Make JSON parsing work as a chunked conversion sink.

tests/lib/convert/json_chunk_test.dart

+// Copyright (c) 2014, 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 json_test;
+
+import "package:expect/expect.dart";
+import "dart:convert";
+
+bool badFormat(e) => e is FormatException;
+
+jsonTest(name, expect, action(sink)) {

[Søren Gjesse, 2014/10/24 11:12:24]

name -> testName or nameOftest

[Lasse Reichstein Nielsen, 2014/10/27 12:42:34]

testName.

+  var sink = new ChunkedConversionSink.withCallback((values) {
+    var value = values[0];
+    Expect.equals(expect, value, "$name$value");

[Søren Gjesse, 2014/10/24 11:12:24]

Separator before $value

[Lasse Reichstein Nielsen, 2014/10/27 12:42:33]

Done.

+  });
+  var decoderSink = JSON.decoder.startChunkedConversion(sink);
+  action(decoderSink);
+}
+
+main() {
+  testNumbers();
+  testStrings();
+  testKeywords();
+}
+
+void testStrings() {
+  var s = r'"abc\f\n\r\t\b\"\/\\\u0001\u9999\uffff"';
+  var expected = "abc\f\n\r\t\b\"\/\\\u0001\u9999\uffff";
+  for (var i = 1; i < s.length - 1; i++) {
+    var s1 = s.substring(0, i);
+    var s2 = s.substring(i);
+    jsonTest("$s1|$s2", expected, (sink) {
+      sink.add(s1);
+      sink.add(s2);
+      sink.close();
+    });
+    jsonTest("$s1|$s2", expected, (sink) {
+      sink.addSlice(s, 0, i, false);
+      sink.addSlice(s, i, s.length, true);
+    });
+    for (var j = i; j < s.length - 1; j++) {
+      var s2a = s.substring(i, j);
+      var s2b = s.substring(j);
+      jsonTest("$s1|$s2a|$s2b", expected, (sink) {
+        sink.add(s1);
+        sink.add(s2a);
+        sink.add(s2b);
+        sink.close();
+      });
+    }
+  }
+}
+
+void testNumbers() {
+  for (var number in ["-0.12e-12", "-34.12E+12", "0.0e0", "9.9E9"]) {

[Søren Gjesse, 2014/10/24 11:12:24]

How about more numbers as in the other test. Just .1 is not legal, right?

[Lasse Reichstein Nielsen, 2014/10/27 12:42:33]

Adding more numbers.
The important part here is to have splits at all possible number states, but
I'll ensure that we also test numbers without exponent etc.

No, ".1" isn't valid JSON. (I wouldn't say "illegal" - it's just a spec, not a
law! - pet peeve :).

I'll add some negative tests too, to ensure that we don't, e.g., allow leading
zeros across chunk splits.

+    var expected = double.parse(number);
+    for (int i = 1; i < number.length - 1; i++) {
+      var p1 = number.substring(0, i);
+      var p2 = number.substring(i);
+      jsonTest("$p1|$p2", expected, (sink) {
+        sink.add(p1);
+        sink.add(p2);
+        sink.close();
+      });
+
+      jsonTest("$p1|$p2/slice", expected, (sink) {
+        sink.addSlice(number, 0, i, false);
+        sink.addSlice(number, i, number.length, true);
+      });
+
+      for (int j = i; j < number.length - 1; j++) {
+        var p2a = number.substring(i, j);
+        var p2b = number.substring(j);
+        jsonTest("$p1|$p2a|$p2b", expected, (sink) {
+          sink.add(p1);
+          sink.add(p2a);
+          sink.add(p2b);
+          sink.close();
+        });
+      }
+    }
+  }
+}
+
+void testKeywords() {
+  for (var expected in [null, true, false]) {
+    var s = "$expected";
+    for (int i = 1; i < s.length - 1; i++) {
+      var s1 = s.substring(0, i);
+      var s2 = s.substring(i);
+      jsonTest("$s1|$s2", expected, (sink) {
+        sink.add(s1);
+        sink.add(s2);
+        sink.close();
+      });
+      jsonTest("$s1|$s2", expected, (sink) {
+        sink.addSlice(s, 0, i, false);
+        sink.addSlice(s, i, s.length, true);
+      });
+      for (var j = i; j < s.length - 1; j++) {
+        var s2a = s.substring(i, j);
+        var s2b = s.substring(j);
+        jsonTest("$s1|$s2a|$s2b", expected, (sink) {
+          sink.add(s1);
+          sink.add(s2a);
+          sink.add(s2b);
+          sink.close();
+        });
+      }
+    }
+  }
+}