#242: do not rebuild dlls, when they are up to date

scripts/build-dll.js

@@ -1,6 +1,8 @@
 /* eslint-env node */
 /* eslint-disable no-console */
 
+const fs = require('fs');
+
 const webpack = require('webpack');
 const chalk = require('chalk');
 
@@ -8,14 +10,59 @@ const webpackConfig = require('../webpack.dll.config.js');
 
 const compiler = webpack(webpackConfig);
 
-compiler.run(function(err, stats) {
-    if (err) {
-        console.error(chalk.red(err));
-        process.exit(1);
+Promise.all([
+    stat(__dirname + '/../npm-shrinkwrap.json'),
+    stat(__dirname + '/../dll/vendor.json')
+])
+.then(function(stats) {
+    const shrinkwrap = new Date(stats[0].mtime);
+    const dll = new Date(stats[1].mtime);
+
+    if (dll < shrinkwrap) {
+        return Promise.reject({
+            code: 'OUTDATED'
+        });
     }
 
-    console.error(
-        chalk.green('Dll was successfully build in %s ms'),
-        stats.endTime - stats.startTime
-    );
+    logResult(chalk.green('Current dlls are up to date!'));
+})
+.catch(function(err) {
+    if (err.code !== 'ENOENT' && err.code !== 'OUTDATED') {
+        return Promise.reject(err);
+    }
+
+    console.log('Rebuilding dlls...');
+
+    return new Promise(function(resolve, reject) {
+        compiler.run(function(err, stats) {
+            if (err) {
+                return reject(err);
+            }
+
+            logResult(
+                chalk.green('Dll was successfully build in %s ms'),
+                stats.endTime - stats.startTime
+            );
+
+            resolve();
+        });
+    });
+})
+.catch(function(err) {
+    logResult(chalk.red('Unexpected error checking dll state'), err);
+    process.exit(1);
 });
+
+function logResult() {
+    console.log('\n');
+    console.log.apply(console, arguments);
+    console.log('\n');
+}
+
+function stat(path) {
+    return new Promise(function(resolve, reject) {
+        fs.stat(path, function(err, stats) {
+            err ? reject(err) : resolve(stats);
+        });
+    });
+}