Custom Filters

Migration guide

• Migrate to Inline scripting from Custom Filters.
• You can reuse the existing custom filters JavaScript files using Import JS Files.

How to use Custom Filters in Inline Scripts:

• Use the sample code below to import the custom filters JS file in Pre-Request and Post-Request inline scripts.
• The path should be relative (right-click on the file and select Copy Relative Path) to the workspace if you are using Git Sync. Otherwise, use the full path.

const [ filterName ] = require("thunder-tests/custom-filters.js");
 
var result = filterName();
console.log(result);

Custom Filters (Deprecated)

• This feature is deprecated and will be removed in future releases. Please use Import JS Files instead.
• Custom Filters are a way to extend the functionality of Thunder Client by writing custom JavaScript functions.

Create Custom Filters

Create Custom Filters

Step 1

• Create a JavaScript file with custom filters

custom-filters.js

const CryptoJS = require("crypto-js");
const { v4: uuid4 } = require("uuid");
 
async function appendString(input, param1) {
 
     // read a file
    var data = await tc.readFile(input);
    
    // execute a command
    var result = await tc.exec("echo testing");
    
    return `${input} ${data} ${result}`;
}
 
function customHmac(input) {
    console.log("running custom hmac");
    var secretValue = tc.getVar("secret");
 
    let encoded = CryptoJS.HmacSHA256(input, secretValue);
    return encoded.toString(CryptoJS.enc.Base64);
}
 
module.exports = [customHmac, appendString];

Step 2

• Attach custom filter JS files to Collection Settings

Step 3

• Use custom filters in a request

---

Pre-Request Filter

• Run the custom filter directly in the Pre-Run tab as a pre-request script. This is useful for setting env variables.

• This custom filter will not have any arguments and will return no value.

custom-filters.js

function preFilter1() {
 
    console.log("set env variable example");
    let uuid = uuid4();
 
    // ---- save to active environment
    tc.setVar("uuidFromScript", uuid);
 
    // ---- save to local environment
    // tc.setVar("uuidFromScript", uuid, "local");
 
    // ---- save to global environment
    // tc.setVar("uuidFromScript", uuid, "global");
}
 
module.exports = [preFilter1];

---

Post-Request Filter

• Run the custom filter directly in the Tests tab as a post-request script.
• Useful for clean-up tasks after a request or for setting environment variables from the response in advanced use cases.

---

Scripting Reference

• For complete scripting reference, please refer to the Scripting section.