Fix #210: allow forcing quoting for leading/trailing WS

csv/src/main/java/tools/jackson/dataformat/csv/CsvWriteFeature.java

@@ -56,6 +56,20 @@ public enum CsvWriteFeature
      */
     ALWAYS_QUOTE_EMPTY_STRINGS(false),
 
+    /**
+     * Feature that determines whether String values with leading or trailing
+     * whitespace (any character {@code <= 0x0020}, including space and tab)
+     * should be forced to be quoted.
+     * This is useful for interoperability with CSV parsers that trim unquoted
+     * whitespace.
+     *<p>
+     * Default value is {@code false} so that leading/trailing whitespace
+     * does not by itself trigger quoting.
+     *
+     * @since 3.2
+     */
+    QUOTE_STRINGS_WITH_LEADING_TRAILING_WHITESPACE(false),
+
     /**
      * Feature that determines whether values written as Nymbers (from {@code java.lang.Number}
      * valued POJO properties) should be forced to be quoted, regardless of whether they

csv/src/main/java/tools/jackson/dataformat/csv/impl/CsvEncoder.java

@@ -91,33 +91,36 @@ public class CsvEncoder
      */
     protected final int _cfgMinSafeChar;
 
-    protected int _csvFeatures;
+    protected final int _csvFeatures;
 
     /**
      * Marker flag used to determine if to do optimal (aka "strict") quoting
      * checks or not (looser conservative check)
      */
-    protected boolean _cfgOptimalQuoting;
+    protected final boolean _cfgOptimalQuoting;
 
     protected final boolean _cfgAllowsComments;
 
-    protected boolean _cfgIncludeMissingTail;
+    protected final boolean _cfgIncludeMissingTail;
 
-    protected boolean _cfgAlwaysQuoteStrings;
+    protected final boolean _cfgAlwaysQuoteStrings;
 
-    protected boolean _cfgAlwaysQuoteEmptyStrings;
+    protected final boolean _cfgAlwaysQuoteEmptyStrings;
 
     // @since 2.16
-    protected boolean _cfgAlwaysQuoteNumbers;
+    protected final boolean _cfgAlwaysQuoteNumbers;
 
-    protected boolean _cfgEscapeQuoteCharWithEscapeChar;
+    // @since 3.2
+    protected final boolean _cfgQuoteLeadingTrailingWhitespace;
 
-    protected boolean _cfgEscapeControlCharWithEscapeChar;
+    protected final boolean _cfgEscapeQuoteCharWithEscapeChar;
+
+    protected final boolean _cfgEscapeControlCharWithEscapeChar;
 
     /**
      * @since 2.14
      */
-    protected boolean _cfgUseFastDoubleWriter;
+    protected final boolean _cfgUseFastDoubleWriter;
 
     protected final char _cfgQuoteCharEscapeChar;
 
@@ -207,6 +210,7 @@ public CsvEncoder(IOContext ctxt, int csvFeatures, Writer out, CsvSchema schema,
         _cfgAlwaysQuoteStrings = CsvWriteFeature.ALWAYS_QUOTE_STRINGS.enabledIn(csvFeatures);
         _cfgAlwaysQuoteEmptyStrings = CsvWriteFeature.ALWAYS_QUOTE_EMPTY_STRINGS.enabledIn(csvFeatures);
         _cfgAlwaysQuoteNumbers = CsvWriteFeature.ALWAYS_QUOTE_NUMBERS.enabledIn(csvFeatures);
+        _cfgQuoteLeadingTrailingWhitespace = CsvWriteFeature.QUOTE_STRINGS_WITH_LEADING_TRAILING_WHITESPACE.enabledIn(csvFeatures);
         _cfgEscapeQuoteCharWithEscapeChar = CsvWriteFeature.ESCAPE_QUOTE_CHAR_WITH_ESCAPE_CHAR.enabledIn(csvFeatures);
         _cfgEscapeControlCharWithEscapeChar = CsvWriteFeature.ESCAPE_CONTROL_CHARS_WITH_ESCAPE_CHAR.enabledIn(csvFeatures);
 
@@ -259,6 +263,7 @@ public CsvEncoder(CsvEncoder base, CsvSchema newSchema)
         _cfgAlwaysQuoteStrings = base._cfgAlwaysQuoteStrings;
         _cfgAlwaysQuoteEmptyStrings = base._cfgAlwaysQuoteEmptyStrings;
         _cfgAlwaysQuoteNumbers = base._cfgAlwaysQuoteNumbers;
+        _cfgQuoteLeadingTrailingWhitespace = base._cfgQuoteLeadingTrailingWhitespace;
 
         _cfgEscapeQuoteCharWithEscapeChar = base._cfgEscapeQuoteCharWithEscapeChar;
         _cfgEscapeControlCharWithEscapeChar = base._cfgEscapeControlCharWithEscapeChar;
@@ -302,8 +307,7 @@ private void _verifyConfiguration(CsvSchema schema)
             }
         }
     }
-
-
+
     private final char _getQuoteCharEscapeChar(
             final boolean escapeQuoteCharWithEscapeChar,
             final int quoteCharacter,
@@ -342,22 +346,6 @@ public CsvEncoder withSchema(CsvSchema schema) {
         return new CsvEncoder(this, schema);
     }
 
-    /*
-    public CsvEncoder overrideFormatFeatures(int feat) {
-        if (feat != _csvFeatures) {
-            _csvFeatures = feat;
-            _cfgOptimalQuoting = CsvGenerator.Feature.STRICT_CHECK_FOR_QUOTING.enabledIn(feat);
-            _cfgIncludeMissingTail = !CsvGenerator.Feature.OMIT_MISSING_TAIL_COLUMNS.enabledIn(feat);
-            _cfgAlwaysQuoteStrings = CsvGenerator.Feature.ALWAYS_QUOTE_STRINGS.enabledIn(feat);
-            _cfgAlwaysQuoteEmptyStrings = CsvGenerator.Feature.ALWAYS_QUOTE_EMPTY_STRINGS.enabledIn(feat);
-            _cfgAlwaysQuoteNumbers = CsvGenerator.Feature.ALWAYS_QUOTE_NUMBERS.enabledIn(feat);
-            _cfgEscapeQuoteCharWithEscapeChar = CsvGenerator.Feature.ESCAPE_QUOTE_CHAR_WITH_ESCAPE_CHAR.enabledIn(feat);
-            _cfgEscapeControlCharWithEscapeChar = Feature.ESCAPE_CONTROL_CHARS_WITH_ESCAPE_CHAR.enabledIn(feat);
-        }
-        return this;
-    }
-    */
-
     public CsvEncoder setOutputEscapes(int[] esc) {
         _outputEscapes = (esc != null) ? esc : sOutputEscapes;
         return this;
@@ -1156,6 +1144,14 @@ protected boolean _mayNeedQuotes(String value, int length, int columnIndex)
         if (_cfgQuoteCharacter < 0) {
             return false;
         }
+        // [dataformats-text#210]: check for leading/trailing whitespace
+        if (_cfgQuoteLeadingTrailingWhitespace && length > 0) {
+            char first = value.charAt(0);
+            char last = value.charAt(length - 1);
+            if (first <= ' ' || last <= ' ') {
+                return true;
+            }
+        }
         // may skip checks unless we want exact checking
         if (_cfgOptimalQuoting) {
             // 31-Dec-2014, tatu: Comment lines start with # so quote if starts with #

csv/src/test/java/tools/jackson/dataformat/csv/ser/QuoteLeadingTrailingWhitespace210Test.java

@@ -0,0 +1,84 @@
+package tools.jackson.dataformat.csv.ser;
+
+import org.junit.jupiter.api.Test;
+
+import tools.jackson.dataformat.csv.*;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+// [dataformats-text#210]: Quote strings with leading/trailing whitespace
+public class QuoteLeadingTrailingWhitespace210Test extends ModuleTestBase
+{
+    private final CsvMapper MAPPER = mapperForCsv();
+
+    @Test
+    public void testLeadingSpaceQuoted() throws Exception
+    {
+        final CsvSchema schema = MAPPER.schemaFor(IdDesc.class)
+                .withLineSeparator("\n");
+        String csv = MAPPER.writer(schema)
+                .with(CsvWriteFeature.QUOTE_STRINGS_WITH_LEADING_TRAILING_WHITESPACE)
+                .writeValueAsString(new IdDesc(" hello", "world"));
+        assertEquals("\" hello\",world\n", csv);
+    }
+
+    @Test
+    public void testTrailingSpaceQuoted() throws Exception
+    {
+        final CsvSchema schema = MAPPER.schemaFor(IdDesc.class)
+                .withLineSeparator("\n");
+        String csv = MAPPER.writer(schema)
+                .with(CsvWriteFeature.QUOTE_STRINGS_WITH_LEADING_TRAILING_WHITESPACE)
+                .writeValueAsString(new IdDesc("hello", "world "));
+        assertEquals("hello,\"world \"\n", csv);
+    }
+
+    @Test
+    public void testBothLeadingAndTrailingSpaceQuoted() throws Exception
+    {
+        final CsvSchema schema = MAPPER.schemaFor(IdDesc.class)
+                .withLineSeparator("\n");
+        String csv = MAPPER.writer(schema)
+                .with(CsvWriteFeature.QUOTE_STRINGS_WITH_LEADING_TRAILING_WHITESPACE)
+                .writeValueAsString(new IdDesc(" both ", " ends "));
+        assertEquals("\" both \",\" ends \"\n", csv);
+    }
+
+    @Test
+    public void testTabCountsAsWhitespace() throws Exception
+    {
+        final CsvSchema schema = MAPPER.schemaFor(IdDesc.class)
+                .withLineSeparator("\n");
+        String csv = MAPPER.writer(schema)
+                .with(CsvWriteFeature.QUOTE_STRINGS_WITH_LEADING_TRAILING_WHITESPACE)
+                .writeValueAsString(new IdDesc("\thello", "world"));
+        assertEquals("\"\thello\",world\n", csv);
+    }
+
+    @Test
+    public void testNoQuotingWithoutFeature() throws Exception
+    {
+        final CsvSchema schema = MAPPER.schemaFor(IdDesc.class)
+                .withLineSeparator("\n");
+        // With strict quoting (optimal), leading spaces should NOT trigger quoting
+        // unless the new feature is enabled
+        String csv = MAPPER.writer(schema)
+                .with(CsvWriteFeature.STRICT_CHECK_FOR_QUOTING)
+                .without(CsvWriteFeature.QUOTE_STRINGS_WITH_LEADING_TRAILING_WHITESPACE)
+                .writeValueAsString(new IdDesc(" hello", "world "));
+        assertEquals(" hello,world \n", csv);
+    }
+
+    @Test
+    public void testNoWhitespaceNoQuoting() throws Exception
+    {
+        final CsvSchema schema = MAPPER.schemaFor(IdDesc.class)
+                .withLineSeparator("\n");
+        // Strings without leading/trailing whitespace should not be affected
+        String csv = MAPPER.writer(schema)
+                .with(CsvWriteFeature.QUOTE_STRINGS_WITH_LEADING_TRAILING_WHITESPACE)
+                .with(CsvWriteFeature.STRICT_CHECK_FOR_QUOTING)
+                .writeValueAsString(new IdDesc("hello", "world"));
+        assertEquals("hello,world\n", csv);
+    }
+}

release-notes/VERSION

@@ -30,6 +30,10 @@ implementations)
 #109: (yaml) `YAMLMapper` doesn't close output file if an error occurs
  (reported by Martin W)
  (fix by @cowtowncoder, w/ Claude code)
+#210: (csv) Quote strings with leading/trailing spaces in csv
+  (`CsvWriteFeature.QUOTE_STRINGS_WITH_LEADING_TRAILING_WHITESPACE`)
+ (requested by @sfzhi)
+ (implemented by @cowtowncoder, w/ Claude code)
 #214: (yaml) Expose custom tags via `YAMLParser.getRawTag()`
  (requested by Alexander T)
  (fix by @cowtowncoder, w/ Claude code)