eslint-plugin-grapes/rules/no-internal-import.js

A one-rule ESLint plugin to corral your file structure.

const fs = require("fs");
const path = require("path");
const IMPORT_PREFIX = /(\.\.\/)+|(\.\/)+/;
const BAD_IMPORT_REGEX = /(\.{1,2}\/)\w+\//g;
const INDEX_FILE_REGEX = /^index\.(j|t)sx?$/g;

const importIsModule = (importPath, contextPath, indexRegex) => {
  const prefix = importPath.match(IMPORT_PREFIX)[0];
  const pathSuffix = importPath.replace(prefix, "");
  const split = pathSuffix.split("/");
  while (split.length > 1) {
    split.pop();
    const me = path.parse(contextPath);
    const it = prefix + split.join(path.sep);
    const resolvedPath = path.resolve(me.dir, it);
    try {
      const files = fs.readdirSync(resolvedPath);
      const hasIndexFile = files.some((file) => {
        const match = file.match(indexRegex);
        return !!match;
      });
      if (hasIndexFile) return true;
    } catch {
      return true;
    }
  }
};

const create = function (context) {
  let indexRegex = INDEX_FILE_REGEX;
  const options = context.options || [];
  if(options.length > 0){
    const {indexFileRegex} = options[0];
    indexRegex = new RegExp(indexFileRegex);
  }
  return {
    ImportDeclaration(node) {
      if (!node || !node.source || !node.source.value) return;
      const importPath = node.source.value;
      if (!importPath.match(BAD_IMPORT_REGEX)) return;
      
      const isModule = importIsModule(
        importPath,
        context.getFilename(),
        indexRegex
      );

      if (isModule) {
        context.report({
          node,
          message:
            "Do not import another module's internal files or functionality.",
        });
      }
    },
  };
};

const meta = {
  type: "suggestion",
  docs: {
    description:
      'You should not access another "unit"\'s internal files or functions.',
    category: "Best Practices",
    recommended: true,
  },
  schema: [
    {
      type: "object",
      properties: {
        indexFileRegex: {
          type: "string",
          title: "Index file regex",
          description:
            'The regex used to determine what constitutes an "index" file',
          default: "^index\\.(j|t)sx?$",
        },
      },
      additionalProperties: false,
    },
  ],
};

module.exports = {
  create,
  meta,
};