Add unit tests for CsvTableFormatter FINAL

src/test/java/com/group5/csv/io/CsvTableFormatterTest.java

@@ -0,0 +1,115 @@
+package com.group5.csv.io;
+
+import com.group5.csv.core.Row;
+import com.group5.csv.testutils.VirtualReader;
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * Test class for CsvTableFormatter
+ */
+class CsvTableFormatterTest {
+
+    /**
+     * Helper to read all rows from a CsvReader.
+     */
+    private List<Row> readAll(CsvReader reader) throws Exception {
+        List<Row> rows = new ArrayList<>();
+        Row row;
+        while ((row = reader.readRow()) != null) {
+            rows.add(row);
+        }
+        return rows;
+    }
+
+    @Test
+    void formatTable_withHeadersAndRows_producesBorderedTable() throws Exception {
+        String csv = """
+                name,age,city
+                Alice,30,Dublin
+                Bob,25,Cork
+                """;
+
+        CsvConfig config = CsvConfig.builder()
+                .setHasHeader(true)
+                .build();
+
+        String table;
+        try (CsvReader reader = new CsvReader(new VirtualReader(csv), config)) {
+            List<Row> rows = readAll(reader);
+
+            // Use the reader-based constructor so formatter picks up the same newline
+            CsvTableFormatter formatter = new CsvTableFormatter(reader);
+
+            table = formatter.formatTable(rows);
+        }
+
+        assertNotNull(table);
+        assertFalse(table.isEmpty(), "Table output should not be empty");
+
+        // Basic structure checks
+        assertTrue(table.startsWith("+"), "Table should start with a separator line");
+        assertTrue(table.trim().endsWith("+"), "Table should end with a separator line");
+        assertTrue(table.contains("|"), "Table should use '|' as column borders");
+
+        // Headers present
+        assertTrue(table.contains("name"), "Header 'name' should be present");
+        assertTrue(table.contains("age"), "Header 'age' should be present");
+        assertTrue(table.contains("city"), "Header 'city' should be present");
+
+        // Data present
+        assertTrue(table.contains("Alice"), "Data row should contain 'Alice'");
+        assertTrue(table.contains("Bob"), "Data row should contain 'Bob'");
+    }
+
+    @Test
+    void formatTable_emptyList_returnsEmptyString() {
+        CsvTableFormatter formatter = new CsvTableFormatter("\n");
+        String table = formatter.formatTable(List.of());
+
+        assertNotNull(table);
+        assertEquals("", table, "Empty input should produce an empty string");
+    }
+
+    @Test
+    void formatRow_multilineCell_producesMultipleLinesWithBorders() throws Exception {
+        String csv = """
+            name,comment
+            Alice,"Hello
+            World"
+            """;
+
+        CsvConfig config = CsvConfig.builder()
+                .setHasHeader(true)
+                .build();
+
+        String formatted;
+        try (CsvReader reader = new CsvReader(new VirtualReader(csv), config)) {
+            // Directly read all data rows (header is handled inside CsvReader)
+            List<Row> rows = readAll(reader);
+            assertEquals(1, rows.size(), "Expected one data row");
+
+            CsvTableFormatter formatter = new CsvTableFormatter(reader);
+            formatted = formatter.formatRow(rows.get(0));
+        }
+
+        assertNotNull(formatted);
+
+        // It should contain both lines of the multi-line cell
+        assertTrue(formatted.contains("Hello"), "First line of cell should appear");
+        assertTrue(formatted.contains("World"), "Second line of cell should appear");
+
+        // Split on line breaks and check borders
+        String[] lines = formatted.split("\\R");
+        assertTrue(lines.length >= 2, "Multiline cell should produce multiple lines");
+
+        for (String line : lines) {
+            assertTrue(line.startsWith("|"), "Each formatted line should start with '|'");
+            assertTrue(line.endsWith("|"), "Each formatted line should end with '|'");
+        }
+    }
+}