diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
index 839ccdaf..bd13accd 100644
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -4,22 +4,18 @@
     "customizations": {
         "vscode": {
             "extensions": [
-				"github.codespaces",
-                // PHP from https://github.com/devcontainers/templates/tree/main/src/php
-				"xdebug.php-debug",
-				"bmewburn.vscode-intelephense-client",
-				"xdebug.php-pack",
-                // PHP
-				"DEVSENSE.phptools-vscode",
-				"DEVSENSE.composer-php-vscode",
-                // linting
-				"EditorConfig.EditorConfig",
-				"dbaeumer.vscode-eslint",
-				"raymondcamden.CSSLint",
-                // testing
-				"maty.vscode-mocha-sidebar",
-                "recca0120.vscode-phpunit"
-			]
+                "github.codespaces",
+                "xdebug.php-debug",
+                "bmewburn.vscode-intelephense-client",
+                "xdebug.php-pack",
+                "DEVSENSE.phptools-vscode",
+                "DEVSENSE.composer-php-vscode",
+                "EditorConfig.EditorConfig",
+                "dbaeumer.vscode-eslint",
+                "raymondcamden.CSSLint",
+                "recca0120.vscode-phpunit",
+                "hbenl.vscode-mocha-test-adapter"
+            ]
         },
         "codespaces": {
             "openFiles": [
diff --git a/.devcontainer/postCreateCommand.sh b/.devcontainer/postCreateCommand.sh
index 269ecca3..ed9f7956 100755
--- a/.devcontainer/postCreateCommand.sh
+++ b/.devcontainer/postCreateCommand.sh
@@ -15,6 +15,10 @@ composer install --no-dev --optimize-autoloader
 composer global require phpunit/phpunit
 composer global require google/cloud-storage
 
-sudo chmod a+x "$(pwd)" && sudo rm -rf /var/www/html && sudo ln -s "$(pwd)" /var/www/html
-
+# for JS testing
+JAVASCRIPT_DIRECTORY="$(pwd)/js"
+npm --prefix "$JAVASCRIPT_DIRECTORY" install "$JAVASCRIPT_DIRECTORY"
 npm install --global nyc
+
+# development webserver
+sudo chmod a+x "$(pwd)" && sudo rm -rf /var/www/html && sudo ln -s "$(pwd)" /var/www/html
diff --git a/.vscode/extensions.json b/.vscode/extensions.json
index eea5315d..730e78eb 100644
--- a/.vscode/extensions.json
+++ b/.vscode/extensions.json
@@ -2,6 +2,7 @@
     "recommendations": [
         "recca0120.vscode-phpunit",
         "onecentlin.phpunit-snippets",
-        "devsense.profiler-php-vscode"
+        "devsense.profiler-php-vscode",
+        "spoonscen.es6-mocha-snippets"
     ]
 }
diff --git a/.vscode/settings.json b/.vscode/settings.json
index 08271210..f18b8d8b 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -8,5 +8,7 @@
         "${workspaceFolder}/tst/phpunit.xml",
         "--bootstrap",
         "${workspaceFolder}/tst/Bootstrap.php"
-    ]
+    ],
+    "mochaExplorer.pkgFile": "js/package.json",
+    "mochaExplorer.files": "js/test/*.js",
 }