This commit is related to the article BAEL-7017 (#14985)

This commit aims to add a new test class named "WriteHashmaptoCVSFileUnitTest.java" that explains how to write HashMap to a CSV file.

core-java-modules/core-java-collections-maps-7/src/test/java/com/baeldung/map/writehashmaptocsvfile/WriteHashmaptoCVSFileUnitTest.java

@@ -0,0 +1,62 @@
+package com.baeldung.writehashmaptocsvfile;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class WriteHashmaptoCVSFileUnitTest {
+
+    @Test
+    public void givenEmployeeData_whenWriteToCSV_thenCSVFileIsCreated() {
+        Map<String, String> employeeData = new HashMap<>();
+        employeeData.put("Name", "John Doe");
+        employeeData.put("Title", "Software Engineer");
+        employeeData.put("Department", "Engineering");
+        employeeData.put("Salary", "75000");
+        try (FileWriter csvWriter = new FileWriter("employee_data.csv")) {
+            // Write header row
+            csvWriter.append("Name,Title,Department,Salary\n");
+
+            // Write data row
+            csvWriter.append(employeeData.get("Name")).append(",");
+            csvWriter.append(employeeData.get("Title")).append(",");
+            csvWriter.append(employeeData.get("Department")).append(",");
+            csvWriter.append(employeeData.get("Salary")).append("\n");
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+        // Ensure the CSV file exists
+        assertTrue(new File("employee_data.csv").exists(), "CSV file does not exist!");
+
+    }
+
+    @Test
+    public void givenCSVFile_whenRead_thenContentsMatchExpected() {
+        // Read the actual content of the CSV file
+        StringBuilder actualCsvContent = new StringBuilder();
+        try {
+            Files.lines(Paths.get("employee_data.csv"))
+                    .forEach(line -> actualCsvContent.append(line).append("\n"));
+
+            // Define the expected CSV content
+            String expectedCsvContent = "Name,Title,Department,Salary\n" +
+                    "John Doe,Software Engineer,Engineering,75000\n";
+
+            // Compare the actual content with the expected content
+            assertEquals(expectedCsvContent, actualCsvContent.toString());
+
+            System.out.println("CSV file created successfully.");
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}