sort-default-props.js

/**
 * @fileoverview Enforce default props alphabetical sorting
 * @author Vladimir Kattsov
 */

'use strict';

const variableUtil = require('../util/variable');
const docsUrl = require('../util/docsUrl');
const propWrapperUtil = require('../util/propWrapper');

// ------------------------------------------------------------------------------
// Rule Definition
// ------------------------------------------------------------------------------

module.exports = {
  meta: {
    docs: {
      description: 'Enforce default props alphabetical sorting',
      category: 'Stylistic Issues',
      recommended: false,
      url: docsUrl('sort-default-props')
    },

    schema: [{
      type: 'object',
      properties: {
        ignoreCase: {
          type: 'boolean'
        }
      },
      additionalProperties: false
    }]
  },

  create(context) {
    const configuration = context.options[0] || {};
    const ignoreCase = configuration.ignoreCase || false;

    /**
     * Get properties name
     * @param {Object} node - Property.
     * @returns {String} Property name.
     */
    function getPropertyName(node) {
      if (node.key || ['MethodDefinition', 'Property'].indexOf(node.type) !== -1) {
        return node.key.name;
      }
      if (node.type === 'MemberExpression') {
        return node.property.name;
      // Special case for class properties
      // (babel-eslint@5 does not expose property name so we have to rely on tokens)
      }
      if (node.type === 'ClassProperty') {
        const tokens = context.getFirstTokens(node, 2);
        return tokens[1] && tokens[1].type === 'Identifier' ? tokens[1].value : tokens[0].value;
      }
      return '';
    }

    /**
     * Checks if the Identifier node passed in looks like a defaultProps declaration.
     * @param   {ASTNode}  node The node to check. Must be an Identifier node.
     * @returns {Boolean}       `true` if the node is a defaultProps declaration, `false` if not
     */
    function isDefaultPropsDeclaration(node) {
      const propName = getPropertyName(node);
      return (propName === 'defaultProps' || propName === 'getDefaultProps');
    }

    function getKey(node) {
      return context.getSourceCode().getText(node.key || node.argument);
    }

    /**
     * Find a variable by name in the current scope.
     * @param  {string} name Name of the variable to look for.
     * @returns {ASTNode|null} Return null if the variable could not be found, ASTNode otherwise.
     */
    function findVariableByName(name) {
      const variable = variableUtil.variablesInScope(context).find(item => item.name === name);

      if (!variable || !variable.defs[0] || !variable.defs[0].node) {
        return null;
      }

      if (variable.defs[0].node.type === 'TypeAlias') {
        return variable.defs[0].node.right;
      }

      return variable.defs[0].node.init;
    }

    /**
     * Checks if defaultProps declarations are sorted
     * @param {Array} declarations The array of AST nodes being checked.
     * @returns {void}
     */
    function checkSorted(declarations) {
      declarations.reduce((prev, curr, idx, decls) => {
        if (/Spread(?:Property|Element)$/.test(curr.type)) {
          return decls[idx + 1];
        }

        let prevPropName = getKey(prev);
        let currentPropName = getKey(curr);

        if (ignoreCase) {
          prevPropName = prevPropName.toLowerCase();
          currentPropName = currentPropName.toLowerCase();
        }

        if (currentPropName < prevPropName) {
          context.report({
            node: curr,
            message: 'Default prop types declarations should be sorted alphabetically'
          });

          return prev;
        }

        return curr;
      }, declarations[0]);
    }

    function checkNode(node) {
      switch (node && node.type) {
        case 'ObjectExpression':
          checkSorted(node.properties);
          break;
        case 'Identifier': {
          const propTypesObject = findVariableByName(node.name);
          if (propTypesObject && propTypesObject.properties) {
            checkSorted(propTypesObject.properties);
          }
          break;
        }
        case 'CallExpression': {
          const innerNode = node.arguments && node.arguments[0];
          if (propWrapperUtil.isPropWrapperFunction(context, node.callee.name) && innerNode) {
            checkNode(innerNode);
          }
          break;
        }
        default:
          break;
      }
    }

    // --------------------------------------------------------------------------
    // Public API
    // --------------------------------------------------------------------------

    return {
      ClassProperty(node) {
        if (!isDefaultPropsDeclaration(node)) {
          return;
        }

        checkNode(node.value);
      },

      MemberExpression(node) {
        if (!isDefaultPropsDeclaration(node)) {
          return;
        }

        checkNode(node.parent.right);
      }
    };
  }
};