@sap/eslint-plugin-cds/lib/rules/start-elements-lowercase.js

ESLint plugin including recommended SAP Cloud Application Programming model and environment rules

'use strict'

const { RULE_CATEGORIES } = require('../constants')

const allowedUpperCaseElements = ['ID']

module.exports = {
  meta: {
    schema: [{/* to avoid deprecation warning for ESLint 9 */}],
    docs: {
      category: RULE_CATEGORIES.model,
      description: 'Regular element names should start with lowercase letters.',
      url: 'https://cap.cloud.sap/docs/tools/cds-lint/rules/start-elements-lowercase',
    },
    type: 'suggestion',
    messages: {
      startLowercase: "Element name '{{defName}}:{{elementName}}' should start with a lowercase letter.",
    },
    fixable: 'code',
    model: 'parsed',
  },
  create: function (context) {
    const model = context.getModel()
    if (!model?.definitions)
      return

    return function checkAllElementsStartWithLowercase() {
      for (const defName in model.definitions)
        checkDefinition(defName, model.definitions[defName])
    }

    function checkDefinition(defName, def) {
      if (defName.startsWith('localized') || defName.endsWith('texts'))
        return

      checkElements(def)

      function checkElements(art) {
        if (art.elements) {
          for (const elementName in art.elements) {
            const element = art.elements[elementName]
            checkStartLowercase(element, elementName)
            checkElements(element)
          }
        }
      }

      function checkStartLowercase (element, elementName) {
        if (!element.$location?.file)
          return // without location, we can't report anything properly

        if (elementName.charAt(0) !== elementName.charAt(0).toLowerCase()
            && !allowedUpperCaseElements.includes(elementName)) {
          context.report({
            messageId: 'startLowercase',
            loc: context.getLocation(elementName, element),
            file: element.$location.file,
            data: {
              defName,
              elementName
            }
          })
        }
      }
    }
  }
}