Fix newly enforced package:pedantic lints (flutter#123)

- prefer_single_quotes
- prefer_spread_collections
- unused_field
- use_function_type_syntax_for_parameters

Bump min sdk to 2.3.0 to allow for spreads in collection literals.

Drop unused author field from pubspec.

.travis.yml

@@ -1,7 +1,7 @@
 language: dart
 
 dart:
-  - 2.2.0
+  - 2.3.0
   - dev
 
 dart_task:

lib/src/core_matchers.dart

@@ -160,7 +160,7 @@ class _ReturnsNormally extends FeatureMatcher<Function> {
 
   @override
   Description describe(Description description) =>
-      description.add("return normally");
+      description.add('return normally');
 
   @override
   Description describeTypedMismatch(Function item,
@@ -305,7 +305,7 @@ class _In<T> extends FeatureMatcher<T> {
 /// For example:
 ///
 ///     expect(v, predicate((x) => ((x % 2) == 0), "is even"))
-Matcher predicate<T>(bool f(T value),
+Matcher predicate<T>(bool Function(T) f,
         [String description = 'satisfies function']) =>
     _Predicate(f, description);
 

lib/src/equals_matcher.dart

@@ -228,7 +228,7 @@ class _DeepMatcher extends Matcher {
     }
 
     // We're not adding any value to the actual value.
-    return ["", location];
+    return ['', location];
   }
 
   String _match(expected, actual, Map matchState) {
@@ -237,7 +237,7 @@ class _DeepMatcher extends Matcher {
     String reason;
     if (rp[0].isNotEmpty) {
       if (rp[1].isNotEmpty) {
-        reason = "${rp[0]} at location ${rp[1]}";
+        reason = '${rp[0]} at location ${rp[1]}';
       } else {
         reason = rp[0];
       }

lib/src/having_matcher.dart

@@ -14,16 +14,17 @@ class HavingMatcher<T> implements TypeMatcher<T> {
   final List<_FunctionMatcher> _functionMatchers;
 
   HavingMatcher(TypeMatcher<T> parent, String description,
-      Object feature(T source), Object matcher,
+      Object Function(T) feature, Object matcher,
       [Iterable<_FunctionMatcher> existing])
       : _parent = parent,
-        _functionMatchers = <_FunctionMatcher>[]
-          ..addAll(existing ?? [])
-          ..add(_FunctionMatcher<T>(description, feature, matcher));
+        _functionMatchers = <_FunctionMatcher>[
+          ...?existing,
+          _FunctionMatcher<T>(description, feature, matcher)
+        ];
 
   @override
   TypeMatcher<T> having(
-          Object feature(T source), String description, Object matcher) =>
+          Object Function(T) feature, String description, Object matcher) =>
       HavingMatcher(_parent, description, feature, matcher, _functionMatchers);
 
   @override

lib/src/iterable_matchers.dart

@@ -237,8 +237,8 @@ class _UnorderedMatches extends _IterableMatcher {
 /// The [comparator] function, taking an expected and an actual argument, and
 /// returning whether they match, will be applied to each pair in order.
 /// [description] should be a meaningful name for the comparator.
-Matcher pairwiseCompare<S, T>(
-        Iterable<S> expected, bool comparator(S a, T b), String description) =>
+Matcher pairwiseCompare<S, T>(Iterable<S> expected,
+        bool Function(S, T) comparator, String description) =>
     _PairwiseCompare(expected, comparator, description);
 
 typedef _Comparator<S, T> = bool Function(S a, T b);
@@ -280,9 +280,9 @@ class _PairwiseCompare<S, T> extends _IterableMatcher {
     } else {
       return mismatchDescription
           .add('has ')
-          .addDescriptionOf(matchState["actual"])
+          .addDescriptionOf(matchState['actual'])
           .add(' which is not $_description ')
-          .addDescriptionOf(matchState["expected"])
+          .addDescriptionOf(matchState['expected'])
           .add(' at index ${matchState["index"]}');
     }
   }

lib/src/numeric_matchers.dart

@@ -83,7 +83,7 @@ class _InRange extends FeatureMatcher<num> {
 
   @override
   Description describe(Description description) =>
-      description.add("be in range from "
+      description.add('be in range from '
           "$_low (${_lowMatchValue ? 'inclusive' : 'exclusive'}) to "
           "$_high (${_highMatchValue ? 'inclusive' : 'exclusive'})");
 }

lib/src/pretty_print.dart

@@ -21,17 +21,17 @@ String prettyPrint(object, {int maxLineLength, int maxItems}) {
     if (object is Matcher) {
       var description = StringDescription();
       object.describe(description);
-      return "<$description>";
+      return '<$description>';
     }
 
     // Avoid looping infinitely on recursively-nested data structures.
-    if (seen.contains(object)) return "(recursive)";
+    if (seen.contains(object)) return '(recursive)';
     seen = seen.union({object});
     String pp(child) => _prettyPrint(child, indent + 2, seen, false);
 
     if (object is Iterable) {
       // Print the type name for non-List iterables.
-      var type = object is List ? "" : _typeName(object) + ":";
+      var type = object is List ? '' : _typeName(object) + ':';
 
       // Truncate the list of strings if it's longer than [maxItems].
       var strings = object.map(pp).toList();
@@ -44,18 +44,18 @@ String prettyPrint(object, {int maxLineLength, int maxItems}) {
       var singleLine = "$type[${strings.join(', ')}]";
       if ((maxLineLength == null ||
               singleLine.length + indent <= maxLineLength) &&
-          !singleLine.contains("\n")) {
+          !singleLine.contains('\n')) {
         return singleLine;
       }
 
       // Otherwise, print each member on its own line.
-      return "$type[\n" +
+      return '$type[\n' +
           strings.map((string) {
             return _indent(indent + 2) + string;
-          }).join(",\n") +
-          "\n" +
+          }).join(',\n') +
+          '\n' +
           _indent(indent) +
-          "]";
+          ']';
     } else if (object is Map) {
       // Convert the contents of the map to string representations.
       var strings = object.keys.map((key) {
@@ -69,34 +69,34 @@ String prettyPrint(object, {int maxLineLength, int maxItems}) {
 
       // If the printed string is short and doesn't contain a newline, print it
       // as a single line.
-      var singleLine = "{${strings.join(", ")}}";
+      var singleLine = '{${strings.join(", ")}}';
       if ((maxLineLength == null ||
               singleLine.length + indent <= maxLineLength) &&
-          !singleLine.contains("\n")) {
+          !singleLine.contains('\n')) {
         return singleLine;
       }
 
       // Otherwise, print each key/value pair on its own line.
-      return "{\n" +
+      return '{\n' +
           strings.map((string) {
             return _indent(indent + 2) + string;
-          }).join(",\n") +
-          "\n" +
+          }).join(',\n') +
+          '\n' +
           _indent(indent) +
-          "}";
+          '}';
     } else if (object is String) {
       // Escape strings and print each line on its own line.
-      var lines = object.split("\n");
+      var lines = object.split('\n');
       return "'" +
           lines.map(_escapeString).join("\\n'\n${_indent(indent + 2)}'") +
           "'";
     } else {
-      var value = object.toString().replaceAll("\n", _indent(indent) + "\n");
-      var defaultToString = value.startsWith("Instance of ");
+      var value = object.toString().replaceAll('\n', _indent(indent) + '\n');
+      var defaultToString = value.startsWith('Instance of ');
 
       // If this is the top-level call to [prettyPrint], wrap the value on angle
       // brackets to set it apart visually.
-      if (top) value = "<$value>";
+      if (top) value = '<$value>';
 
       // Print the type of objects with custom [toString] methods. Primitive
       // objects and objects that don't implement a custom [toString] don't need
@@ -111,7 +111,7 @@ String prettyPrint(object, {int maxLineLength, int maxItems}) {
           defaultToString) {
         return value;
       } else {
-        return "${_typeName(object)}:$value";
+        return '${_typeName(object)}:$value';
       }
     }
   }
@@ -124,10 +124,10 @@ String _indent(int length) => List.filled(length, ' ').join('');
 /// Returns the name of the type of [x] with fallbacks for core types with
 /// private implementations.
 String _typeName(x) {
-  if (x is Type) return "Type";
-  if (x is Uri) return "Uri";
-  if (x is Set) return "Set";
-  if (x is BigInt) return "BigInt";
+  if (x is Type) return 'Type';
+  if (x is Uri) return 'Uri';
+  if (x is Set) return 'Set';
+  if (x is BigInt) return 'BigInt';
   return '${x.runtimeType}';
 }
 

lib/src/string_matchers.dart

@@ -47,12 +47,10 @@ Matcher equalsIgnoringWhitespace(String value) =>
     _IsEqualIgnoringWhitespace(value);
 
 class _IsEqualIgnoringWhitespace extends FeatureMatcher<String> {
-  final String _value;
   final String _matchValue;
 
   _IsEqualIgnoringWhitespace(String value)
-      : _value = value,
-        _matchValue = collapseWhitespace(value);
+      : _matchValue = collapseWhitespace(value);
 
   @override
   bool typedMatches(String item, Map matchState) =>

lib/src/type_matcher.dart

@@ -80,7 +80,7 @@ class TypeMatcher<T> extends Matcher {
   ///    .having((e) => e.end, 'end', isNull);
   /// ```
   TypeMatcher<T> having(
-          Object feature(T source), String description, Object matcher) =>
+          Object Function(T) feature, String description, Object matcher) =>
       HavingMatcher(this, description, feature, matcher);
 
   @override

lib/src/util.dart

@@ -21,7 +21,7 @@ const _escapeMap = {
 
 /// A [RegExp] that matches whitespace characters that should be escaped.
 final _escapeRegExp = RegExp(
-    "[\\x00-\\x07\\x0E-\\x1F${_escapeMap.keys.map(_getHexLiteral).join()}]");
+    '[\\x00-\\x07\\x0E-\\x1F${_escapeMap.keys.map(_getHexLiteral).join()}]');
 
 /// Useful utility for nesting match states.
 void addStateInfo(Map matchState, Map values) {

pubspec.yaml

@@ -1,14 +1,13 @@
 name: matcher
-version: 0.12.6
+version: 0.12.7-dev
 
 description: >-
   Support for specifying test expectations via an extensible Matcher class.
   Also includes a number of built-in Matcher implementations for common cases.
-author: Dart Team <misc@dartlang.org>
 homepage: https://github.com/dart-lang/matcher
 
 environment:
-  sdk: '>=2.2.0 <3.0.0'
+  sdk: '>=2.3.0 <3.0.0'
 
 dependencies:
   stack_trace: ^1.2.0