splitster/src/clients/index.js

Javascript AB testing tool

import * as R from "ramda";

import { getTestsFromConfig } from "../records/test";
import { mergeDefaultConfig } from "../records/config";
import jsCookies from "js-cookie";

/**
 * Splitster client class abstraction
 * containing all the common methods
 */
export class SplitsterClient {
  // Config
  tests = {};
  options = {};

  // Live data
  user = "";
  userId = "";

  constructor({ config, user, userId, override = {} }, copy) {
    if (!config && !user && !userId && copy) {
      // Create new one from copy
      this.tests = copy.tests;
      this.options = copy.options;
      this.user = copy.user;
      this.results = copy.results;
      return;
    }

    try {
      if (
        !this.options.cookies.disabled &&
        !jsCookies.get("user_id_splitster")
      ) {
        // Save user_id to cookies
        jsCookies.set("user_id_splitster", this.userId);
      }
    } catch (err) {}

    // Initialize splitster

    // Set user
    this.user = user;
    this.userId = userId;
    // Set options
    this.options = config.options;

    this.tests = getTestsFromConfig(config.tests, { override, user, userId });
  }

  getSaveResults = (includeVersions? = false) =>
    R.compose(
      R.fromPairs,
      R.map(([testId, test]) => {
        const winning = test.disabled
          ? `__disabled_${test.disabledReason}`
          : test.winningVariant;
        return [
          includeVersions ? `${testId}_${test.version}` : testId,
          winning
        ];
      }),
      R.toPairs
    )(this.tests);

  get = testId => {
    if (!R.has(testId, this.tests)) {
      console.warn(
        `Splitster: Trying to access not existing test: ${testId}, your value will be null.`
      );
      return { value: null };
    }
    return { value: this.tests[testId].winningVariant };
  };

  set = (testId, variantId, cookie = false) => {
    try {
      if (cookie) {
        // Dev only for replacing also cookie.
        // You need to handle parsing by yourself in `override` object
        const cookieKey = `splitster_${testId}_${this.tests[testId].version}`;
        jsCookies.set(cookieKey, variantId);
      }
    } catch (err) {}

    return new SplitsterClient(
      {},
      {
        options: this.options,
        user: this.user,
        tests: R.assocPath([testId, "winningVariant"], variantId, this.tests)
      }
    );
  };
}

const init = (config, user, userId, override) => {
  const validConfig = mergeDefaultConfig(config);
  // TODO: in createValidConfig each test must me merged with test default config
  // also options should be merged
  return new SplitsterClient({ config: validConfig, user, userId, override });
};

export default init;