@comyata/run/Expr.js

Simplify data workflows and management with data templates, for browser and server.

import jsonata from 'jsonata';
export function toExpr(expr, functions = jsonataExtraFunctions) {
  const exprEval = jsonata(expr, {
    recover: false
  });
  exprEval.registerFunction('coalesce', (...args) => args.find(arg => typeof arg !== 'undefined' && arg !== null));
  for (const fn of functions) {
    exprEval.registerFunction(fn.name, fn.fn, fn.signature);
  }
  return exprEval;
}
export const jsonataExtraFunctions = [{
  name: 'repeat',
  fn: (str, count) => str.repeat(count),
  signature: '<sn:s>'
}, {
  name: 'some',
  fn: async function (arr, test) {
    if (!arr) return false;
    for (const item of arr) {
      const r = await test.apply(this, [item]);
      if (r) return true;
    }
    return false;
  },
  signature: '<(al)f:b>'
}, {
  name: 'toJSON',
  fn: value => JSON.stringify(value),
  signature: '<j:s>'
}, {
  name: 'fromJSON',
  fn: text => JSON.parse(text),
  signature: '<s:j>'
}, {
  name: 'isNaN',
  fn: text => Number.isNaN(Number(text)),
  signature: '<(sn):b>'
}];