Add a hexadecimal codec.

test/hex_test.dart

+// Copyright (c) 2015, 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.
+
+import 'dart:async';
+
+import 'package:convert/convert.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group("encoder", () {
+    test("converts byte arrays to hex", () {
+      expect(hex.encode([0x1a, 0xb2, 0x3c, 0xd4]), equals("1ab23cd4"));
+      expect(hex.encode([0x00, 0x01, 0xfe, 0xff]), equals("0001feff"));
+    });
+
+    group("with chunked conversion", () {
+      test("converts byte arrays to hex", () {
+        var results = [];
+        var controller = new StreamController(sync: true);
+        controller.stream.listen(results.add);
+        var sink = hex.encoder.startChunkedConversion(controller.sink);
+
+        sink.add([0x1a, 0xb2, 0x3c, 0xd4]);
+        expect(results, equals(["1ab23cd4"]));
+
+        sink.add([0x00, 0x01, 0xfe, 0xff]);
+        expect(results, equals(["1ab23cd4", "0001feff"]));
+      });
+
+      test("handles empty and single-byte lists", () {
+        var results = [];
+        var controller = new StreamController(sync: true);
+        controller.stream.listen(results.add);
+        var sink = hex.encoder.startChunkedConversion(controller.sink);
+
+        sink.add([]);
+        expect(results, equals([""]));
+
+        sink.add([0x00]);
+        expect(results, equals(["", "00"]));
+
+        sink.add([]);
+        expect(results, equals(["", "00", ""]));
+      });
+    });
+
+    test("rejects non-bytes", () {
+      expect(() => hex.encode([0x100]), throwsFormatException);
+
+      var sink = hex.encoder.startChunkedConversion(
+          new StreamController(sync: true));
+      expect(() => sink.add([0x100]), throwsFormatException);
+    });
+  });
+
+  group("decoder", () {
+    test("converts hex to byte arrays", () {
+      expect(hex.decode("1ab23cd4"), equals([0x1a, 0xb2, 0x3c, 0xd4]));
+      expect(hex.decode("0001feff"), equals([0x00, 0x01, 0xfe, 0xff]));
+    });
+
+    test("supports uppercase letters", () {
+      expect(hex.decode("0123456789ABCDEFabcdef"), equals([
+        0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xab, 0xcd, 0xef
+      ]));
+    });
+
+    group("with chunked conversion", () {
+      var results;
+      var sink;
+      setUp(() {
+        results = [];
+        var controller = new StreamController(sync: true);
+        controller.stream.listen(results.add);
+        sink = hex.decoder.startChunkedConversion(controller.sink);
+      });
+
+      test("converts hex to byte arrays", () {
+        sink.add("1ab23cd4");
+        expect(results, equals([[0x1a, 0xb2, 0x3c, 0xd4]]));
+
+        sink.add("0001feff");
+        expect(results,
+            equals([[0x1a, 0xb2, 0x3c, 0xd4], [0x00, 0x01, 0xfe, 0xff]]));
+      });
+
+      test("supports trailing digits split across chunks", () {
+        sink.add("1ab23");
+        expect(results, equals([[0x1a, 0xb2]]));
+
+        sink.add("cd");
+        expect(results, equals([[0x1a, 0xb2], [0x3c]]));
+
+        sink.add("40001");
+        expect(results, equals([[0x1a, 0xb2], [0x3c], [0xd4, 0x00, 0x01]]));
+
+        sink.add("feff");
+        expect(results,
+            equals([[0x1a, 0xb2], [0x3c], [0xd4, 0x00, 0x01], [0xfe, 0xff]]));
+      });
+
+      test("supports empty strings", () {
+        sink.add("");
+        expect(results, equals([[]]));
+
+        sink.add("00");
+        expect(results, equals([[], [0x00]]));
+
+        sink.add("");
+        expect(results, equals([[], [0x00], []]));
+      });
+
+      test("rejects odd length detected in close()", () {
+        sink.add("1ab23");
+        expect(results, equals([[0x1a, 0xb2]]));
+        expect(() => sink.close(), throwsFormatException);
+      });
+
+      test("rejects odd length detected in addSlice()", () {
+        sink.addSlice("1ab23cd", 0, 5, false);
+        expect(results, equals([[0x1a, 0xb2]]));
+
+        expect(() => sink.addSlice("1ab23cd", 5, 7, true),
+            throwsFormatException);
+      });
+    });
+
+    group("rejects non-hex character", () {
+      for (var char in
+             ["g", "G", "/", ":", "@", "`", "\x00", "\u0141", "\u{10041}"]) {
+        test('"$char"', () {
+          expect(() => hex.decode("a$char"), throwsFormatException);
+
+          var sink = hex.decoder.startChunkedConversion(
+              new StreamController(sync: true));
+          expect(() => sink.add("a$char"), throwsFormatException);

[Lasse Reichstein Nielsen, 2015/09/24 08:07:02]

Also try them as first digit and as the single digit in a chunked conversion.

[nweiz, 2015/09/24 23:23:42]

Done.

+        });
+      }
+    });
+
+    test("rejects odd characters detected in convert()", () {

[Lasse Reichstein Nielsen, 2015/09/24 08:07:02]

odd characters -> odd length

[nweiz, 2015/09/24 23:23:42]

Done.

+      expect(() => hex.decode("1ab23cd"), throwsFormatException);
+    });
+  });
+}