@razee/mustachetemplate/src/handlebar-helpers.js

Razee: component to use the Mustache template processor on kubernetes resource configurations.

// list of useful handlebars helpers we can bundle
// credit goes to https://stackoverflow.com/a/31632215 & https://stackoverflow.com/a/50427569
//
// TODO: maybe make this extensible via another CR field?

const objectPath = require('object-path');
const crypto = require('crypto');

const helpers = {
  assign: function (varName, varValue, options) {
    if (!objectPath.has(options, 'data.root')) {
      objectPath.set(options, 'data.root', {});
    }
    objectPath.set(options, ['data', 'root', varName], varValue);
  },
  eq: (v1, v2) => v1 === v2,
  ne: (v1, v2) => v1 !== v2,
  lt: (v1, v2) => v1 < v2,
  gt: (v1, v2) => v1 > v2,
  lte: (v1, v2) => v1 <= v2,
  gte: (v1, v2) => v1 >= v2,
  and(...args) {
    return args.every(Boolean);
  },
  or(...args) {
    return args.slice(0, -1).some(Boolean);
  },
  split: function (data, delimiter) {
    if (typeof data === 'string' && typeof delimiter === 'string') {
      return data.split(delimiter);
    }
    return [data];
  },
  divide: function (x, y) {
    if (typeof x === 'number' && typeof y === 'number' && y !== 0) {
      return parseInt(x / y);
    } else {
      return -1;
    }
  },
  add: function (x, y) {
    if (typeof x === 'number' && typeof y === 'number') {
      return x + y;
    }
    return -1;
  },
  substring: function (data, startIndex, endIndex) {
    startIndex = (typeof startIndex === 'number') ? startIndex : undefined;
    endIndex = (typeof endIndex === 'number') ? endIndex : undefined;
    if (typeof data === 'string') {
      return data.substring(startIndex, endIndex);
    }
    return data;
  },
  includes: function (arr, valueToFind, fromIndex) {
    fromIndex = (typeof fromIndex === 'number') ? fromIndex : undefined;
    if (Array.isArray(arr) && valueToFind !== 'undefined') {
      return arr.includes(valueToFind, fromIndex);
    }
    return false;
  },
  sha256: function (data) {
    if (typeof data !== 'string') {
      return '';
    }
    const hash = crypto.createHash('sha256').update(data).digest('hex');
    return hash;
  },
  concat: function (...arr) {
    arr.pop();
    let flat = arr.flat();
    return ''.concat(...flat);
  },
  base64: function (data) {
    if (typeof data !== 'string' && !Array.isArray(data)) {
      return '';
    }
    return Buffer.from(data).toString('base64');
  },
  jsonStringify: function (data, space, indent = 0) {
    return JSON.stringify(data, null, space).replace(/\n/g, '\n'+' '.repeat(indent));
  },
  jsonDoubleStringify: function (data, space) {
    // if you want to use this, you must use our strTemplate, and you must not put quotes around your template (ie. `my-field: {{ jsonStringify my-json }}` is valid but `my-field: "{{ jsonStringify my-json }}"` is not)
    return JSON.stringify(JSON.stringify(data, null, space));
  },
  pick: function (...args) {
    return args.find((value) => {
      if (value === null) return false;
      if (value === undefined) return false;
      if (value === '') return false;
      return true;
    });
  },
  startswith: function(str, ...args) {
    if (typeof str !== 'string') return false;
    return args.some((arg) => {
      return str.startsWith(arg);
    });
  },
  endswith: function(str, ...args) {
    if (typeof str !== 'string') return false;
    return args.some((arg) => {
      return str.endsWith(arg);
    });
  },
  lower: function(str) {
    if (typeof str !== 'string') return str;
    return str.toLowerCase();
  },
  upper: function(str) {
    if (typeof str !== 'string') return str;
    return str.toUpperCase();
  }
};

module.exports = helpers;