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no-schema-enum

Disallow enum in settings JSON schema files; use oneOf with const and title instead.

Why​

In JupyterLab/Notebook v7+, using enum in a settings JSON schema prevents associating user-facing labels with values and makes the options untranslatable. The oneOf pattern with const and title per entry solves both problems: the title is what the user sees, and the const is the value stored — and title can be passed through the translation system.

Rule details​

The rule inspects JSON files located inside a schema/ directory and reports any property named "enum" whose value is an array. It does not flag enum used with a non-array value, and it ignores JSON files outside of schema/ directories.

Requires jsonc-eslint-parser (v2) to be configured as the parser for JSON files.

Incorrect​

{
  "properties": {
    "defaultZoom": {
      "type": "string",
      "enum": ["fit-to-width", "fit-to-height", "100%"]
    }
  }
}

Correct​

{
  "properties": {
    "defaultZoom": {
      "oneOf": [
        { "const": "fit-to-width",  "title": "Fit to width"  },
        { "const": "fit-to-height", "title": "Fit to height" },
        { "const": "100%",          "title": "100%"          }
      ]
    }
  }
}

Options​

This rule has no options.

Configuration​

Add the rule to your ESLint flat config for schema JSON files:

import * as jsoncParser from 'jsonc-eslint-parser';
import jupyterPlugin from '@jupyter/eslint-plugin';

export default [
  {
    files: ['**/schema/*.json'],
    languageOptions: { parser: jsoncParser },
    plugins: { jupyter: jupyterPlugin },
    rules: {
      'jupyter/no-schema-enum': 'error'
    }
  }
];