fix: parallel on wsl

azure-pipelines.yml

@@ -190,3 +190,54 @@ jobs:
       - script: curl -s https://codecov.io/bash | bash -s -- -t $(CODECOV_TOKEN)
         condition: succeededOrFailed()
         displayName: 'Submit coverage data to codecov'
+
+  # WSL
+  - job: WSL
+    pool:
+      vmImage: windows-2019
+    strategy:
+      maxParallel: 4
+      matrix:
+        node-8:
+          node_version: ^8.9.0
+          webpack_version: latest
+    steps:
+      - powershell: |
+          choco install wsl-ubuntu-1804
+          wsl -l -v
+        displayName: 'Install WSL'
+        runAsRoot: true
+      - script: 'git config --global core.autocrlf input'
+        displayName: 'Config git core.autocrlf'
+      - checkout: self
+      - task: NodeTool@0
+        inputs:
+          versionSpec: $(node_version)
+        displayName: 'Install Node.js $(node_version)'
+      - task: Npm@1
+        inputs:
+          command: custom
+          customCommand: i -g npm@latest
+        displayName: 'Install latest NPM'
+      - script: |
+          node -v
+          npm -v
+        displayName: 'Print versions'
+      - task: Npm@1
+        inputs:
+          command: custom
+          customCommand: ci
+        displayName: 'Install dependencies'
+      - script: npm i webpack@$(webpack_version)
+        displayName: 'Install "webpack@$(webpack_version)"'
+      - script: npm run test:coverage -- --ci --reporters="default" --reporters="jest-junit" || $(continue_on_error)
+        displayName: 'Run tests with coverage'
+      - task: PublishTestResults@2
+        inputs:
+          testRunTitle: 'Linux with Node.js $(node_version)'
+          testResultsFiles: '**/junit.xml'
+        condition: succeededOrFailed()
+        displayName: 'Publish test results'
+      - script: curl -s https://codecov.io/bash | bash -s -- -t $(CODECOV_TOKEN)
+        condition: succeededOrFailed()
+        displayName: 'Submit coverage data to codecov'

package.json

@@ -39,7 +39,6 @@
   "dependencies": {
     "cacache": "^12.0.3",
     "find-cache-dir": "^3.0.0",
-    "is-wsl": "^2.1.0",
     "jest-worker": "^24.9.0",
     "schema-utils": "^2.2.0",
     "serialize-javascript": "^2.1.0",

src/TaskRunner.js

@@ -4,7 +4,6 @@ import cacache from 'cacache';
 import findCacheDir from 'find-cache-dir';
 import Worker from 'jest-worker';
 import serialize from 'serialize-javascript';
-import isWsl from 'is-wsl';
 
 import minify from './minify';
 
@@ -28,11 +27,7 @@ export default class TaskRunner {
     // https://github.com/nodejs/node/issues/19022
     const cpus = os.cpus() || { length: 1 };
 
-    // WSL sometimes freezes, error seems to be on the WSL side
-    // https://github.com/webpack-contrib/terser-webpack-plugin/issues/21
-    return isWsl
-      ? 1
-      : parallel === true
+    return parallel === true
       ? cpus.length - 1
       : Math.min(Number(parallel) || 0, cpus.length - 1);
   }