Enforcing Region Rules Before Sending API Requests

When testing APIs that involve addresses, it’s easy to focus only on fields like street or zipCode—but state-level rules matter too. Some states may be unsupported, restricted, or require underwriting.

In my API testing setup, I wanted to ensure only valid U.S. states were used in test data—especially for policies limited to domestic clients. Here’s how I enforce controlled randomness in Postman, using a clean whitelist approach and dynamic state selection.

Goal

Ensure that any test-generated address always uses a valid U.S. state (and potentially simulate region-based rules).

Building the Script

1. Define an array of accepted U.S. states

const insuredStates = [
  'AL', 'AK', 'AZ', 'AR', 'CA', 'CO', 'CT', 'DE', 'FL', 'GA',
  'HI', 'ID', 'IL', 'IN', 'IA', 'KS', 'KY', 'LA', 'ME', 'MD',
  'MA', 'MI', 'MN', 'MS', 'MO', 'MT', 'NE', 'NV', 'NH', 'NJ',
  'NM', 'NY', 'NC', 'ND', 'OH', 'OK', 'OR', 'PA', 'RI', 'SC',
  'SD', 'TN', 'TX', 'UT', 'VT', 'VA', 'WA', 'WV', 'WI', 'WY', 'DC'
];
pm.collectionVariables.set('insuredStates', insuredStates);

2. Randomly pick one of the states

function generateRandomState() {
  let randomInsuredState = Math.floor(Math.random() * insuredStates.length);
  return insuredStates[randomInsuredState];
}

3. Use it in your address object

const clientAddress = {
  street: generateRandomStreetAddress(),
  city: generateRandomCity(),
  state: generateRandomState(),
  zipCode: generateRandomZipCode(),
  country: "US"
};
pm.collectionVariables.set("clientAddress", JSON.stringify(clientAddress));

Why This Matters

• Test accuracy: Ensures you're only testing quote logic for regions that are eligible.

• Prevents false positives: Invalid states could trigger eligibility failures, muddying test results.

• Real-world reflection: Many systems restrict coverages by geography—your tests should too.

Tip: Vary State Logic by Role

Want to simulate restricted regions for certain scenarios (e.g., a specific state requires extra validation)? You can inject conditional logic in form of a post-request script like this:

if (state === "NY") {
  pm.expect.fail("New York requires manual review for freelance policies.");
}

Takeaways

Controlled randomness is powerful. By using a valid state list, you:

• Keep your test data clean

• Reflect business rules early in the flow

• Prevent downstream noise caused by bad inputs