From 7f783289abdb580022e2b73247c4d43e8e553ba4 Mon Sep 17 00:00:00 2001
From: Igor Minar <igor@angularjs.org>
Date: Sat, 14 Nov 2015 08:10:31 -0800
Subject: [PATCH] build: improve the environmental check and warnings

- we now correctly print errors even on old Node versions
- we print error messages even when node_modules are missing or messed up
- error messages looks better

Closes #5230
---
 gulpfile.js                |  8 ++++--
 tools/check-environment.js | 59 ++++++++++++++++++++++++++++++++------
 2 files changed, 56 insertions(+), 11 deletions(-)

diff --git a/gulpfile.js b/gulpfile.js
index b745570e31..cda5ac647e 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -1,5 +1,11 @@
 'use strict';
 
+// THIS CHECK SHOULD BE THE FIRST THING IN THIS FILE
+// This is to ensure that we catch env issues before we error while requiring other dependencies.
+require('./tools/check-environment')(
+    {requiredNpmVersion: '>=2.14.7 <3.0.0', requiredNodeVersion: '>=4.2.1 <5.0.0'});
+
+
 var del = require('del');
 var gulp = require('gulp');
 var gulpPlugins = require('gulp-load-plugins')();
@@ -26,8 +32,6 @@ var dartSdk = require('./tools/build/dart');
 var browserProvidersConf = require('./browser-providers.conf.js');
 
 
-require('./tools/check-environment')(
-    {requiredNpmVersion: '>=2.14.7', requiredNodeVersion: '>=4.2.1'});
 
 var cliArgs = minimist(process.argv.slice(2));
 
diff --git a/tools/check-environment.js b/tools/check-environment.js
index 16c473370d..b10be47f4c 100644
--- a/tools/check-environment.js
+++ b/tools/check-environment.js
@@ -1,7 +1,42 @@
-var exec = require('child_process').exec;
-var semver = require('semver');
+/* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+   !!!                                                                                   !!!
+   !!!  This file is special in that it must be able to execute with wrong Node version  !!!
+   !!!  or even when node_modules are missing.                                           !!!
+   !!!                                                                                   !!!
+   !!!  Do not depend on Node4+ features or presence of npm packages here.               !!!
+   !!!                                                                                   !!!
+   !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */
 
-var checkNodeModules = require('./npm/check-node-modules.js');
+'use strict';
+
+var exec = require('child_process').exec;
+var checkNodeModules;
+var semver;
+
+
+var issues = [];
+
+// coarse Node version check
+if (process.version[1] !== '4') {
+  issues.push("Angular 2 build currently requires Node 4. Use nvm to update your node version.");
+}
+
+try {
+  semver = require('semver');
+} catch(e) {
+  issues.push("Looks like you are missing some npm dependencies. Run: npm install");
+}
+
+// wrap in try/catch in case someone requires from within that file
+try {
+  checkNodeModules = require('./npm/check-node-modules.js');
+} catch(e) {
+  issues.push("Looks like you are missing some npm dependencies. Run: npm install");
+  throw e;
+} finally {
+  // print warnings and move on, the next steps will likely fail, but hey, we warned them.
+  printWarning(issues);
+}
 
 
 function checkEnvironment(reqs) {
@@ -26,14 +61,20 @@ function checkEnvironment(reqs) {
       issues.push('Your node_modules directory is stale or out of sync with npm-shrinkwrap.json. Run: npm install');
     }
 
-    if (issues.length) {
-      console.warn(Array(80).join('!'));
-      console.warn('Your environment is not in a good shape. Following issues were found:');
-      issues.forEach(function(issue) {console.warn('  - ' + issue)});
-      console.warn(Array(80).join('!'));
-    }
+    printWarning(issues);
   });
 }
 
+function printWarning(issues) {
+  if (!issues.length) return;
+
+  console.warn('');
+  console.warn(Array(110).join('!'));
+  console.warn('!!!  Your environment is not in a good shape. Following issues were found:');
+  issues.forEach(function(issue) {console.warn('!!!   - ' + issue)});
+  console.warn(Array(110).join('!'));
+  console.warn('');
+}
+
 
 module.exports = checkEnvironment;