The solution is to define an overrideConfigFile option to point to the location of the ESLint configuration file in the workspace in the settings.json like so:

{
    "eslint.options": { "overrideConfigFile": "./path/to/eslint.config.js" }
}

Since ESLint v8.x, the ESLint extension in VSCode uses the ESLint Class API to "[...] configure how ESLint is started". The extension documents that "[...] to point to a custom .eslintrc.json file using the new ESLint API" is as shown above.

For good measure, since the configuration file used is the new flat config file, the eslint.useFlatConfig setting can also be explicitly set to true. In the settings.json:

{
    "eslint.useFlatConfig": true
}

Since version 3.0.5 of the extension, the activation of this setting works like this:

• 8.57.0 <= ESLint version < 9.x: setting is honored and defaults to false.
• 9.0.0 <= ESLint version < 10.x: settings is honored and defaults to true.

You can add extension-level configuration in the VSCode settings.json file. Open this through the command palette:

• Press F1
• Type "user settings"
• Press Enter

Add the rules in eslint.options like this, according to the ESLint documentation:

// Place your settings in this file to overwrite the default settings
{
    "eslint.options": {
        "rules": {
            "quotes": [2, "double"]
        }
    }
}

You can add this to workspace-level configuration by opening "workspace settings" through the command palette. This will create a ./vscode/settings.json file in your project.

Hi @PaulHaze, the ESLint core team does not maintain the VSCode extension for ESLint. Please contact the maintainers there for more help.

When I have a root directory with multiple projects in, then it only looks for the config in the top level directory that is open, not in the root of the current project I am working on.

That's how the flat config system is designed. ESLint expects your config file to be in the root of the project and once it finds this file it stops searching for eslint.config.js files, unlike how it worked in the eslintrc config system where config files would be merged together. I believe the best way to solve this is to move all your individual ESLint configurations into a single root eslint.config.js and target specific project folders using the files key.

config file resolution doc
vscode-eslint

It was a node version issue. My distro only distributes the latest version of node. I've done the following for the errors to correct themselves.

1. Installed NVM

2. Set the version of node to 10.10.0

   $ nvm install 10.10.0
   $ nvm use 10.10.0
   

3. Inside the home/user/'Code - OSS'/User/settings.json file, added the following field to the JSON settings:

   {
     ...
     "eslint.runtime": "/home/user/.nvm/versions/node/v10.10.0/bin/node"  // This should be the path to the node runtime set by nvm
   }
   

4. After saving and restarting VSCode the errors were gone and ESLint is working correctly now.

NOTE: Check which version your system is using with nvm ls command. The output should look something like this

$ nvm ls
       v6.14.4
->     v10.10.0
       v10.20.0
       v12.16.2
default -> 10.10.0 (-> v10.10.0)
node -> stable (-> v12.16.2) (default)
stable -> 12.16 (-> v12.16.2) (default)
iojs -> N/A (default)
unstable -> N/A (default)
lts/* -> lts/erbium (-> v12.16.2)
lts/argon -> v4.9.1 (-> N/A)
lts/boron -> v6.17.1 (-> N/A)
lts/carbon -> v8.17.0 (-> N/A)
lts/dubnium -> v10.20.0
lts/erbium -> v12.16.2

Thank you for the help everyone. Sorry if the question did not give more relevant details as I did not have any clue on where the problem may lay, so I asked for assistance from a good friend who's experienced.

So I managed to solve this myself,

You need to specify in settings.json where the eslint.json file is. The code is

    "eslint.workingDirectories": [
    "./projectmt/"
] 

This got my linter working in vscode again, hope this helps someone in the future.

First, make sure you do not have the package installed globally. Then, set "eslint.nodePath" to the location of your node_modules directory that is parallel to the configuration directory.

1. yarn global remove eslint
2. "eslint.nodePath": "C:/.../node_modules"
3. open some files and look for "ESLint library loaded from:" in the Output window