Added unit tests for multilineWrap

Author: janvanmansum

src/test/java/edu/harvard/iq/dataverse/util/bagit/BagGeneratorMultilineWrapTest.java

@@ -0,0 +1,102 @@
+package edu.harvard.iq.dataverse.util.bagit;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Tests adapted for DD-2093: verify the behavior of BagGenerator.multilineWrap.
+ */
+public class BagGeneratorMultilineWrapTest {
+
+    private static Method multilineWrap;
+
+    @BeforeAll
+    static void setUp() throws NoSuchMethodException {
+        // Access the private static method via reflection
+        multilineWrap = BagGenerator.class.getDeclaredMethod("multilineWrap", String.class);
+        multilineWrap.setAccessible(true);
+    }
+
+    private String callMultilineWrap(String input) {
+        try {
+            return (String) multilineWrap.invoke(null, input);
+        } catch (IllegalAccessException | InvocationTargetException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    @Test
+    void shortLine_noWrap() {
+        String input = "Hello world";
+        String out = callMultilineWrap(input);
+        assertThat(out).isEqualTo("Hello world");
+    }
+
+    @Test
+    void exactBoundary_78chars_noWrap() {
+        String input = repeat('a', 78);
+        String out = callMultilineWrap(input);
+        assertThat(out).isEqualTo(input);
+    }
+
+    @Test
+    void longSingleWord_wrapsAt78WithIndent() {
+        String input = repeat('a', 100);
+        String expected = repeat('a', 78) + "\r\n " + repeat('a', 22);
+        String out = callMultilineWrap(input);
+        assertThat(out).isEqualTo(expected);
+    }
+
+    @Test
+    void multiline_input_indentsSecondAndSubsequentOriginalLines() {
+        String input = "Line1\nLine2";
+        String expected = "Line1\r\n Line2";
+        String out = callMultilineWrap(input);
+        assertThat(out).isEqualTo(expected);
+    }
+
+    @Test
+    void multiline_withCRLF_normalizedAndIndented() {
+        String input = "First line\r\nSecond line";
+        String expected = "First line\r\n Second line";
+        String out = callMultilineWrap(input);
+        assertThat(out).isEqualTo(expected);
+    }
+
+    @Test
+    void emptyLines_trimmedAndSkipped() {
+        String input = "Line1\n\nLine3";
+        String expected = "Line1\r\n Line3";
+        String out = callMultilineWrap(input);
+        assertThat(out).isEqualTo(expected);
+    }
+
+    @Test
+    void whitespaceOnlyLines_ignored() {
+        String input = "Line1\n   \n\t\t\nLine3";
+        String expected = "Line1\r\n Line3";
+        String out = callMultilineWrap(input);
+        assertThat(out).isEqualTo(expected);
+    }
+
+    @Test
+    void longSecondLine_preservesIndentOnWraps() {
+        String line1 = "Header";
+        String line2 = repeat('b', 90);
+        String input = line1 + "\n" + line2;
+        String expected = "Header\r\n " + repeat('b', 78) + "\r\n " + repeat('b', 12);
+        String out = callMultilineWrap(input);
+        assertThat(out).isEqualTo(expected);
+    }
+
+    private static String repeat(char c, int n) {
+        StringBuilder sb = new StringBuilder(n);
+        for (int i = 0; i < n; i++) sb.append(c);
+        return sb.toString();
+    }
+}