From bd345861f5545a05778e988c9c0af9e220cf58dc Mon Sep 17 00:00:00 2001
From: Dawid Rusnak <dawid@drcode.pl>
Date: Mon, 12 Jun 2017 14:53:45 +0200
Subject: [PATCH] Fix linting, handle asynchronous virtual files

---
 index.js                                      | 17 +++++++++++----
 .../cases/contents-async/expected/file.txt    |  1 +
 .../integration/cases/contents-async/index.js |  4 ++++
 .../cases/contents-async/webpack.config.js    | 21 +++++++++++++++++++
 4 files changed, 39 insertions(+), 4 deletions(-)
 create mode 100644 test/integration/cases/contents-async/expected/file.txt
 create mode 100644 test/integration/cases/contents-async/index.js
 create mode 100644 test/integration/cases/contents-async/webpack.config.js

diff --git a/index.js b/index.js
index 2c95795..4c4bf15 100644
--- a/index.js
+++ b/index.js
@@ -22,7 +22,7 @@ class VirtualModulePlugin {
       contents = JSON.stringify(this.options.contents);
     }
     if (typeof this.options.contents === 'function') {
-      //call then function must be return string
+      // call then function must be return string
       contents = this.options.contents();
     }
 
@@ -39,10 +39,19 @@ class VirtualModulePlugin {
       if (!modulePath) {
         modulePath = this.join(compiler.context, moduleName);
       }
-      VirtualModulePlugin.populateFilesystem({ fs, modulePath, contents, ctime });
-      if (cb) {
-        cb();
+
+      const resolve = (data) => {
+        VirtualModulePlugin.populateFilesystem({ fs, modulePath, contents: data, ctime });
+      };
+
+      if (!cb) {
+        resolve(contents);
+        return;
       }
+
+      Promise.resolve(contents)
+        .then(resolve)
+        .then(cb);
     }
 
     if (!compiler.resolvers.normal) {
diff --git a/test/integration/cases/contents-async/expected/file.txt b/test/integration/cases/contents-async/expected/file.txt
new file mode 100644
index 0000000..2e65efe
--- /dev/null
+++ b/test/integration/cases/contents-async/expected/file.txt
@@ -0,0 +1 @@
+a
\ No newline at end of file
diff --git a/test/integration/cases/contents-async/index.js b/test/integration/cases/contents-async/index.js
new file mode 100644
index 0000000..f396679
--- /dev/null
+++ b/test/integration/cases/contents-async/index.js
@@ -0,0 +1,4 @@
+'use strict';
+
+// eslint-disable-next-line import/no-unresolved
+require('./a.txt');
diff --git a/test/integration/cases/contents-async/webpack.config.js b/test/integration/cases/contents-async/webpack.config.js
new file mode 100644
index 0000000..5c364a1
--- /dev/null
+++ b/test/integration/cases/contents-async/webpack.config.js
@@ -0,0 +1,21 @@
+'use strict';
+
+const ExtractTextPlugin = require('extract-text-webpack-plugin');
+const VirtualModulePlugin = require('../../../../index');
+
+function contents() {
+  return Promise.resolve('a');
+}
+
+module.exports = function webpackConfig() {
+  return {
+    entry: './index',
+    plugins: [
+      new VirtualModulePlugin({
+        moduleName: './a.txt',
+        contents,
+      }),
+      new ExtractTextPlugin('file.txt'),
+    ],
+  };
+};