Uncomment some tests

These tests had been commented out since the original commit in this
repo even though most of them would pass.

With these tests commented out the suite has an empty `group` which may
become disallowed.
dart-lang/test#1961

Change double quotes to single quotes.

Skip a test which is currently failing due to an error parsing a float
value with a single digit.

CHANGELOG.md

@@ -1,3 +1,5 @@
+## 3.1.3-wip
+
 ## 3.1.2
 
 * Require Dart 2.19

pubspec.yaml

@@ -1,5 +1,5 @@
 name: yaml
-version: 3.1.2
+version: 3.1.3-wip
 description: A parser for YAML, a human-friendly data serialization standard
 repository: https://github.com/dart-lang/yaml
 topics:

test/yaml_test.dart

@@ -1804,70 +1804,66 @@ void main() {
   });
 
   group('10.2: JSON Schema', () {
-    // test('[Example 10.4]', () {
-    //   var doc = deepEqualsMap({"key with null value": null});
-    //   doc[null] = "value for null key";
-    //   expectYamlStreamLoads(doc,
-    //     """
-    //     !!null null: value for null key
-    //     key with null value: !!null null""");
-    // });
-
-    // test('[Example 10.5]', () {
-    //   expectYamlStreamLoads({
-    //     "YAML is a superset of JSON": true,
-    //     "Pluto is a planet": false
-    //   },
-    //     """
-    //     YAML is a superset of JSON: !!bool true
-    //     Pluto is a planet: !!bool false""");
-    // });
+    test('[Example 10.4]', () {
+      var doc = deepEqualsMap({'key with null value': null});
+      doc[null] = 'value for null key';
+      expectYamlStreamLoads([doc], '''
+        !!null null: value for null key
+        key with null value: !!null null''');
+    });
 
-    // test('[Example 10.6]', () {
-    //   expectYamlStreamLoads({
-    //     "negative": -12,
-    //     "zero": 0,
-    //     "positive": 34
-    //   },
-    //     """
-    //     negative: !!int -12
-    //     zero: !!int 0
-    //     positive: !!int 34""");
-    // });
+    test('[Example 10.5]', () {
+      expectYamlStreamLoads([
+        {'YAML is a superset of JSON': true, 'Pluto is a planet': false}
+      ], '''
+        YAML is a superset of JSON: !!bool true
+        Pluto is a planet: !!bool false''');
+    });
 
-    // test('[Example 10.7]', () {
-    //   expectYamlStreamLoads({
-    //     "negative": -1,
-    //     "zero": 0,
-    //     "positive": 23000,
-    //     "infinity": infinity,
-    //     "not a number": nan
-    //   },
-    //     """
-    //     negative: !!float -1
-    //     zero: !!float 0
-    //     positive: !!float 2.3e4
-    //     infinity: !!float .inf
-    //     not a number: !!float .nan""");
-    // });
+    test('[Example 10.6]', () {
+      expectYamlStreamLoads([
+        {'negative': -12, 'zero': 0, 'positive': 34}
+      ], '''
+        negative: !!int -12
+        zero: !!int 0
+        positive: !!int 34''');
+    });
 
-    // test('[Example 10.8]', () {
-    //   expectYamlStreamLoads({
-    //     "A null": null,
-    //     "Booleans": [true, false],
-    //     "Integers": [0, -0, 3, -19],
-    //     "Floats": [0, 0, 12000, -200000],
-    //     // Despite being invalid in the JSON schema, these values are valid in
-    //     // the core schema which this implementation supports.
-    //     "Invalid": [ true, null, 7, 0x3A, 12.3]
-    //   },
-    //     """
-    //     A null: null
-    //     Booleans: [ true, false ]
-    //     Integers: [ 0, -0, 3, -19 ]
-    //     Floats: [ 0., -0.0, 12e03, -2E+05 ]
-    //     Invalid: [ True, Null, 0o7, 0x3A, +12.3 ]""");
-    // });
+    test('[Example 10.7]', () {
+      expectYamlStreamLoads([
+        {
+          'negative': -1,
+          'zero': 0,
+          'positive': 23000,
+          'infinity': infinity,
+          'not a number': nan
+        }
+      ], '''
+        negative: !!float -1
+        zero: !!float 0
+        positive: !!float 2.3e4
+        infinity: !!float .inf
+        not a number: !!float .nan''');
+    }, skip: 'Fails for single digit float');
+
+    test('[Example 10.8]', () {
+      expectYamlStreamLoads([
+        {
+          'A null': null,
+          'Booleans': [true, false],
+          'Integers': [0, -0, 3, -19],
+          'Floats': [0, 0, 12000, -200000],
+          // Despite being invalid in the JSON schema, these values are valid in
+          // the core schema which this implementation supports.
+          'Invalid': [true, null, 7, 0x3A, 12.3]
+        }
+      ], '''
+        A null: null
+        Booleans: [ true, false ]
+        Integers: [ 0, -0, 3, -19 ]
+        Floats: [ 0., -0.0, 12e03, -2E+05 ]
+        Invalid: [ True, Null, 0o7, 0x3A, +12.3 ]''');
+    });
   });
 
   group('10.3: Core Schema', () {