Fix comparison tests under WSL (#1109)

* Ensure a separate webpack instance is created if different loader options are used
Add execution test for this behaviour

* Fix import order (lint error)

* Update version to 7.04 and include in changelog

* Tweak to Changelog

* Add a delay before starting the comparison tests

* Update pull request number in changelog

* Add comments to link to pull request

Co-authored-by: John Reilly <johnny_reilly@hotmail.com>

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Changelog
 
 ## v7.0.5
+* [Add a delay before starting the comparison tests to avoid failures under WSL](https://github.com/TypeStrong/ts-loader/pull/1109) - thanks @appzuka
 * [Apply other loaders when updating files in watch mode](https://github.com/TypeStrong/ts-loader/pull/1115) - thanks @iorate
 
 ## v7.0.4

test/comparison-tests/create-and-execute-test.js

@@ -109,10 +109,16 @@ function createTest(test, testPath, options) {
         mkdirp.sync(paths.actualOutput);
         mkdirp.sync(paths.webpackOutput);
 
-        // execute webpack
-        testState.watcher = webpack(
-            createWebpackConfig(paths, options, nonWatchNonCompositePath !== testPath)
-        ).watch({ aggregateTimeout: 1500 }, createWebpackWatchHandler(done, paths, testState, options, test));
+
+        // Need to wait > FS_ACCURACY as defined in watchpack.
+        // See PR 1109 for details: https://github.com/TypeStrong/ts-loader/pull/1109
+        setTimeout(() => {
+            // execute webpack
+            testState.watcher = webpack(
+                createWebpackConfig(paths, options, nonWatchNonCompositePath !== testPath)
+            ).watch({ aggregateTimeout: 1500 }, createWebpackWatchHandler(done, paths, testState, options, test));
+        }, 200);
+
     };
 }
 
@@ -275,6 +281,7 @@ function copyPatchOrEndTest(testStagingPath, watcher, testState, done) {
     if (fs.existsSync(patchPath)) {
         testState.iteration++;
         // can get inconsistent results if copying right away
+        // Probably due to the reaons in PR 1109: https://github.com/TypeStrong/ts-loader/pull/1109
         setTimeout(function () {
             copySync(patchPath, testStagingPath);
         }, 1000);