convert: new LineSplitter, (io: Deprecate LineTransformer)

tests/lib/convert/line_splitter_test.dart

+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library line_splitter_test;
+import "package:expect/expect.dart";
+import 'dart:async';
+import 'dart:convert';
+import 'dart:math' as MATH;
+
+
+void main() {
+  testSimpleConvert();
+  testManyLines();
+  testReadLine1();
+  testReadLine2();
+}
+
+void testManyLines() {
+  const breaks = const ['\n', '\r\n'];
+  int breakIndex = 0;
+
+  var inputs = const ['line1', 'line2', 'long line 3', ' this is line 4 ', 'l5'];

[floitsch, 2013/08/07 12:58:26]

80chars.

[kevmoo-old, 2013/08/07 17:13:41]

Done.

+
+
+  var buffer = inputs.fold(new StringBuffer(), (buff, e) {
+    buff.write(e);
+    buff.write(breaks[breakIndex]);
+
+    breakIndex++;
+    breakIndex = breakIndex % breaks.length;
+
+    return buff;
+  });
+
+
+  var foo = _getLinesSliced(buffer.toString());
+  Expect.equals(inputs.join(), foo);
+}
+
+
+String _getLinesSliced(String str) {
+  String lines;
+  ChunkedConversionSink byteSink =

[floitsch, 2013/08/07 12:58:26]

Rename byteSink to stringSink.

[kevmoo-old, 2013/08/07 17:13:41]

Done.

+      new StringConversionSink.withCallback((result) => lines = result);
+  var stringConversionSink = new LineSplitter().startChunkedConversion(byteSink);

[floitsch, 2013/08/07 12:58:26]

80chars.

[kevmoo-old, 2013/08/07 17:13:41]

Done.

+
+  const chunkSize = 3;
+  var index = 0;
+  while(index < str.length) {
+    var end = MATH.min(str.length, index + chunkSize);
+
+    stringConversionSink.addSlice(str, index, end, false);
+    index += chunkSize;
+  }
+
+  stringConversionSink.close();
+  return lines;
+}
+
+void testSimpleConvert() {
+  var test = """line1
+line2
+line3""";
+
+
+  var decoder = new LineSplitter();
+  var result = decoder.convert(test);
+
+  Expect.listEquals(['line1', 'line2', 'line3'], result);
+
+  test = "Line1\nLine2\r\nLine3\rLi"
+      "ne4\n"
+       "\n\n\r\n\r\n\r\r";
+
+  result = decoder.convert(test);
+
+  Expect.listEquals(
+      ['Line1', 'Line2', 'Line3', 'Line4', '', '', '', '', '', ''],
+      result);
+}
+
+void testReadLine1() {
+  var controller = new StreamController(sync: true);
+  var stream = controller.stream
+      .transform(new Utf8Decoder())
+      .transform(new LineSplitter());
+
+  var stage = 0;
+  var done = false;
+
+  void stringData(line) {
+    Expect.equals(stage, 0);
+    Expect.equals("Line", line);
+    stage++;
+  }
+
+  void streamClosed() {
+    Expect.equals(1, stage);
+    done = true;
+  }
+
+  stream.listen(
+      stringData,
+      onDone: streamClosed);
+
+  controller.add("Line".codeUnits);

[floitsch, 2013/08/07 12:58:26]

Add comment that UTF8 is ok, because the string is only ASCII.

[kevmoo-old, 2013/08/07 17:13:41]

Done.

+  controller.close();
+  Expect.isTrue(done, 'should be done by now');
+}
+
+void testReadLine2() {
+  var controller = new StreamController(sync: true);
+
+  var stream = controller.stream
+    .transform(new Utf8Decoder())
+    .transform(new LineSplitter());
+
+  var done = false;
+
+  var stage = 0;
+  var subStage = 0;
+  stream.listen((line) {
+      if (stage == 0) {
+        if (subStage == 0) {
+          Expect.equals("Line1", line);
+          subStage++;
+        } else if (subStage == 1) {
+          Expect.equals("Line2", line);
+          subStage++;
+        } else if (subStage == 2) {
+          Expect.equals("Line3", line);
+          subStage = 0;
+          stage++;
+        } else {
+          Expect.fail("Stage 0 failed");
+        }
+      } else if (stage == 1) {
+        if (subStage == 0) {
+          Expect.equals("Line4", line);
+          subStage = 0;
+          stage++;
+        } else {
+          Expect.fail("Stage 1 failed");
+        }
+      } else if (stage == 2) {
+        if (subStage < 4) {
+          // Expect 5 empty lines. As long as the stream is not closed the
+          // final \r cannot be interpreted as a end of line.
+          Expect.equals("", line);
+          subStage++;
+        } else if (subStage == 4) {
+          Expect.equals("", line);
+          subStage = 0;
+          stage++;
+        } else {
+          Expect.fail("Stage 2 failed");
+        }
+      } else if (stage == 3) {
+        if (subStage == 0) {
+          Expect.equals("", line);
+          stage++;
+        } else {
+          Expect.fail("Stage 3 failed");
+        }
+      }
+    }, onDone: () {
+      Expect.equals(4, stage);
+      Expect.equals(0, subStage);
+      done = true;
+    });
+
+  controller.add("Line1\nLine2\r\nLine3\rLi".codeUnits);

[floitsch, 2013/08/07 12:58:26]

Add comment that "codeUnits" is ok, because the string only contains ASCII.

[kevmoo-old, 2013/08/07 17:13:41]

Done.

+  controller.add("ne4\n".codeUnits);
+  controller.add("\n\n\r\n\r\n\r\r".codeUnits);
+  controller.close();
+  Expect.isTrue(done, 'should be done here...');
+}