chore: fix missing fs bug

devenv.nix

@@ -21,6 +21,8 @@ in {
     (inputs.bob.packages."${builtins.currentSystem}".default)
 
     awscli2
+    graphviz
+    plantuml
     appimage-run
     blackbox
     coreutils-full
@@ -273,7 +275,11 @@ in {
     sed -i "1 i import \"./prepare.js\";"  ''${TEST_PATH}web/import.js
     sed -i "1 i /** this file was created automatically by the run-web-tests script */"  ''${TEST_PATH}web/import.js
 
-    npx esbuild --platform=browser --sourcemap=inline --external:ws --external:jsdom  --external:process --external:crypto --bundle ''${TEST_PATH}web/import.js --outfile=''${TEST_PATH}web/tests.js
+    if ! npx esbuild --platform=browser --sourcemap=inline --external:ws --external:jsdom --external:fs --external:fs --external:process --external:crypto --bundle ''${TEST_PATH}web/import.js --outfile=''${TEST_PATH}web/tests.js 
+    then
+      echo "ERROR: esbuild failed, check your JS!"
+      exit 1
+    fi
 
     sed -i '1s/^/try {\n/' ''${TEST_PATH}web/tests.js
     echo "} catch (e) {" >> ''${TEST_PATH}web/tests.js