Visual Console Client: improved the build system

Former-commit-id: ced96606af3fd36d2d77a2963df7ca70f4174d6e

visual_console/package.json

@@ -3,9 +3,12 @@
   "version": "1.0.0",
   "description": "Visual Console",
   "scripts": {
+    "clean-build": "node ./scripts/clean-build.js",
+    "prebuild": "npm run clean-build",
     "build": "NODE_ENV=production webpack",
-    "build:dev": "NODE_ENV=NODE_ENV=production  webpack",
-    "build:watch": "NODE_ENV=NODE_ENV=production  webpack --watch",
+    "prebuild:dev": "npm run clean-build",
+    "build:dev": "NODE_ENV=NODE_ENV=production webpack",
+    "build:watch": "NODE_ENV=NODE_ENV=production webpack --watch",
     "format": "prettier",
     "lint": "eslint \"src/**/*.ts\"",
     "start": "webpack-dev-server --color --mode=development",

visual_console/scripts/clean-build.js

@@ -0,0 +1,10 @@
+const path = require("path");
+const fs = require("fs");
+
+const buildPath = path.join(__dirname, "..", "build");
+
+if (fs.existsSync(buildPath)) {
+  fs.readdirSync(buildPath).forEach(file =>
+    fs.unlinkSync(path.join(buildPath, file))
+  );
+}

visual_console/webpack.config.js

@@ -6,7 +6,7 @@ module.exports = {
   mode: dev ? "development" : "production",
   entry: __dirname + "/src/index.ts", // Start from this file.
   output: {
-    path: __dirname + "/dist", // The files will be created here.
+    path: __dirname + "/build", // The files will be created here.
     filename: dev
       ? "visual-console-client.min.js"
       : "visual-console-client.[hash].min.js",