Adding & testing custom scripts

Introduction

This page explains how to add a custom script for payload transformations. You will create a new script, add your code using IntelliSense, and then save changes ready for testing. Adding a new custom script can be broken down into three distinct stages:

1. Create a new script

2. Add script code

3. Test script code

This page walks through creating and testing a new script. We'll be adding a Javascript (node 18) script to change email addresses in a given payload to [email protected]. If you'd like to try this yourself, our script and test payload are available below.

Sample script & test payload

Script code (javascript node 18)

module.exports = async function (data) {
    const payload = JSON. parse (data.payload);

   if (payload.customers) {
     payload.customers.forEach(customer => {
         customer.email = '[email protected]';
      })
    }

    return { "payload": JSON.stringify(payload) };
};

Test payload (customers)

[
    {
        "id": 1000000001,
        "first_name": "Britney",
        "last_name": "Spears",
        "email": "[email protected]"
    },
    {
        "id": 1000000002,
        "first_name": "Madonna",
        "last_name": "Ciccone",
        "email": "[email protected]"
    },
    {
        "id": 1000000003,
        "first_name": "Elvis",
        "last_name": "Presley",
        "email": "[email protected]"
    }
]

Need to know

• The maximum memory size for a custom script is 512MB

• The maximum size of a custom script is 4GB

Creating a new script

Follow the steps below:

Step 1 Log into the Patchworks dashboard and select scripts from the left-hand navigation bar.

Step 2 Select the create script button from the scripts page:

Alternatively, you can click the title of an existing script in the upper 'installed' panel, to make changes to a script that you've already added or installed.

Step 3 Add a unique name and a description for your script, then choose your preferred coding language:

Script names must be unique - you can't add two scripts with exactly the same name.

Step 4 Click the create button. The new script is saved and you're now in edit mode, ready to add and test your code:

Adding your code

Follow the steps below:

Step 1 Move down to the code panel.

Step 2 Add your script code (remember that you can use IntelliSense for easy code entry) - for example:

Step 3 When you're ready to test the script, click the save and deploy button:

This saves the code and deploys it to Patchworks, ready for testing/use.

Testing your script

Follow the steps below:

Step 1 Move across to the test panel.

Step 2 Add/paste a payload that can be used to test your script - for example:

Step 3 If your script references variables or flow variables, you can also add variables for testing:

Step 4 Click the run button:

...the script runs against your test payload and results are displayed at the end - for example:

For more detailed information about a script test, you can get logs:

...current logs are displayed:

Step 5 Keep testing the script until you're satisfied that it's working as required.

Any time that you make a change to the script and want to test it, always save and deploy the code first. When you run a script, it always uses the last saved version.

Once these tests are complete, you can:

• Apply a payload-level script to process flows via the script shape

• Apply a field-level custom script to field transformations via the map shape