@pega/custom-dx-components/src/rules/no-pcore-pconnect-in-presentation.js

Utility for building custom UI components

import fs from 'fs';
import path from 'path';

/** Cache: component directory → parsed config.json (or null) */
const configCache = new Map();

/**
 * Walks up the directory tree from `startDir` to find a `config.json` file,
 * stopping at the project root (`process.cwd()`) to avoid picking up unrelated configs.
 * Results are cached per directory to minimise repeated filesystem reads.
 */
function findComponentConfig(startDir) {
  if (configCache.has(startDir)) {
    return configCache.get(startDir);
  }

  const projectRoot = path.resolve(process.cwd());
  let dir = path.resolve(startDir);

  while (dir.startsWith(projectRoot)) {
    const candidate = path.join(dir, 'config.json');
    if (fs.existsSync(candidate)) {
      let parsed = null;
      try {
        parsed = JSON.parse(fs.readFileSync(candidate, 'utf8'));
      } catch {
        // ignore malformed config
      }
      configCache.set(startDir, parsed);
      return parsed;
    }
    const parent = path.dirname(dir);
    if (parent === dir) break;
    dir = parent;
  }

  configCache.set(startDir, null);
  return null;
}

/** @type {import('eslint').Rule.RuleModule} */
const rule = {
  meta: {
    type: 'problem',
    docs: {
      description: 'Disallow PCore and getPConnect usage in Presentation components',
      category: 'Pega DX Components',
      recommended: true
    },
    messages: {
      noPCore:
        'PCore must not be used in Presentation components (type="Presentation" in config.json). These are presentation-only components with no platform API access.',
      noGetPConnect:
        'getPConnect must not be used in Presentation components (type="Presentation" in config.json). These are presentation-only components with no platform API access.'
    },
    schema: []
  },

  create(context) {
    const filename = context.filename ?? context.getFilename();
    const fileDir = path.dirname(filename);
    const config = findComponentConfig(fileDir);

    if (!config || config.type !== 'Presentation') {
      return {};
    }

    return {
      // Flag `PCore` used as a standalone identifier (e.g. PCore.getConstants())
      Identifier(node) {
        if (node.name === 'PCore') {
          context.report({ node, messageId: 'noPCore' });
        }
      },

      // Flag `getPConnect` in destructuring: const { getPConnect } = props
      // and as a property access: props.getPConnect()
      Property(node) {
        if (node.key && node.key.name === 'getPConnect') {
          context.report({ node, messageId: 'noGetPConnect' });
        }
      },

      // Flag `getPConnect` as a member access: props.getPConnect or props['getPConnect']
      MemberExpression(node) {
        const prop = node.property;
        const isGetPConnect = node.computed ? prop.type === 'Literal' && prop.value === 'getPConnect' : prop.name === 'getPConnect';
        if (isGetPConnect) {
          context.report({ node, messageId: 'noGetPConnect' });
        }
      },

      // Flag `getPConnect` called directly as a standalone function: getPConnect()
      CallExpression(node) {
        if (node.callee.type === 'Identifier' && node.callee.name === 'getPConnect') {
          context.report({ node, messageId: 'noGetPConnect' });
        }
      }
    };
  }
};

export default rule;