NuxtJS module for A/B testing with Google Optimize

Note: Google Optimize is used for reporting (only).

• Main features
• Dependencies
• Setup
• Options
• Usage
• Credits
• License

• Run multiple experiments simultaneously
• TypeScript support
• Cookies to persist variants across users
• Event handlers ga or dataLayer
• Force a specific variant via url or param. E.g. url?gopt_experiment-x=1 or this.$abtest('experiment-x', true, 1);
• Avoid activating the a/b test anywhere. E.g. this.$abtest('experiment-x', false);
• Disable all a/b tests by cookie (gopt_disabled=1), which can be useful for E2E tests in CI/CD pipelines

You can choose one of the following options which injects Google Analytics into your application:

• analytics.js
• @nuxtjs/google-analytics
• 3rd-party such as Segment

1. Create a new experiment:

Name: Experiment X
Type of experience: A/B test

1. Add variants names:

Original: this.$abtest('my_experiment') = 0
Variant A: this.$abtest('my_experiment') = 1
Variant B: this.$abtest('my_experiment') = 2

1. Define a page targeting:

WHEN URL equals SERVER_SIDE

1. Define experiment's objectives.

1. Add nuxt-goptimize dependency to your project:

npm install nuxt-goptimize

1. Add nuxt-goptimize module and configuration to nuxt.config.js:

export default {
  // ...other config options
  modules: ["nuxt-goptimize"];
  googleOptimize: {
    experiments: '~/experiments.js', // optional
  }
}

1. Create the experiments.js in project's root with an array of your experiments. An example:

/**
 * {
 *  name: string; A name to identify the experiment on this.$abtest('NAME_HERE')
 *  id: string; Experiment ID of Google Optimize
 *  maxAgeDays: number; Number of days to persist the cookie of user's active variant
 *  variants: number[]; An array of variants weights
 * }
 */
module.exports = [
  {
    name: "experiment-x",
    id: "IUhKJR2MSTiPMVGAwJDFBL",
    maxAgeDays: 15,
    variants: [50, 50],
  },
];

1. (Optional) TypeScript support. Add nuxt-goptimize to the types section of tsconfig.json:

{
  "compilerOptions": {
    "types": ["nuxt-goptimize"]
  }
}

• Type: String
• Default: ~/experiments.js

File path for your experiments definition.

• Type: String
• Default: ga
• Values: ga, dataLayer

Event handler to let Google know about variants in-use.

It can be used inside components like:

{
  data: () => ({
    payBtnLabel: null as string | null,
    isScenarioA: true,
  }),
  mounted() {
    // Scenario: Determine an experiment variant and then display a label depending on it.
    const expA = this.$abtest('experiment-a');
    if (expA === 0) {
      this.payBtnLabel = 'Place order';
    } else {
      this.payBtnLabel = 'Pay now!';
    }

    // Scenario: We want to force a specific variant programmatically.
    const expB = this.$abtest('experiment-b', true, 1);
    console.log('expB is always 1');

    // Scenario: We have steps and we want to avoid activating the a/b test in any step
    // (meaning.. avoid assigning a variant and reporting it).
    const expC = this.$abtest('experiment-c', false)
    console.log('expC is always 0');
  }
}

• Brandon Mills for weightedRandom()

See the LICENSE file for license rights and limitations (MIT).