Aexus Answers

Optimize Code: Eliminate Redundant String Literals

Alex Johnson
-
Optimize Code: Eliminate Redundant String Literals

Hey, team! Let's dive into a common code smell and how to fix it. We're talking about those pesky repeated string literals that can make your code a headache to maintain. Specifically, we'll address the issue of a duplicated string literal, /api/sessionActivity/addSessionActivity, appearing multiple times within your test class. This is a crucial step in improving the maintainability and readability of your code. Let's break down why this matters and how to fix it.

The Problem: Repeated String Literals

So, what's the big deal with a string literal showing up more than once? Well, imagine you need to change that path, /api/sessionActivity/addSessionActivity. If it's hardcoded in multiple places, you have to track down every instance and update it. This is not only time-consuming but also a prime opportunity for errors. You might miss an instance, leading to bugs that are tough to track down. Furthermore, it obscures the intent of your code. When you see a string literal scattered throughout, it's not immediately clear what it represents. It makes it harder to understand the code at a glance. The goal is to write code that is easily understandable and easy to modify. This is what we should strive for as developers, right? The repeated use of string literals creates these problems, making the code less clean. Imagine you need to change the base API path in the future. Without a single point of reference, updating every instance manually is tedious and error-prone. What if you need to make changes in the future? Think about the potential for introducing bugs!

This is where a constant comes in. By defining a constant, you give this string a name, making your code more readable. If the string ever needs to change, you only need to update it in one place. This approach simplifies maintenance, reduces errors, and makes your code more resilient to future changes. This is the essence of good coding practice. Having a single source of truth for this kind of thing is critical, so let's get to it.

The Solution: Introduce a Constant

The fix is straightforward: create a static final constant. In Java, this means you're declaring a variable that belongs to the class, is not specific to any instance of the class, and its value cannot be changed once it is initialized. Here's how you would do it, considering the file SessionActivityControllerTest.java:

  1. Identify the Target: Pinpoint the string literal you need to replace: /api/sessionActivity/addSessionActivity.

  2. Declare the Constant: At the top of your class (ideally, right after the class declaration or import statements), add the following line:

    private static final String SESSION_ACTIVITY_PATH = "/api/sessionActivity/addSessionActivity";
    • private: The constant is accessible only within the SessionActivityControllerTest class.
    • static: This means the constant belongs to the class itself, not to any specific instance of the class. It can be accessed via SessionActivityControllerTest.SESSION_ACTIVITY_PATH.
    • final: The value of the constant cannot be changed after initialization.
    • String: The data type of the constant (a string of characters).
    • SESSION_ACTIVITY_PATH: The name of the constant. It should be descriptive, using uppercase letters with underscores to separate words (this is the Java convention for constant names).
    • "/api/sessionActivity/addSessionActivity": The value of the constant, the string literal itself.

  3. Replace Literals: In your test methods, replace all instances of the string literal with the constant:

    // Before
String result = mockMvc.perform(post("/api/sessionActivity/addSessionActivity")

// After
String result = mockMvc.perform(post(SESSION_ACTIVITY_PATH)

    This is a simple find-and-replace operation, but it makes a huge difference to code quality.

  4. Run Tests: After making the changes, make sure all your tests still run without errors. This verifies that the constant has been correctly implemented and hasn't introduced any regressions.

Benefits of Using Constants

Why go through all this trouble? Well, the benefits are pretty clear. Let's recap:

  • Improved Readability: SESSION_ACTIVITY_PATH is much more descriptive than the raw string. It tells you exactly what that string represents, at a glance.
  • Simplified Maintenance: If the API endpoint changes, you update it in one place (the constant declaration) and all instances are automatically updated.
  • Reduced Errors: It's easier to make changes correctly. You don't have to worry about missing an instance of the string literal, which can lead to time-consuming debugging sessions.
  • Code Reusability: If the path is used in other tests or parts of your application, you can simply reuse the constant.
  • Adherence to Best Practices: It shows that you're following established coding conventions, making your code more professional and easier to understand for other developers.

Example Implementation in SessionActivityControllerTest.java

Here is how the SessionActivityControllerTest.java might look after the changes:

package com.example.session_controllers;

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.http.MediaType;
import org.springframework.test.web.servlet.MockMvc;

import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

@SpringBootTest
@AutoConfigureMockMvc
class SessionActivityControllerTest {

    private static final String SESSION_ACTIVITY_PATH = "/api/sessionActivity/addSessionActivity";

    @Autowired
    private MockMvc mockMvc;

    @Test
    void testAddSessionActivity_success() throws Exception {
        String requestBody = "{\"userId\": 1, \"activityType\": \"LOGIN\"}";

        mockMvc.perform(post(SESSION_ACTIVITY_PATH)
                        .contentType(MediaType.APPLICATION_JSON)
                        .content(requestBody))
                .andExpect(status().isOk());
    }

    @Test
    void testAddSessionActivity_invalidJson() throws Exception {
        String requestBody = "invalid json";

        mockMvc.perform(post(SESSION_ACTIVITY_PATH)
                        .contentType(MediaType.APPLICATION_JSON)
                        .content(requestBody))
                .andExpect(status().isBadRequest());
    }
}

In this example, the constant SESSION_ACTIVITY_PATH replaces the duplicated string literal in multiple test methods, making the code much more readable and maintainable. Remember to adjust the code examples to fit the specifics of your test and project structure.

Testing the Changes

After making these changes, it's crucial to run your tests to ensure everything still works as expected. Your acceptance criteria require that the tests run smoothly with the new variable declaration. This is straightforward, and it's a vital step in the development process. Testing provides confidence. Here’s how to do it.

  • Run All Tests: Execute your test suite. In many IDEs (like IntelliJ IDEA or Eclipse), you can right-click on the test class or the test method and select

You may also like