Skip to content
Postman API Testing Tips

How To Debug In Intellij Using Postman

API Testing Blog

Debugging Your API Tests with IntelliJ and Postman: A Practical Guide

Debugging API tests can be a frustrating experience. You might find yourself staring at a failing test, unable to pinpoint the exact cause of the error. But fear not! This guide will walk you through the process of effectively debugging your API tests using IntelliJ IDEA and Postman, empowering you to resolve issues with confidence.

Setting Up Your Environment

1. Install the necessary tools:

2. Configure your project:

  • Create a new project in IntelliJ: Choose “New Project” and select a suitable project type (e.g., Java, Kotlin, etc.).
  • Add dependencies: If you’re using a framework like RestAssured, add the necessary dependencies to your project’s build file (e.g., pom.xml for Maven projects).
  • Configure Postman: Import your API tests from Postman.

Integrating Postman and IntelliJ for Efficient Debugging

1. Leverage the Power of Breakpoints:

  • Place breakpoints: Within your test code (e.g., in your @Test methods), set breakpoints by clicking in the left margin next to the line of code you want to pause execution at.
  • Trigger debug mode: Run your test from IntelliJ in debug mode (use the “Debug” button).
  • Step through the code: As your code executes, you can step through it line by line using the following control keys in the IntelliJ debugger window:
    • Step Over (F8): Executes the current line of code.
    • Step Into (F7): Steps into the method being called on the current line.
    • Step Out (Shift+F8): Steps out of the current method and returns to the caller.
    • Run to Cursor (Alt+F9): Executes the code until the cursor position.

Example:

import io.restassured.RestAssured;
import org.testng.annotations.Test;


public class UserTest {


    @Test
    public void getUserTest() {
        RestAssured.get("https://api.example.com/users/1")
                .then()
                .statusCode(200); // Set a breakpoint here
    }
}

By placing a breakpoint at the statusCode(200) line and stepping through the code, you can inspect the response object received from the API and verify its status code.

2. Inspect Variables and Evaluate Expressions:

  • The Variables tab: Use the “Variables” tab in the debug window to inspect the values of variables at different points in your code.
  • Evaluate Expressions: Utilize the “Evaluate Expression” feature to evaluate expressions within your code and see their results at runtime.

Troubleshooting with Postman’s Debugging Features

1. Use Postman’s built-in debugger:

  • Enable Debugging: Switch on the “Debugging” toggle in the Postman request tab.
  • Inspect Request and Response: The debugger provides a detailed breakdown of the request and response, including headers, body content, and status codes.
  • Evaluate Variables: The “Variables” tab lets you inspect the values of variables within your script.

2. Utilize Postman’s Test Runner:

  • Run tests in batches: The Postman Test Runner allows you to execute a collection of tests simultaneously.
  • Identify failing tests: It provides a clear snapshot of the results, highlighting any failed tests.

Practical Examples:

1. Handling Unexpected Responses:

In your test code, you are likely asserting the status code, response body, or other aspects of the API response. For instance:

import io.restassured.RestAssured;
import io.restassured.response.Response;
import org.testng.Assert;
import org.testng.annotations.Test;


import static io.restassured.RestAssured.given;


public class UserTest {


    @Test
    public void getUserTest() {
        Response response = given()
                .get("https://api.example.com/users/1");


        Assert.assertEquals(response.statusCode(), 200);


        // Use breakpoints to inspect response body and other assertions
    }
}

If the API returns an unexpected status code (e.g., 404 Not Found), you can place a breakpoint within the assertEquals assertion to inspect the response object and identify the cause of the unexpected result.

2. Examining API Call Parameters:

You might encounter scenarios where the API call is using incorrect parameters. This could be due to issues in your test code or errors in the API implementation itself.

import io.restassured.RestAssured;
import org.testng.annotations.Test;


public class UserTest {


    @Test
    public void createUserTest() {
        RestAssured.given()
                .body("{\"name\":\"John Doe\",\"age\":30}")
                .post("https://api.example.com/users")
                .then()
                .statusCode(201);


        // Set breakpoint to inspect request body and other parameters
    }
}

By setting a breakpoint before the API call, you can inspect the request body and other parameters to ensure they are correct. This will help you identify any discrepancies that may be contributing to the error.

3. Logging Insights for Better Debugging:

Incorporate logging statements within your test code to provide valuable insights into the execution flow and identify potential problems:

import io.restassured.RestAssured;
import org.testng.annotations.Test;


import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


public class UserTest {


    private static final Logger log = LoggerFactory.getLogger(UserTest.class);


    @Test
    public void getUserTest() {
        log.info("Starting getUserTest");


        RestAssured.given()
                .get("https://api.example.com/users/1")
                .then()
                .statusCode(200);


        log.info("Ending getUserTest");
    }
}

By enabling logging in IntelliJ, you can capture debug information that can be particularly helpful in diagnosing issues that might not be easily visible through breakpoints alone.

Conclusion

Debugging API tests using IntelliJ and Postman is a powerful combination that provides a comprehensive set of tools for efficient troubleshooting. By leveraging breakpoints, inspecting variables, and using Postman’s debugging features, you can uncover the root cause of any issues with your tests, ultimately leading to more reliable and successful API testing.

API Testing Blog