prettier/src/parser.js

Prettier is an opinionated JavaScript formatter

"use strict";

function parseWithFlow(text, filename) {
  // Inline the require to avoid loading all the JS if we don't use it
  const flowParser = require("flow-parser");

  const ast = flowParser.parse(text, {
    esproposal_class_instance_fields: true,
    esproposal_class_static_fields: true,
    esproposal_export_star_as: true
  });

  if (ast.errors.length > 0) {
    let msg = ast.errors[0].message +
      " on line " +
      ast.errors[0].loc.start.line;
    if (filename) {
      msg += " in file " + filename;
    }
    throw new Error(msg);
  }

  return ast;
}

function parseWithBabylon(text) {
  // Inline the require to avoid loading all the JS if we don't use it
  const babylon = require("babylon");

  return babylon.parse(text, {
    sourceType: "module",
    allowImportExportEverywhere: false,
    allowReturnOutsideFunction: false,
    plugins: [
      "jsx",
      "flow",
      "doExpressions",
      "objectRestSpread",
      "decorators",
      "classProperties",
      "exportExtensions",
      "asyncGenerators",
      "functionBind",
      "functionSent",
      "dynamicImport"
    ]
  });
}

module.exports = {
  parseWithFlow,
  parseWithBabylon
};