Added some tests for CsvPrinter.java

core/src/main/java/de/jplag/reporting/csv/CsvPrinter.java

@@ -1,7 +1,9 @@
 package de.jplag.reporting.csv;
 
+import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.IOException;
+import java.io.OutputStreamWriter;
 import java.io.Writer;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -79,11 +81,29 @@ public void setLineEnd(String lineEnd) {
      */
     public void printToFile(File file) throws IOException {
         try (Writer writer = FileUtils.openFileWriter(file)) {
-            this.writeTitleRow(writer);
+            this.printCsv(writer);
+        }
+    }
+
+    public String printToString() throws IOException {
+        String csv;
 
-            for (String[] datum : this.data) {
-                this.printRow(writer, datum);
+        try (ByteArrayOutputStream outputStream = new ByteArrayOutputStream()) {
+            try (Writer writer = new OutputStreamWriter(outputStream)) {
+                this.printCsv(writer);
             }
+
+            csv = outputStream.toString();
+        }
+
+        return csv;
+    }
+
+    private void printCsv(Writer writer) throws IOException {
+        this.writeTitleRow(writer);
+
+        for (String[] datum : this.data) {
+            this.printRow(writer, datum);
         }
     }
 

core/src/test/java/de/jplag/reporting/csv/CsvPrinterTest.java

@@ -0,0 +1,35 @@
+package de.jplag.reporting.csv;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+public class CsvPrinterTest {
+    private static final String EXPECTED_CSV_TEXT = "1,test1\r\n2,\"test2,\"\"x\"\"\"\r\n";
+    private static final List<CsvTestItem> TEST_ITEMS = List.of(new CsvTestItem(1, "test1"), new CsvTestItem(2, "test2,\"x\""));
+
+    @Test
+    void testPrintWithReflectiveMapper() throws IOException {
+        CsvDataMapper<CsvTestItem> mapper = new ReflectiveCsvDataMapper<>(CsvTestItem.class);
+        CsvPrinter<CsvTestItem> printer = new CsvPrinter<>(mapper);
+
+        printer.addRows(TEST_ITEMS);
+
+        Assertions.assertEquals(EXPECTED_CSV_TEXT, printer.printToString());
+    }
+
+    @Test
+    void testPrintWithHardcodedMapper() throws IOException {
+        CsvDataMapper<CsvTestItem> mapper = new HardcodedCsvDataMapper<>(2, item -> new Object[] {item.number(), item.text()});
+        CsvPrinter<CsvTestItem> printer = new CsvPrinter<>(mapper);
+
+        printer.addRows(TEST_ITEMS);
+
+        Assertions.assertEquals(EXPECTED_CSV_TEXT, printer.printToString());
+    }
+
+    private record CsvTestItem(@CsvValue(1) int number, @CsvValue(2) String text) {
+    }
+}