@sap/eslint-plugin-cds/lib/rules/js/no-cross-service-import.js

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

'use strict'

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

// used as a pre-check to ensure the checks using RegExps
// with greedy matchers are not susceptible to ReDoS attacks
const MAX_INPUT_STRING_LENGTH = 1_000

/**
 * @param {string} importPath
 * @param {RuleContext} context
 * @param {Node} node
 */
function compareImportAndFilename (importPath, context, node) {
  const currentFile = context.getFilename()
  // ignore stdin
  if (currentFile === '<input>') return
  // ignore excessively long strings
  if (importPath.length > MAX_INPUT_STRING_LENGTH || currentFile.length > MAX_INPUT_STRING_LENGTH) return
  const [, typerModuleFq, typerModule] = /^#cds-models\/.*?((\w+)Service)$/.exec(importPath) ?? []
  const [, fileNameFq, fileName] = /((\w+)-?[sS]ervice\.m?[jt]s)$/.exec(currentFile)
  // typerModule === undefined -> not a service import (probably db-level-entity import)
  if (typerModule && fileName && typerModule !== fileName) {
    context.report({
      node,
      messageId: 'noCrossServiceImport',
      data: {
        from: typerModuleFq,
        target: fileNameFq
      }
    })
  }
}

module.exports = {
  meta: {
    type: 'problem',
    docs: {
      recommended: true,
      category: RULE_CATEGORIES.javascript,
      description: 'Warn about imports from another service.'
    },
    schema: [],
    messages: {
      noCrossServiceImport: 'You are importing service-level entities from another service "{{from}}" inside the definition of service "{{target}}". This is likely an accidental cross-service import.',
    },
    hasSuggestions: false
  },
  create: context => ({
    CallExpression(node) {
      // look for: require('#cds-models/...')
      if (node.callee.type !== 'Identifier') return
      if (node.callee.name !== 'require') return
      if (node.arguments.length !== 1) return
      if (node.arguments[0].type !== 'Literal') return
      compareImportAndFilename(node.arguments[0].value, context, node)
    },

    ImportDeclaration(node) {
      // import ... from '#cds-models/...'
      compareImportAndFilename(node.source.value, context, node)
    },

    ImportExpression(node) {
      // await import('#cds-models/...')
      compareImportAndFilename(node.source.value, context, node)
    }
  })
}