Fix writer flushing

nbbrd · Mar 26, 2024 · 08dc604 · 08dc604
1 parent 88223fe
commit 08dc604
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Showing 3 changed files with 32 additions and 5 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- Fix writer flushing [#217](https://github.com/nbbrd/picocsv/issues/217)
+
 ## [2.3.0] - 2024-03-12
 
 This is a feature release of **picocsv**.   

diff --git a/src/main/java/nbbrd/picocsv/Csv.java b/src/main/java/nbbrd/picocsv/Csv.java
@@ -1281,6 +1281,7 @@ public void flush() throws IOException {
                 output.write(quote);
             }
             state = STATE_NO_FIELD;
+            output.flush();
         }
 
         /**
@@ -1349,7 +1350,7 @@ private int getQuoting(CharSequence field) {
         private static final int STATE_SINGLE_EMPTY_FIELD = 1;
         private static final int STATE_MULTI_FIELD = 2;
 
-        private static final class Output implements Closeable {
+        private static final class Output implements Closeable, Flushable {
 
             private final java.io.Writer charWriter;
             private final char[] buffer;
@@ -1363,15 +1364,15 @@ private Output(java.io.Writer charWriter, char[] charBuffer) {
 
             public void write(char c) throws IOException {
                 if (length == buffer.length) {
-                    flush();
+                    flushBuffer();
                 }
                 buffer[length++] = c;
             }
 
             public void write(CharSequence chars) throws IOException {
                 int charsLength = chars.length();
                 if (length + charsLength >= buffer.length) {
-                    flush();
+                    flushBuffer();
                     if (charsLength >= buffer.length) {
                         charWriter.append(chars);
                         return;
@@ -1389,14 +1390,22 @@ public void write(CharSequence chars) throws IOException {
 
             @Override
             public void close() throws IOException {
-                flush();
+                flushBuffer();
                 charWriter.close();
             }
 
-            private void flush() throws IOException {
+            private void flushBuffer() throws IOException {
                 charWriter.write(buffer, 0, length);
                 length = 0;
             }
+
+            @Override
+            public void flush() throws IOException {
+                if (length != 0) {
+                    flushBuffer();
+                }
+                charWriter.flush();
+            }
         }
 
         private static abstract class EndOfLineEncoder {

diff --git a/src/test/java/nbbrd/picocsv/CsvWriterTest.java b/src/test/java/nbbrd/picocsv/CsvWriterTest.java
@@ -221,6 +221,20 @@ public void testOutputBuffer() throws IOException {
         ), Csv.WriterOptions.DEFAULT);
     }
 
+    @Test
+    void flushesALineToTheUnderlyingWriter() throws IOException {
+        StringWriter buf = new StringWriter();
+
+        Csv.Writer csvWriter = Csv.Writer.of(Csv.Format.RFC4180, Csv.WriterOptions.DEFAULT, buf);
+        csvWriter.writeField("foo");
+        csvWriter.writeField("bar");
+        csvWriter.writeField("baz");
+        csvWriter.writeEndOfLine();
+        csvWriter.flush();
+
+        assertThat(buf.toString()).isEqualTo("foo,bar,baz\r\n");
+    }
+
     private static Sample getOverflowSample(String... fields) {
         return Sample
                 .builder()