NIFI-8761 Enable not setting a value for Escape Character in CSVReade… (#5249)

NIFI-8761 Enable not setting a value for Escape Character in CSVReader controller service

Co-authored-by: Pierre Villard <pierre.villard.fr@gmail.com>

nifi-nar-bundles/nifi-extension-utils/nifi-record-utils/nifi-standard-record-utils/src/main/java/org/apache/nifi/csv/CSVUtils.java

@@ -67,7 +67,7 @@ public class CSVUtils {
         .name("Quote Character")
         .description("The character that is used to quote values so that escape characters do not have to be used. If the property has been specified via Expression Language " +
                 "but the expression gets evaluated to an invalid Quote Character at runtime, then it will be skipped and the default Quote Character will be used.")
-        .addValidator(new CSVValidators.SingleCharacterValidator())
+        .addValidator(CSVValidators.SINGLE_CHAR_VALIDATOR)
         .expressionLanguageSupported(ExpressionLanguageScope.FLOWFILE_ATTRIBUTES)
         .dependsOn(CSV_FORMAT, CUSTOM)
         .defaultValue("\"")
@@ -101,7 +101,7 @@ public class CSVUtils {
     public static final PropertyDescriptor COMMENT_MARKER = new PropertyDescriptor.Builder()
         .name("Comment Marker")
         .description("The character that is used to denote the start of a comment. Any line that begins with this comment will be ignored.")
-        .addValidator(new CSVValidators.SingleCharacterValidator())
+        .addValidator(CSVValidators.SINGLE_CHAR_VALIDATOR)
         .expressionLanguageSupported(ExpressionLanguageScope.FLOWFILE_ATTRIBUTES)
         .dependsOn(CSV_FORMAT, CUSTOM)
         .required(false)
@@ -109,8 +109,9 @@ public class CSVUtils {
     public static final PropertyDescriptor ESCAPE_CHAR = new PropertyDescriptor.Builder()
         .name("Escape Character")
         .description("The character that is used to escape characters that would otherwise have a specific meaning to the CSV Parser. If the property has been specified via Expression Language " +
-                "but the expression gets evaluated to an invalid Escape Character at runtime, then it will be skipped and the default Escape Character will be used.")
-        .addValidator(new CSVValidators.SingleCharacterValidator())
+                "but the expression gets evaluated to an invalid Escape Character at runtime, then it will be skipped and the default Escape Character will be used. " +
+                "Setting it to an empty string means no escape character should be used.")
+        .addValidator(CSVValidators.EMPTY_OR_SINGLE_CHAR_VALIDATOR)
         .expressionLanguageSupported(ExpressionLanguageScope.FLOWFILE_ATTRIBUTES)
         .dependsOn(CSV_FORMAT, CUSTOM)
         .defaultValue("\\")
@@ -284,7 +285,7 @@ public class CSVUtils {
         final Character quoteChar = getCharUnescaped(context, QUOTE_CHAR, variables);
         format = format.withQuote(quoteChar);
 
-        final Character escapeChar = getCharUnescaped(context, ESCAPE_CHAR, variables);
+        final Character escapeChar = context.getProperty(CSVUtils.ESCAPE_CHAR).evaluateAttributeExpressions(variables).getValue().isEmpty() ? null : getCharUnescaped(context, ESCAPE_CHAR, variables);
         format = format.withEscape(escapeChar);
 
         format = format.withTrim(context.getProperty(TRIM_FIELDS).asBoolean());

nifi-nar-bundles/nifi-extension-utils/nifi-record-utils/nifi-standard-record-utils/src/main/java/org/apache/nifi/csv/CSVValidators.java

@@ -25,57 +25,17 @@ import java.util.HashSet;
 import java.util.Set;
 
 public class CSVValidators {
+    private static final Set<String> illegalChars = new HashSet<>();
 
-    public static class SingleCharacterValidator implements Validator {
-        private static final Set<String> illegalChars = new HashSet<>();
-
-        static {
-            illegalChars.add("\r");
-            illegalChars.add("\n");
-        }
-
-        @Override
-        public ValidationResult validate(final String subject, final String input, final ValidationContext context) {
-
-            if (input == null) {
-                return new ValidationResult.Builder()
-                        .input(input)
-                        .subject(subject)
-                        .valid(false)
-                        .explanation("Input is null for this property")
-                        .build();
-            }
-
-            if (!context.isExpressionLanguageSupported(subject) || !context.isExpressionLanguagePresent(input)) {
-                final String unescaped = CSVUtils.unescape(input);
-                if (unescaped.length() != 1) {
-                    return new ValidationResult.Builder()
-                            .input(input)
-                            .subject(subject)
-                            .valid(false)
-                            .explanation("Value must be exactly 1 character but was " + input.length() + " in length")
-                            .build();
-                }
-
-                if (illegalChars.contains(unescaped)) {
-                    return new ValidationResult.Builder()
-                            .input(input)
-                            .subject(subject)
-                            .valid(false)
-                            .explanation(input + " is not a valid character for this property")
-                            .build();
-                }
-            }
-
-            return new ValidationResult.Builder()
-                    .input(input)
-                    .subject(subject)
-                    .valid(true)
-                    .build();
-        }
-
+    static {
+        illegalChars.add("\r");
+        illegalChars.add("\n");
     }
 
+    public static final Validator SINGLE_CHAR_VALIDATOR = createSingleCharValidator(false);
+
+    public static final Validator EMPTY_OR_SINGLE_CHAR_VALIDATOR = createSingleCharValidator(true);
+
     public static final Validator UNESCAPED_SINGLE_CHAR_VALIDATOR = new Validator() {
         @Override
         public ValidationResult validate(final String subject, final String input, final ValidationContext context) {
@@ -101,4 +61,57 @@ public class CSVValidators {
         }
     };
 
+    private static Validator createSingleCharValidator(final boolean canBeEmpty) {
+        return new Validator() {
+            @Override
+            public ValidationResult validate(String subject, String input, ValidationContext context) {
+                if (input == null) {
+                    return new ValidationResult.Builder()
+                            .input(input)
+                            .subject(subject)
+                            .valid(false)
+                            .explanation("Input is null for this property")
+                            .build();
+                }
+
+                if (input.isEmpty()) {
+                    return new ValidationResult.Builder()
+                            .input(input)
+                            .subject(subject)
+                            .valid(canBeEmpty)
+                            .explanation("Value must be exactly 1 character but was 0 in length")
+                            .build();
+                }
+
+
+                if (!context.isExpressionLanguageSupported(subject) || !context.isExpressionLanguagePresent(input)) {
+                    final String unescaped = CSVUtils.unescape(input);
+                    if (unescaped.length() != 1) {
+                        return new ValidationResult.Builder()
+                                .input(input)
+                                .subject(subject)
+                                .valid(false)
+                                .explanation("Value must be exactly 1 character but was " + input.length() + " in length")
+                                .build();
+                    }
+
+                    if (illegalChars.contains(unescaped)) {
+                        return new ValidationResult.Builder()
+                                .input(input)
+                                .subject(subject)
+                                .valid(false)
+                                .explanation(input + " is not a valid character for this property")
+                                .build();
+                    }
+                }
+
+                return new ValidationResult.Builder()
+                        .input(input)
+                        .subject(subject)
+                        .valid(true)
+                        .build();
+            }
+        };
+    }
+
 }

nifi-nar-bundles/nifi-extension-utils/nifi-record-utils/nifi-standard-record-utils/src/test/java/org/apache/nifi/csv/CSVUtilsTest.java

@@ -119,7 +119,7 @@ public class CSVUtilsTest {
 
         assertEquals(',', csvFormat.getDelimiter());
         assertEquals('"', (char) csvFormat.getQuoteCharacter());
-        assertEquals('\\', (char) csvFormat.getEscapeCharacter());
+        assertNull(csvFormat.getEscapeCharacter());
         assertNull(csvFormat.getCommentMarker());
     }
 

nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/pom.xml

@@ -146,7 +146,8 @@
                         <exclude>src/test/resources/csv/extra-white-space.csv</exclude>
                         <exclude>src/test/resources/csv/multi-bank-account.csv</exclude>
                         <exclude>src/test/resources/csv/single-bank-account.csv</exclude>
-                        <exclude>src/test/resources/csv/multi-bank-account_escapedchar.csv</exclude>
+                        <exclude>src/test/resources/csv/multi-bank-account_escapechar.csv</exclude>
+                        <exclude>src/test/resources/csv/multi-bank-account_spec_delimiter.csv</exclude>
                         <exclude>src/test/resources/csv/prov-events.csv</exclude>
                         <exclude>src/test/resources/grok/error-with-stack-trace.log</exclude>
                         <exclude>src/test/resources/grok/nifi-log-sample-multiline-with-stacktrace.log</exclude>

nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/test/java/org/apache/nifi/csv/TestCSVRecordReader.java

@@ -620,7 +620,7 @@ public class TestCSVRecordReader {
     }
 
     @Test
-    public void testMultipleRecordsEscapedWithSpecialChar() throws IOException, MalformedRecordException {
+    public void testMultipleRecordsDelimitedWithSpecialChar() throws IOException, MalformedRecordException {
 
         char delimiter = StringEscapeUtils.unescapeJava("\u0001").charAt(0);
 
@@ -630,7 +630,7 @@ public class TestCSVRecordReader {
 
         final RecordSchema schema = new SimpleRecordSchema(fields);
 
-        try (final InputStream fis = new FileInputStream("src/test/resources/csv/multi-bank-account_escapedchar.csv");
+        try (final InputStream fis = new FileInputStream("src/test/resources/csv/multi-bank-account_spec_delimiter.csv");
             final CSVRecordReader reader = createReader(fis, schema, format)) {
 
             final Object[] firstRecord = reader.nextRecord().getValues();
@@ -645,6 +645,46 @@ public class TestCSVRecordReader {
         }
     }
 
+    @Test
+    public void testMultipleRecordsEscapedWithChar() throws IOException {
+
+        final CSVFormat format = CSVFormat.DEFAULT.withFirstRecordAsHeader().withTrim().withQuote('"').withDelimiter(",".charAt(0)).withEscape("\\".charAt(0));
+        final List<RecordField> fields = getDefaultFields();
+        fields.replaceAll(f -> f.getFieldName().equals("balance") ? new RecordField("balance", doubleDataType) : f);
+
+        final RecordSchema schema = new SimpleRecordSchema(fields);
+
+        try (final InputStream fis = new FileInputStream("src/test/resources/csv/multi-bank-account_escapechar.csv");
+             final CSVRecordReader reader = createReader(fis, schema, format)) {
+
+            assertThrows(MalformedRecordException.class, () -> reader.nextRecord());
+        }
+    }
+
+    @Test
+    public void testMultipleRecordsEscapedWithNull() throws IOException, MalformedRecordException {
+
+        final CSVFormat format = CSVFormat.DEFAULT.withFirstRecordAsHeader().withTrim().withQuote('"').withDelimiter(",".charAt(0)).withEscape(null);
+        final List<RecordField> fields = getDefaultFields();
+        fields.replaceAll(f -> f.getFieldName().equals("balance") ? new RecordField("balance", doubleDataType) : f);
+
+        final RecordSchema schema = new SimpleRecordSchema(fields);
+
+        try (final InputStream fis = new FileInputStream("src/test/resources/csv/multi-bank-account_escapechar.csv");
+             final CSVRecordReader reader = createReader(fis, schema, format)) {
+
+            final Object[] firstRecord = reader.nextRecord().getValues();
+            final Object[] firstExpectedValues = new Object[] {"1", "John Doe\\", 4750.89D, "123 My Street", "My City", "MS", "11111", "USA"};
+            Assert.assertArrayEquals(firstExpectedValues, firstRecord);
+
+            final Object[] secondRecord = reader.nextRecord().getValues();
+            final Object[] secondExpectedValues = new Object[] {"2", "Jane Doe", 4820.09D, "321 Your Street", "Your City", "NY", "33333", "USA"};
+            Assert.assertArrayEquals(secondExpectedValues, secondRecord);
+
+            assertNull(reader.nextRecord());
+        }
+    }
+
     @Test
     public void testQuote() throws IOException, MalformedRecordException {
         final CSVFormat format = CSVFormat.RFC4180.withFirstRecordAsHeader().withTrim().withQuote('"');

nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/test/java/org/apache/nifi/csv/TestCSVValidators.java

@@ -33,16 +33,25 @@ public class TestCSVValidators {
     /*** SingleCharValidator **/
     @Test
     public void testSingleCharNullValue() {
-        CSVValidators.SingleCharacterValidator validator = new CSVValidators.SingleCharacterValidator();
+        Validator validator = CSVValidators.SINGLE_CHAR_VALIDATOR;
         ValidationContext mockContext = Mockito.mock(ValidationContext.class);
         ValidationResult result = validator.validate("EscapeChar", null, mockContext);
         assertEquals("Input is null for this property", result.getExplanation());
         assertFalse(result.isValid());
     }
 
+    @Test
+    public void testSingleCharEmptyValue() {
+        Validator validator = CSVValidators.SINGLE_CHAR_VALIDATOR;
+        ValidationContext mockContext = Mockito.mock(ValidationContext.class);
+        ValidationResult result = validator.validate("EscapeChar", "", mockContext);
+        assertEquals("Value must be exactly 1 character but was 0 in length", result.getExplanation());
+        assertFalse(result.isValid());
+    }
+
     @Test
     public void testSingleCharTab() {
-        CSVValidators.SingleCharacterValidator validator = new CSVValidators.SingleCharacterValidator();
+        Validator validator = CSVValidators.SINGLE_CHAR_VALIDATOR;
         ValidationContext mockContext = Mockito.mock(ValidationContext.class);
         ValidationResult result = validator.validate("EscapeChar", "\\t", mockContext);
         assertTrue(result.isValid());
@@ -50,24 +59,16 @@ public class TestCSVValidators {
 
     @Test
     public void testSingleCharIllegalChar() {
-        CSVValidators.SingleCharacterValidator validator = new CSVValidators.SingleCharacterValidator();
+        Validator validator = CSVValidators.SINGLE_CHAR_VALIDATOR;
         ValidationContext mockContext = Mockito.mock(ValidationContext.class);
         ValidationResult result = validator.validate("EscapeChar", "\\r", mockContext);
         assertEquals("\\r is not a valid character for this property", result.getExplanation());
         assertFalse(result.isValid());
     }
 
-    @Test
-    public void testSingleCharGoodChar() {
-        CSVValidators.SingleCharacterValidator validator = new CSVValidators.SingleCharacterValidator();
-        ValidationContext mockContext = Mockito.mock(ValidationContext.class);
-        ValidationResult result = validator.validate("EscapeChar", "'", mockContext);
-        assertTrue(result.isValid());
-    }
-
     @Test
     public void testSingleCharExpressionLanguage() {
-        CSVValidators.SingleCharacterValidator validator = new CSVValidators.SingleCharacterValidator();
+        Validator validator = CSVValidators.SINGLE_CHAR_VALIDATOR;
         ValidationContext mockContext = Mockito.mock(ValidationContext.class);
         Mockito.when(mockContext.isExpressionLanguageSupported(Mockito.any())).thenReturn(true);
         Mockito.when(mockContext.isExpressionLanguagePresent(Mockito.any())).thenReturn(true);
@@ -75,6 +76,66 @@ public class TestCSVValidators {
         assertTrue(result.isValid());
     }
 
+    @Test
+    public void testSingleCharGoodChar() {
+        Validator validator = CSVValidators.SINGLE_CHAR_VALIDATOR;
+        ValidationContext mockContext = Mockito.mock(ValidationContext.class);
+        ValidationResult result = validator.validate("EscapeChar", "'", mockContext);
+        assertTrue(result.isValid());
+    }
+
+    /*** Empty Or SingleCharValidator **/
+    @Test
+    public void testEmptySingleCharNullValue() {
+        Validator validator = CSVValidators.EMPTY_OR_SINGLE_CHAR_VALIDATOR;
+        ValidationContext mockContext = Mockito.mock(ValidationContext.class);
+        ValidationResult result = validator.validate("EscapeChar", null, mockContext);
+        assertEquals("Input is null for this property", result.getExplanation());
+        assertFalse(result.isValid());
+    }
+
+    @Test
+    public void testEmptySingleCharTab() {
+        Validator validator = CSVValidators.EMPTY_OR_SINGLE_CHAR_VALIDATOR;
+        ValidationContext mockContext = Mockito.mock(ValidationContext.class);
+        ValidationResult result = validator.validate("EscapeChar", "\\t", mockContext);
+        assertTrue(result.isValid());
+    }
+
+    @Test
+    public void testEmptySingleCharIllegalChar() {
+        Validator validator = CSVValidators.EMPTY_OR_SINGLE_CHAR_VALIDATOR;
+        ValidationContext mockContext = Mockito.mock(ValidationContext.class);
+        ValidationResult result = validator.validate("EscapeChar", "\\r", mockContext);
+        assertEquals("\\r is not a valid character for this property", result.getExplanation());
+        assertFalse(result.isValid());
+    }
+
+    @Test
+    public void testEmptySingleCharExpressionLanguage() {
+        Validator validator = CSVValidators.EMPTY_OR_SINGLE_CHAR_VALIDATOR;
+        ValidationContext mockContext = Mockito.mock(ValidationContext.class);
+        Mockito.when(mockContext.isExpressionLanguageSupported(Mockito.any())).thenReturn(true);
+        Mockito.when(mockContext.isExpressionLanguagePresent(Mockito.any())).thenReturn(true);
+        ValidationResult result = validator.validate("EscapeChar", "${csv.escape}", mockContext);
+        assertTrue(result.isValid());
+    }
+
+    @Test
+    public void testEmptySingleCharGoodChar() {
+        Validator validator = CSVValidators.EMPTY_OR_SINGLE_CHAR_VALIDATOR;
+        ValidationContext mockContext = Mockito.mock(ValidationContext.class);
+        ValidationResult result = validator.validate("EscapeChar", "'", mockContext);
+        assertTrue(result.isValid());
+    }
+
+    @Test
+    public void testEmptySingleCharEmptyChar() {
+        Validator validator = CSVValidators.EMPTY_OR_SINGLE_CHAR_VALIDATOR;
+        ValidationContext mockContext = Mockito.mock(ValidationContext.class);
+        ValidationResult result = validator.validate("EscapeChar", "", mockContext);
+        assertTrue(result.isValid());
+    }
 
     /*** Unescaped SingleCharValidator **/
 

nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/test/java/org/apache/nifi/csv/TestJacksonCSVRecordReader.java

@@ -402,7 +402,7 @@ public class TestJacksonCSVRecordReader {
     }
 
     @Test
-    public void testMultipleRecordsEscapedWithSpecialChar() throws IOException, MalformedRecordException {
+    public void testMultipleRecordsDelimitedWithSpecialChar() throws IOException, MalformedRecordException {
 
         char delimiter = StringEscapeUtils.unescapeJava("\u0001").charAt(0);
 
@@ -412,7 +412,7 @@ public class TestJacksonCSVRecordReader {
 
         final RecordSchema schema = new SimpleRecordSchema(fields);
 
-        try (final InputStream fis = new FileInputStream("src/test/resources/csv/multi-bank-account_escapedchar.csv");
+        try (final InputStream fis = new FileInputStream("src/test/resources/csv/multi-bank-account_spec_delimiter.csv");
             final JacksonCSVRecordReader reader = createReader(fis, schema, format)) {
 
             final Object[] firstRecord = reader.nextRecord().getValues();
@@ -427,6 +427,46 @@ public class TestJacksonCSVRecordReader {
         }
     }
 
+    @Test
+    public void testMultipleRecordsEscapedWithChar() throws IOException {
+
+        final CSVFormat format = CSVFormat.DEFAULT.withFirstRecordAsHeader().withTrim().withQuote('"').withDelimiter(",".charAt(0)).withEscape("\\".charAt(0));
+        final List<RecordField> fields = getDefaultFields();
+        fields.replaceAll(f -> f.getFieldName().equals("balance") ? new RecordField("balance", doubleDataType) : f);
+
+        final RecordSchema schema = new SimpleRecordSchema(fields);
+
+        try (final InputStream fis = new FileInputStream("src/test/resources/csv/multi-bank-account_escapechar.csv");
+             final JacksonCSVRecordReader reader = createReader(fis, schema, format)) {
+
+            assertThrows(NumberFormatException.class, () -> reader.nextRecord());
+        }
+    }
+
+    @Test
+    public void testMultipleRecordsEscapedWithNull() throws IOException, MalformedRecordException {
+
+        final CSVFormat format = CSVFormat.DEFAULT.withFirstRecordAsHeader().withTrim().withQuote('"').withDelimiter(",".charAt(0)).withEscape(null);
+        final List<RecordField> fields = getDefaultFields();
+        fields.replaceAll(f -> f.getFieldName().equals("balance") ? new RecordField("balance", doubleDataType) : f);
+
+        final RecordSchema schema = new SimpleRecordSchema(fields);
+
+        try (final InputStream fis = new FileInputStream("src/test/resources/csv/multi-bank-account_escapechar.csv");
+             final JacksonCSVRecordReader reader = createReader(fis, schema, format)) {
+
+            final Object[] firstRecord = reader.nextRecord().getValues();
+            final Object[] firstExpectedValues = new Object[] {"1", "John Doe\\", 4750.89D, "123 My Street", "My City", "MS", "11111", "USA"};
+            Assert.assertArrayEquals(firstExpectedValues, firstRecord);
+
+            final Object[] secondRecord = reader.nextRecord().getValues();
+            final Object[] secondExpectedValues = new Object[] {"2", "Jane Doe", 4820.09D, "321 Your Street", "Your City", "NY", "33333", "USA"};
+            Assert.assertArrayEquals(secondExpectedValues, secondRecord);
+
+            assertNull(reader.nextRecord());
+        }
+    }
+
     @Test
     public void testNullRecordSeparator() throws IOException, MalformedRecordException {
         final List<RecordField> fields = getDefaultFields();

nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/test/java/org/apache/nifi/csv/TestWriteCSVResult.java

@@ -330,6 +330,62 @@ public class TestWriteCSVResult {
         assertEquals("id,name,dob\n1,,1/1/1970\n", output);
     }
 
+    @Test
+    public void testEscapeCharInValueWriteRecord() throws IOException {
+        final CSVFormat csvFormat = CSVFormat.DEFAULT.withEscape('\\').withQuote("\"".charAt(0)).withRecordSeparator("\n");
+        final List<RecordField> fields = new ArrayList<>();
+        fields.add(new RecordField("id", RecordFieldType.STRING.getDataType()));
+        fields.add(new RecordField("name", RecordFieldType.STRING.getDataType()));
+        final RecordSchema schema = new SimpleRecordSchema(fields);
+
+        final Map<String, Object> values = new LinkedHashMap<>();
+        values.put("id", "1\\");
+        values.put("name", "John Doe");
+        final Record record = new MapRecord(schema, values);
+
+        final ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        final String output;
+        try (final WriteCSVResult writer = new WriteCSVResult(csvFormat, schema, new SchemaNameAsAttribute(), baos,
+                RecordFieldType.DATE.getDefaultFormat(), RecordFieldType.TIME.getDefaultFormat(), RecordFieldType.TIMESTAMP.getDefaultFormat(), true, "ASCII")) {
+
+            writer.beginRecordSet();
+            writer.write(record);
+            writer.finishRecordSet();
+            writer.flush();
+            output = baos.toString();
+        }
+
+        assertEquals("id,name\n\"1\\\\\",John Doe\n", output);
+    }
+
+    @Test
+    public void testEmptyEscapeCharWriteRecord() throws IOException {
+        final CSVFormat csvFormat = CSVFormat.DEFAULT.withEscape(null).withQuote("\"".charAt(0)).withRecordSeparator("\n");
+        final List<RecordField> fields = new ArrayList<>();
+        fields.add(new RecordField("id", RecordFieldType.STRING.getDataType()));
+        fields.add(new RecordField("name", RecordFieldType.STRING.getDataType()));
+        final RecordSchema schema = new SimpleRecordSchema(fields);
+
+        final Map<String, Object> values = new LinkedHashMap<>();
+        values.put("id", "1\\");
+        values.put("name", "John Doe");
+        final Record record = new MapRecord(schema, values);
+
+        final ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        final String output;
+        try (final WriteCSVResult writer = new WriteCSVResult(csvFormat, schema, new SchemaNameAsAttribute(), baos,
+                RecordFieldType.DATE.getDefaultFormat(), RecordFieldType.TIME.getDefaultFormat(), RecordFieldType.TIMESTAMP.getDefaultFormat(), true, "ASCII")) {
+
+            writer.beginRecordSet();
+            writer.write(record);
+            writer.finishRecordSet();
+            writer.flush();
+            output = baos.toString();
+        }
+
+        assertEquals("id,name\n1\\,John Doe\n", output);
+    }
+
 
     private DateFormat getDateFormat(final String format) {
         final DateFormat df = new SimpleDateFormat(format);

nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/test/resources/csv/multi-bank-account_escapechar.csv

@@ -0,0 +1,3 @@
+id, name, balance, address, city, state, zipCode, country
+1, John Doe\, "4750.89", "123 My Street", My City, MS, 11111, USA
+2, Jane Doe, 4820.09, 321 Your Street, Your City, NY, 33333, USA