Show hidden NodeModules folder in VSCode

To make the other answers more explicit, in order to unhide the node_modules contents for one project only, create a file named .vscode/settings.json in the project folder if it's not there yet and add these settings:

{
    "files.exclude": {
        "**/node_modules": false
    },
    "search.exclude": {
        "**/node_modules": false
    }
}

Note that the setting under "search.exclude" is required to re-include these files in the search, otherwise VSCode will inherit the "files.exclude" patterns defined in the user settings, which probably contain a line like "**/node_modules": true.

If you rather wish to unhide node_modules for all projects, open Preferences > Settings, be sure to select the User setting tab rather than the Workspace tab, then go to Text Editor > Files > Exclude and remove the line that contains node_modules.

Explorer View

If node_modules is hidden in your explorer view, then you probably have a pattern that's matching that directory in your settings. Go to settings, search for files.exclude and ensure that you haven't excluded the directory in user settings and/or workspace settings.

Search Results

If you want search results to include node_modules by default, you'll need to remove the pattern from the search.exclude setting. Note that search.exclude inherits all glob patterns from the files.exclude setting.

If you simply want specific searches to include node_modules, but don't want it included by default, there's a gear icon that you can toggle in the search view (go to the search view, toggle the search details using the ... icon, click the gear icon in the "files to exclude" input field).