🐛 Format on save lint fixes garble the file

[valeneiko]

VS Code version

1.90.1

Extension version

2.3.0

Biome version

1.8.1

Operating system

• Windows
• macOS
• Linux

Description

Format on save produces wrong output when multiple fixes for the same lint rule are applied to the same expression.

Steps to reproduce

1. A biome.json config with linter enabled:

   // biome.json
   {
     "$schema": "./node_modules/@biomejs/biome/configuration_schema.json",
     "files": {
       "include": ["*.ts", "*.json"]
     },
     "formatter": {
       "enabled": false
     },
     "linter": {
       "enabled": true
     },
     "organizeImports": {
       "enabled": false
     }
   }

2. Create a TS file where lint/complexity/useFlatMap fails multiple times on the same expression:

   // index.ts
   Object.values(rules.lints.languages)
     .map((l) => Object.values(l))
     .flat()
     .map((l) => Object.values(l))
     .flat();

3. Configure VSCode to format on save:

   // .vscode/settings.json
   {
     "editor.formatOnSave": true,
     "editor.codeActionsOnSave": {
       "quickfix.biome": "explicit"
     },
     "[typescript]": {
       "editor.defaultFormatter": "biomejs.biome"
     }
   }

4. Save the file and observe the wrong output:

   // index.ts
   Object.values(rules.lints.languages)
     .flatMap((l) => Object.values(l))
     .map((l) => Object.values(l))
     .flatMapt();

Expected behavior

Lint rule fixes to be correctly applied on save:

// index.ts
Object.values(rules.lints.languages)
  .flatMap((l) => Object.values(l))
  .flatMap((l) => Object.values(l));

Does this issue occur when using the CLI directly?

No

Logs

No response

[Sec-ant]

I believe this is a duplicate of biomejs/biome#2268 and biomejs/biome#1570. Thanks for providing the example code.