build(gulp): check node and npm version and log a warning if incompatible

Closes #1758

gulpfile.js

@@ -3,6 +3,7 @@
 var autoprefixer = require('gulp-autoprefixer');
 var del = require('del');
 var format = require('gulp-clang-format');
+var exec = require('child_process').exec;
 var fork = require('child_process').fork;
 var gulp = require('gulp');
 var gulpPlugins = require('gulp-load-plugins')();
@@ -13,6 +14,7 @@ var madge = require('madge');
 var merge = require('merge');
 var merge2 = require('merge2');
 var path = require('path');
+var semver = require('semver');
 var watch = require('gulp-watch');
 
 var clean = require('./tools/build/clean');
@@ -49,8 +51,37 @@ var angularBuilder = {
   cleanup: function() {}
 };
 
-// Note: when DART_SDK is not found, all gulp tasks ending with `.dart` will be skipped.
+(function checkNodeAndNpmVersions() {
+  var requiredNpmVersion = '>=2.9.0';
+  var requiredNodeVersion = '>=0.10.x'; // TODO: bump this to 0.12 once travis runs on 0.12
 
+  exec('npm --version', function(e, stdout) {
+    var foundNpmVersion = semver.clean(stdout);
+    var foundNodeVersion = process.version;
+    var issues = [];
+
+
+    if (!semver.satisfies(foundNodeVersion, requiredNodeVersion)) {
+      issues.push('You are running unsupported node version. Found: ' + foundNodeVersion +
+        ' Expected: ' + requiredNodeVersion);
+    }
+
+    if (!semver.satisfies(foundNpmVersion, requiredNpmVersion)) {
+      issues.push('You are running unsuported npm version. Found: ' + foundNpmVersion +
+        ' Expected: ' + requiredNpmVersion);
+    }
+
+    if (issues.length) {
+      // TODO: in the future we should error, but let's just display the warning for a few days first
+      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('!'));
+    }
+  });
+}())
+
+// Note: when DART_SDK is not found, all gulp tasks ending with `.dart` will be skipped.
 var DART_SDK = require('./tools/build/dartdetect')(gulp);
 
 // -----------------------

npm-shrinkwrap.clean.json

@@ -8382,6 +8382,9 @@
         }
       }
     },
+    "semver": {
+      "version": "4.3.4"
+    },
     "sorted-object": {
       "version": "1.0.0"
     },

npm-shrinkwrap.json

@@ -12951,6 +12951,11 @@
         }
       }
     },
+    "semver": {
+      "version": "4.3.4",
+      "from": "semver@*",
+      "resolved": "https://registry.npmjs.org/semver/-/semver-4.3.4.tgz"
+    },
     "sorted-object": {
       "version": "1.0.0",
       "from": "https://registry.npmjs.org/sorted-object/-/sorted-object-1.0.0.tgz",

package.json

@@ -100,6 +100,7 @@
     "q": "^1.0.1",
     "react": "^0.13.2",
     "run-sequence": "^0.3.6",
+    "semver": "^4.3.4",
     "sorted-object": "^1.0.0",
     "source-map": "^0.3.0",
     "sprintf-js": "1.0.*",