CSV-203: withNullString value is printed without quotes when QuoteMode.ALL is specified

Author: kai

src/main/java/org/apache/commons/csv/CSVFormat.java

@@ -946,7 +946,16 @@ public void print(final Object value, final Appendable out, final boolean newRec
         // Only call CharSequence.toString() if you have to, helps GC-free use cases.
         CharSequence charSequence;
         if (value == null) {
-            charSequence = nullString == null ? Constants.EMPTY : nullString;
+            // https://issues.apache.org/jira/browse/CSV-203
+            if (null == nullString) {
+                charSequence = Constants.EMPTY;
+            } else {
+                if (QuoteMode.ALL == quoteMode) {
+                    charSequence = quoteCharacter + nullString + quoteCharacter;
+                } else {
+                    charSequence = nullString;
+                }
+            }
         } else {
             charSequence = value instanceof CharSequence ? (CharSequence) value : value.toString();
         }

src/test/java/org/apache/commons/csv/issues/JiraCsv203Test.java

@@ -0,0 +1,68 @@
+package org.apache.commons.csv.issues;
+
+import org.apache.commons.csv.CSVFormat;
+import org.apache.commons.csv.CSVPrinter;
+import org.apache.commons.csv.QuoteMode;
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * JIRA: <a href="https://issues.apache.org/jira/browse/CSV-203">withNullString value is printed without quotes when QuoteMode.ALL is specified</a>
+ */
+public class JiraCsv203Test {
+
+    @Test
+    public void testQuoteModeAll() throws Exception {
+        CSVFormat format = CSVFormat.EXCEL
+                .withNullString("N/A")
+                .withIgnoreSurroundingSpaces(true)
+                .withQuoteMode(QuoteMode.ALL);
+
+        StringBuffer buffer = new StringBuffer();
+        CSVPrinter printer = new CSVPrinter(buffer, format);
+        printer.printRecord(new Object[] { null, "Hello", null, "World" });
+
+        Assert.assertEquals("\"N/A\",\"Hello\",\"N/A\",\"World\"\r\n", buffer.toString());
+    }
+
+    @Test
+    public void testWithoutQuoteMode() throws Exception {
+        CSVFormat format = CSVFormat.EXCEL
+                .withNullString("N/A")
+                .withIgnoreSurroundingSpaces(true);
+
+        StringBuffer buffer = new StringBuffer();
+        CSVPrinter printer = new CSVPrinter(buffer, format);
+        printer.printRecord(new Object[] { null, "Hello", null, "World" });
+
+        Assert.assertEquals("N/A,Hello,N/A,World\r\n", buffer.toString());
+    }
+
+    @Test
+    public void testQuoteModeMinimal() throws Exception {
+        CSVFormat format = CSVFormat.EXCEL
+                .withNullString("N/A")
+                .withIgnoreSurroundingSpaces(true)
+                .withQuoteMode(QuoteMode.MINIMAL);
+
+        StringBuffer buffer = new StringBuffer();
+        CSVPrinter printer = new CSVPrinter(buffer, format);
+        printer.printRecord(new Object[] { null, "Hello", null, "World" });
+
+        Assert.assertEquals("N/A,Hello,N/A,World\r\n", buffer.toString());
+    }
+
+    @Test
+    public void testQuoteModeNoneNumeric() throws Exception {
+        CSVFormat format = CSVFormat.EXCEL
+                .withNullString("N/A")
+                .withIgnoreSurroundingSpaces(true)
+                .withQuoteMode(QuoteMode.NON_NUMERIC);
+
+        StringBuffer buffer = new StringBuffer();
+        CSVPrinter printer = new CSVPrinter(buffer, format);
+        printer.printRecord(new Object[] { null, "Hello", null, "World" });
+
+        Assert.assertEquals("N/A,\"Hello\",N/A,\"World\"\r\n", buffer.toString());
+    }
+}