Add jsonDecode, jsonEncode, base64Decode, base64Encode, base64UrlEncode functions.

Change-Id: Ic65ada3b107cc8e6c3459459c4bea389feef2168
Reviewed-on: https://dart-review.googlesource.com/23664
Commit-Queue: Lasse R.H. Nielsen <lrn@google.com>
Reviewed-by: Lasse R.H. Nielsen <lrn@google.com>
Reviewed-by: Leaf Petersen <leafp@google.com>

CHANGELOG.md

@@ -1,10 +1,13 @@
 
 ### Core library changes
 
-* Temporarily disabled the `whereType` method until generic methods are enabled
-  on all platforms ([issue 32463]).
-
-[issue 32463]: https://github.com/dart-lang/sdk/issues/32463
+* `dart:core`
+  * Temporarily disabled the `whereType` method until generic methods are
+    enabled on all platforms
+    ([issue 32463](https://github.com/dart-lang/sdk/issues/32463)).
+* `dart:convert`
+  * Added `jsonEncode`, `jsonDecode`, `base64Encode`, `base64UrlEncode` and
+    `base64Decode` top-level functions.
 
 ## 2.0.0
 

sdk/lib/convert/base64.dart

@@ -38,6 +38,27 @@ const Base64Codec base64Url = const Base64Codec.urlSafe();
 @Deprecated("Use base64Url instead")
 const Base64Codec BASE64URL = base64Url;
 
+/**
+ * Encodes [bytes] using [base64](https://tools.ietf.org/html/rfc4648) encoding.
+ *
+ * Shorthand for [base64.encode].
+ */
+String base64Encode(List<int> bytes) => base64.encode(bytes);
+
+/**
+ * Encodes [bytes] using [base64url](https://tools.ietf.org/html/rfc4648) encoding.
+ *
+ * Shorthand for [base64url.encode].
+ */
+String base64UrlEncode(List<int> bytes) => base64Url.encode(bytes);
+
+/**
+ * Decodes [base64](https://tools.ietf.org/html/rfc4648) or [base64url](https://tools.ietf.org/html/rfc4648) encoded bytes.
+ *
+ * Shorthand for [base64.decode].
+ */
+List<int> base64Decode(String source) => base64.decode(source);
+
 // Constants used in more than one class.
 const int _paddingChar = 0x3d; // '='.
 

sdk/lib/convert/json.dart

@@ -69,6 +69,37 @@ const JsonCodec json = const JsonCodec();
 @Deprecated("Use json instead")
 const JsonCodec JSON = json;
 
+/**
+ * Converts [value] to a JSON string.
+ *
+ * If value contains objects that are not directly encodable to a JSON
+ * string (a value that is not a number, boolean, string, null, list or a map
+ * with string keys), the [toEncodable] function is used to convert it to an
+ * object that must be directly encodable.
+ *
+ * If [toEncodable] is omitted, it defaults to a function that returns the
+ * result of calling `.toJson()` on the unencodable object.
+ *
+ * Shorthand for [json.encode].
+ */
+String jsonEncode(Object object, {Object toEncodable(Object nonEncodable)}) =>
+    json.encode(object, toEncodable: toEncodable);
+
+/**
+ * Parses the string and returns the resulting Json object.
+ *
+ * The optional [reviver] function is called once for each object or list
+ * property that has been parsed during decoding. The `key` argument is either
+ * the integer list index for a list property, the string map key for object
+ * properties, or `null` for the final result.
+ *
+ * The default [reviver] (when not provided) is the identity function.
+ *
+ * Shorthand for [json.decode].
+ */
+dynamic jsonDecode(String source, {Object reviver(Object key, Object value)}) =>
+    json.decode(source, reviver: reviver);
+
 typedef _Reviver(Object key, Object value);
 typedef _ToEncodable(var o);
 

tests/lib_2/convert/base64_test.dart

@@ -107,6 +107,10 @@ void testRoundtrip(List<int> list, String name) {
       }
     }
   }
+  // Using .encode
+  Expect.equals(uriEncoded, base64Url.encode(list), ".encode($list)");
+  // Using base64UrlEncode
+  Expect.equals(uriEncoded, base64UrlEncode(list), ".encode($list)");
 
   for (var encoded in [encodedNormal, encodedPercent, uriEncoded]) {
     increment = encoded.length ~/ 7 + 1;
@@ -141,6 +145,9 @@ void testRoundtrip(List<int> list, String name) {
         }
       }
     }
+    Expect.listEquals(list, base64.decode(encoded), ".decode($encoded)");
+    Expect.listEquals(list, base64Url.decode(encoded), "url.decode($encoded)");
+    Expect.listEquals(list, base64Decode(encoded), "base64Decode($encoded)");
   }
 }
 

tests/lib_2/convert/json_test.dart

@@ -35,7 +35,7 @@ void testJson(jsonText, expected) {
   }
 
   for (var reviver in [null, (k, v) => v]) {
-    for (var split in [0, 1, 2, 3]) {
+    for (var split in [0, 1, 2, 3, 4, 5]) {
       var name = (reviver == null) ? "" : "reviver:";
       var sink = new ChunkedConversionSink.withCallback((values) {
         var value = values[0];
@@ -72,6 +72,14 @@ void testJson(jsonText, expected) {
           decoderSink.add(jsonText.substring(2 * third));
           decoderSink.close();
           break;
+        case 4:
+          // Use .decode
+          sink.add([json.decode(jsonText)]);
+          break;
+        case 5:
+          // Use jsonDecode
+          sink.add([jsonDecode(jsonText)]);
+          break;
       }
     }
   }
@@ -98,6 +106,8 @@ String escape(String s) {
 void testThrows(jsonText) {
   Expect.throwsFormatException(() => json.decode(jsonText),
       "json = '${escape(jsonText)}'");
+  Expect.throwsFormatException(() => jsonDecode(jsonText),
+      "json = '${escape(jsonText)}'");
 }
 
 testNumbers() {
@@ -187,6 +197,9 @@ testNumbers() {
   Expect.throws(() => json.encode(double.nan));
   Expect.throws(() => json.encode(double.infinity));
   Expect.throws(() => json.encode(double.negativeInfinity));
+  Expect.throws(() => jsonEncode(double.nan));
+  Expect.throws(() => jsonEncode(double.infinity));
+  Expect.throws(() => jsonEncode(double.negativeInfinity));
 }
 
 testStrings() {