feat(cli): add skip-cleanup parameter

README.md

@@ -97,6 +97,7 @@ If those defaults do not work for you, the script accepts some arguments:
 - `--react-scripts-version`: expects the `react-scripts` version you are using in your project i.e `2.0.3`. If not given it will be implied from your `node_modules` and if it cannot be implied the version `2.1.2` will be the default. Consider setting it if you **ejected** and are not using the latest `react-scripts` version.
 - `-p|--public-path`: expects a relative URL where `/` is the root. If you serve your files using an external webserver this argument is to match with your web server configuration. More information can be found in [webpack configuration guide](https://webpack.js.org/configuration/output/#output-publicpath).
   - default: "".
+- `--skip-cleanup`: Skips the initial cleanup of the build folder. Could be beneficial when the cleanup is handled beforehand and some other files are moved to the build folder before running this script.
 - `-v|--verbose`: display webpack build output.
 
 # Contributions

scripts/index.js

@@ -21,6 +21,7 @@ const {
     chunkFilename,
     afterInitialBuildHook,
     afterRebuildHook,
+    skipCleanup,
   },
 } = require('../utils/cliHandler');
 const { getReactScriptsVersion, isEjected } = require('../utils');
@@ -129,49 +130,48 @@ config.plugins[htmlPluginIndex] = new HtmlWebpackPlugin({
 });
 
 spinner.succeed();
-spinner.start('Clear destination folder');
 
 let inProgress = false;
 
-fs.emptyDir(paths.appBuild)
-  .then(() => {
-    spinner.succeed();
-
-    return new Promise((resolve, reject) => {
-      const webpackCompiler = webpack(config);
-      new webpack.ProgressPlugin(() => {
-        if (!inProgress) {
-          spinner.start('Start webpack watch');
-          inProgress = true;
-        }
-      }).apply(webpackCompiler);
-
-      webpackCompiler.watch({}, (err, stats) => {
-        if (err) {
-          return reject(err);
-        }
-
-        spinner.succeed();
-
-        runHook('after rebuild hook', spinner, afterRebuildHook);
-
-        inProgress = false;
-
-        if (verbose) {
-          console.log();
-          console.log(
-            stats.toString({
-              chunks: false,
-              colors: true,
-            })
-          );
-          console.log();
-        }
-
-        return resolve();
-      });
-    });
-  })
+Promise.resolve()
+  .then(() => skipCleanup || clearDestinationFolder())
+  .then(
+    () =>
+      new Promise((resolve, reject) => {
+        const webpackCompiler = webpack(config);
+        new webpack.ProgressPlugin(() => {
+          if (!inProgress) {
+            spinner.start('Start webpack watch');
+            inProgress = true;
+          }
+        }).apply(webpackCompiler);
+
+        webpackCompiler.watch({}, (err, stats) => {
+          if (err) {
+            return reject(err);
+          }
+
+          spinner.succeed();
+
+          runHook('after rebuild hook', spinner, afterRebuildHook);
+
+          inProgress = false;
+
+          if (verbose) {
+            console.log();
+            console.log(
+              stats.toString({
+                chunks: false,
+                colors: true,
+              })
+            );
+            console.log();
+          }
+
+          return resolve();
+        });
+      })
+  )
   .then(() => copyPublicFolder())
   .then(() => runHook('after initial build hook', spinner, afterInitialBuildHook));
 
@@ -207,3 +207,8 @@ function handleBuildPath(userBuildPath) {
 
   return path.join(process.cwd(), userBuildPath);
 }
+
+function clearDestinationFolder() {
+  spinner.start('Clear destination folder');
+  return fs.emptyDir(paths.appBuild).then(() => spinner.succeed());
+}

utils/cliHandler.js

@@ -24,12 +24,15 @@ module.exports = meow(
 
       --react-scripts-version Version of the react-scripts package used in your project i.e 2.0.3. If not given it will be implied from your package.json and if it cannot be implied the major version 2 will be the default.
 
+      --skip-cleanup Skips the initial cleanup of the build folder. Could be beneficial when the cleanup is handled beforehand and some other files are moved to the build folder before running this script.
+
       -v, --verbose
 
     Examples
       $ cra-build-watch -b dist/ -p /assets
       $ cra-build-watch --chunk-filename './js/[chunkhash].[name]' -o './js/myapp'
       $ cra-build-watch -b dist/ -p /assets --chunk-filename './js/[name]/[hash].js' -v
+      $ cra-build-watch --skip-cleanup
 `,
   {
     flags: {
@@ -63,7 +66,10 @@ module.exports = meow(
       },
       'after-rebuild-hook': {
         type: 'string',
-      }
+      },
+      'skip-cleanup': {
+        type: 'boolean',
+      },
     },
   }
 );