@sap/eslint-plugin-cds/lib/rules/sql-cast-suggestion.js

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

'use strict'

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

module.exports = {
  meta: {
    schema: [{/* to avoid deprecation warning for ESLint 9 */}],
    docs: {
      category: RULE_CATEGORIES.model,
      description: 'Should make suggestions for possible missing SQL casts.',
      recommended: true,
      url: 'https://cap.cloud.sap/docs/tools/cds-lint/rules/sql-cast-suggestion',
    },
    type: 'suggestion',
    messages: {
      missingSqlCast: 'Potential issue - Missing SQL cast for column expression?'
    },
    model: 'parsed',
  },
  create: function (context) {
    const model = context.getModel()
    if (!model?.definitions)
      return

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

    function checkSqlCastsInView(defName, def) {
      // TODO: restructure and make more robust (#507)
      if (!def?.query?.SET?.args?.length)
        return

      for (const arg of def.query.SET.args) {
        if (arg?.SELECT?.columns?.length) {
          // Only in UNION cases?
          for (const col of arg.SELECT.columns) {
            if (col)
              checkColumn(col)
          }
        }
      }

      function checkColumn(col) {
        const { xpr, cast } = col
        if (cast && xpr) {
          if (!(xpr[0]?.xpr && xpr[0]?.cast)) {
            // we don't pass a name for the column's location, as it would be used to calculate
            // endColumn, which is not correct for this expression
            const loc = col.$location ?
              context.getLocation('', col, model) :
              context.getLocation(defName, def, model)

            context.report({
              messageId: 'missingSqlCast',
              loc,
              file: def.$location.file,
            })
          }
        }
      }
    }
  }
}