feat(SASS/LESS): Add warnings when required dependencies are missing

blueprints/ember-bootstrap/index.js

@@ -2,6 +2,7 @@ const rsvp = require('rsvp');
 const fs = require('fs');
 const path = require('path');
 const writeFile = rsvp.denodeify(fs.writeFile);
+const chalk = require('chalk');
 
 const bs3Version = '^3.3.7';
 
@@ -48,10 +49,10 @@ module.exports = {
         fs.mkdirSync(stylePath);
       }
       if (fs.existsSync(file)) {
-        this.ui.writeLine(`Added import statement to ${file}`);
+        this.ui.writeLine(chalk.green(`Added import statement to ${file}`));
         return this.insertIntoFile(file, importStatement, {});
       } else {
-        this.ui.writeLine(`Created ${file}`);
+        this.ui.writeLine(chalk.green(`Created ${file}`));
         return writeFile(file, importStatement);
       }
     }

index.js

@@ -9,6 +9,7 @@ const Funnel = require('broccoli-funnel');
 const stew = require('broccoli-stew');
 // const mv = stew.mv;
 // const rm = stew.rm;
+const chalk = require('chalk');
 
 const defaultOptions = {
   importBootstrapTheme: false,
@@ -56,7 +57,27 @@ module.exports = {
   },
 
   findPreprocessor() {
-    return supportedPreprocessors.find((name) => !!this.app.project.findAddonByName(`ember-cli-${name}`));
+    return supportedPreprocessors.find((name) => !!this.app.project.findAddonByName(`ember-cli-${name}`) && this.validatePreprocessor(name));
+  },
+
+  validatePreprocessor(name) {
+    let npmDependencies = this.app.project.dependencies();
+    let bowerDependencies = this.app.project.bowerDependencies();
+    switch (name) {
+      case 'sass':
+        if (!('bootstrap-sass' in npmDependencies)) {
+          this.ui.writeLine(chalk.red('Npm package "bootstrap-sass" is missing, but required for SASS support. Please run `ember generate ember-bootstrap` to install the missing dependencies!'));
+          return false;
+        }
+        break;
+      case 'less':
+        if (!('bootstrap' in bowerDependencies)) {
+          this.ui.writeLine(chalk.red('Bower package "bootstrap" is missing, but required for Less support. Please run `ember generate ember-bootstrap` to install the missing dependencies!'));
+          return false;
+        }
+        break;
+    }
+    return true;
   },
 
   getBootstrapStylesPath() {

package.json

@@ -73,6 +73,7 @@
     "broccoli-funnel": "^1.0.1",
     "broccoli-merge-trees": "^1.1.1",
     "broccoli-stew": "^1.4.0",
+    "chalk": "^1.1.3",
     "ember-cli-babel": "^5.1.7",
     "ember-cli-htmlbars": "^1.0.10",
     "ember-runtime-enumerable-includes-polyfill": "^1.0.1",