fix(v2): wait plugin watching approach (#1390)

* fix(v2): wait plugin watching approach

* Update package.json

* rush fix

* Use 2. x branch

* Update WaitPlugin.js

* yarn.lock

* use polling

* switch chokidar w-> wait-on npm package

packages/docusaurus/lib/webpack/plugins/WaitPlugin.js

@@ -5,8 +5,9 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-const fs = require('fs');
-const chokidar = require('chokidar');
+const path = require('path');
+const fs = require('fs-extra');
+const waitOn = require('wait-on');
 
 class WaitPlugin {
   constructor(options) {
@@ -16,18 +17,20 @@ class WaitPlugin {
   apply(compiler) {
     // Before finishing the compilation step
     compiler.hooks.make.tapAsync('WaitPlugin', (compilation, callback) => {
-      const {filepath} = this;
-      const watcher = chokidar.watch(filepath, {
-        awaitWriteFinish: true,
-        disableGlobbing: true,
-      });
+      // To prevent 'waitOn' error on waiting non-existing directory
+      fs.ensureDirSync(path.dirname(this.filepath));
 
-      watcher.on('add', () => {
-        if (fs.existsSync(filepath)) {
-          watcher.close();
+      // Wait until file exist
+      waitOn({
+        resources: [this.filepath],
+        interval: 300,
+      })
+        .then(() => {
           callback();
-        }
-      });
+        })
+        .catch(error => {
+          console.warn(`WaitPlugin error: ${error}`);
+        });
     });
   }
 }

packages/docusaurus/package.json

@@ -68,6 +68,7 @@
     "static-site-generator-webpack-plugin": "^3.4.2",
     "style-loader": "^0.22.1",
     "terser-webpack-plugin": "^1.2.3",
+    "wait-on": "^3.2.0",
     "webpack": "^4.29.6",
     "webpack-bundle-analyzer": "^3.1.0",
     "webpack-dev-server": "^3.2.1",