
-    "shelljs": "^0.7.6",
-    "pretty-error": "^2.0.2"
+    "semver": "^5.3.0",
+    "shelljs": "^0.7.6"
   },
   "devDependencies": {
     "ava": "^0.18.1",

packages/ignite-cli/src/cli/check.js

@@ -1,34 +1,52 @@
+// NOTE:  this file is intentionally written with es3
+
 // check the node version
 var Sniff = require('gluegun/sniff')
-var Shell = require('shelljs')
 
 // check the node version
 if (!Sniff.isNewEnough) {
-  console.log('Node.js 7.6+ is required to run. You have ' + Sniff.nodeVersion + '. Womp, womp.')
+  console.log(
+    'Node.js 7.6+ is required to run. You have ' +
+      Sniff.nodeVersion +
+      '. Womp, womp.'
+  )
   process.exit(1)
 }
 
 // check for async and await
 if (!Sniff.hasAsyncAwait) {
-  console.log('The async feature is not available. Please ensure your Node is up to date.')
+  console.log(
+    'The async feature is not available. Please ensure your Node is up to date.'
+  )
   process.exit(2)
 }
 
-// check the yarn version is >= 0.20
-function getYarnVersion () {
-  return Shell.exec('yarn --version', {silent: true}).stdout.replace('\n', '').split('.')
-}
+// lets check our global dependencies
+var enforceGlobalDependency = require('./enforceGlobalDependency')
+var exitCodes = require('../lib/exitCodes')
 
-function checkYarn (yarnVersion) {
-  var major = parseInt(yarnVersion[0], 10)
-  var minor = parseInt(yarnVersion[1], 10)
-  return (major >= 1) || (minor >= 20)
-}
+// react-native-cli
+var rnCli = enforceGlobalDependency({
+  optional: false,
+  range: '>=2.0.0',
+  which: 'react-native',
+  versionCommand: 'react-native --version',
+  installMessage: 'To install: npm i -g react-native-cli'
+})
 
-var hasYarn = Shell.which('yarn')
-if (hasYarn && !checkYarn(getYarnVersion())) {
-  console.log('You have yarn installed but it\'s version ' + getYarnVersion().join('.') + '. Ignite requires yarn 20.0+.')
-  console.log('Run `brew upgrade yarn` if you use Homebrew or visit https://yarnpkg.com/en/docs/install.')
-  process.exit(3)
+if (!rnCli) {
+  process.exit(exitCodes.INVALID_GLOBAL_DEPENDENCY)
 }
 
+// yarn
+var yarn = enforceGlobalDependency({
+  optional: true,
+  range: '>=0.21.0',
+  which: 'yarn',
+  versionCommand: 'yarn --version',
+  installMessage: 'See https://yarnpkg.com/en/docs/install on how to upgrade for your OS.'
+})
+
+if (!yarn) {
+  process.exit(exitCodes.INVALID_GLOBAL_DEPENDENCY)
+}

packages/ignite-cli/src/cli/enforceGlobalDependency.js

@@ -0,0 +1,125 @@
+// NOTE: this file is intentionally written with es3
+var shell = require('shelljs')
+var semver = require('semver')
+var ramda = require('ramda')
+
+/**
+ * Extracts the version number from a somewhere within a string.
+ *
+ * This looks for things that look like semver (e.g. 0.0.0) and picks the first one.
+ *
+ * @param {string} raw - The raw text which came from running the version command.
+ */
+function defaultVersionMatcher (raw) {
+  // sanity check
+  if (ramda.isNil(raw) || ramda.isEmpty(raw)) return null
+
+  try {
+    // look for something that looks like semver
+    var rx = /([0-9]+\.[0-9]+\.[0-9]+)/
+    var match = ramda.match(rx, raw)
+    if (match.length > 0) {
+      return match[0]
+    } else {
+      return null
+    }
+  } catch (err) {
+    // something tragic happened
+    return false
+  }
+}
+
+/**
+ * Verifies the dependency which is installed is compatible with ignite.
+ *
+ * @param  {any}      opts                The options to enforce.
+ * @param  {boolean}  opts.optional       Is this an optional dependency?
+ * @param  {string}   opts.range          The semver range to test against.
+ * @param  {string}   opts.which          The command to run `which` on.
+ * @param  {string}   opts.versionCommand The command to run which returns text containing the version number.
+ * @param  {string}   opts.installMessage What to print should we fail.
+ * @param  {function} opts.versionMatcher A way to override the method to discover the version number.
+ * @return {boolean}                      `true` if we meet the requirements; otherwise `false`.
+ */
+function enforce (opts = {}) {
+  // opts to pass in
+  var optional = opts.optional || false
+  var range = opts.range
+  var which = opts.which
+  var versionCommand = opts.versionCommand
+  var installMessage = opts.installMessage
+  var versionMatcher = opts.versionMatcher || defaultVersionMatcher
+
+  /**
+   * Prints a friendly message that they don't meet the requirement.
+   *
+   * @param {string} installedVersion - current version if installed.
+   */
+  function printNotMetMessage (installedVersion) {
+    console.log('Ignite requires ' + which + ' ' + range + ' to be installed.')
+    if (installedVersion) {
+      console.log('')
+      console.log('You currently have ' + installedVersion + ' installed.')
+    }
+    console.log('')
+    console.log(installMessage)
+  }
+
+  /**
+   * Gets the version from the global dependency.
+   *
+   * @return {string} The version number or null.
+   */
+  function getVersion () {
+    // parse the version number
+    try {
+      // grab the raw output
+      var result = shell.exec(versionCommand, { silent: true })
+      var rawOut = ramda.trim(result.stdout || '')
+      var rawErr = ramda.trim(result.stderr || '') // java -version does this... grr
+
+      // assign the "right" one to raw
+      var raw = rawOut
+      if (ramda.isEmpty(raw)) {
+        raw = rawErr
+      }
+      if (ramda.isEmpty(raw)) {
+        raw = null
+      }
+
+      // and run it by the version matcher
+      return versionMatcher(raw)
+    } catch (err) {
+      return null
+    }
+  }
+
+  // are we installed?
+  var isInstalled = Boolean(shell.which(which))
+
+  if (!isInstalled) {
+    if (optional) {
+      return true
+    } else {
+      printNotMetMessage()
+      return false
+    }
+  }
+
+  // which version is installed?
+  try {
+    var installedVersion = getVersion()
+    var isMet = semver.satisfies(installedVersion, range)
+
+    // dependency has minimum met, we're good.
+    if (isMet) return true
+  } catch (err) {
+    // can't parse? just catch and we'll fallback to an error.
+  }
+
+  // o snap, time to upgrade
+  printNotMetMessage(installedVersion)
+  return false
+}
+
+module.exports = enforce

packages/ignite-cli/src/extensions/reactNative.js

@@ -56,18 +56,6 @@ function attach (plugin, command, context) {
       rnOptions.push('--skip-jest')
     }
 
-    // install React Native CLI if it isn't found
-    const rncliSpinner = print.spin(`checking react-native-cli`)
-    const cliInstalled = await system.which('react-native')
-    if (cliInstalled) {
-      rncliSpinner.stop()
-    } else {
-      // No React Native installed, let's get it
-      rncliSpinner.text = 'installing react-native-cli'
-      await system.run('npm install -g react-native-cli')
-      rncliSpinner.succeed(`installed react-native-cli`)
-    }
-
     // react-native init
     const cmd = trim(`react-native init ${name} ${rnOptions.join(' ')}`)
     log('initializing react native')

packages/ignite-cli/src/lib/exitCodes.js

@@ -60,5 +60,10 @@ module.exports = {
   /**
    * node_modules/react-native already exists.
    */
-  EXISTING_REACT_NATIVE: 11
+  EXISTING_REACT_NATIVE: 11,
+
+  /**
+   * One of the global dependencies are not met.
+   */
+  INVALID_GLOBAL_DEPENDENCY: 12
 }