fix(built_value_test): respect non comparable fields

Signed-off-by: Nikolas Rimikis <leptopoda@users.noreply.github.com>

Author: Leptopoda

built_value_test/lib/matcher.dart

@@ -9,8 +9,12 @@ import 'package:matcher/matcher.dart';
 /// Returns a matcher that matches if the value is structurally equal to
 /// [expected].
 ///
+/// When [onlyCheckComparable] fields that are not comparable are ignored for
+/// the equality check.
+///
 /// Improves on a simple equality test by offering a detailed mismatch message.
-Matcher equalsBuilt(Built expected) => _BuiltValueMatcher(expected);
+Matcher equalsBuilt(Built expected, {bool onlyCheckComparable = false}) =>
+    _BuiltValueMatcher(expected, onlyCheckComparable);
 
 /// Matcher for [Built] instances.
 ///
@@ -19,8 +23,10 @@ Matcher equalsBuilt(Built expected) => _BuiltValueMatcher(expected);
 class _BuiltValueMatcher implements Matcher {
   final Built _expected;
   final Matcher _delegate;
+  final bool _onlyCheckComparable;
 
-  _BuiltValueMatcher(this._expected) : _delegate = equals(_toMap(_expected));
+  _BuiltValueMatcher(this._expected, this._onlyCheckComparable)
+      : _delegate = equals(_toMap(_expected));
 
   @override
   Description describe(Description description) =>
@@ -41,6 +47,8 @@ class _BuiltValueMatcher implements Matcher {
   bool matches(dynamic item, Map matchState) {
     if (_expected.runtimeType != item.runtimeType) return false;
 
+    if (_onlyCheckComparable && _expected == item) return true;
+
     return _delegate.matches(_toMap(item), matchState);
   }
 }

built_value_test/test/matcher_test.dart

@@ -103,7 +103,14 @@ void main() {
         ..name = 'foo'
         ..onChanged = () => 'Change happened!');
 
-      expect(value, otherValue);
+      expect(value, isNot(equalsBuilt(otherValue)));
+      expect(
+        value,
+        equalsBuilt(
+          otherValue,
+          onlyCheckComparable: true,
+        ),
+      );
     });
 
     test('compared value matcher with different onChanged outcomes', () {
@@ -114,7 +121,14 @@ void main() {
         ..name = 'foo'
         ..onChanged = () => 'Change did not happen!');
 
-      expect(value, otherValue);
+      expect(value, isNot(equalsBuilt(otherValue)));
+      expect(
+        value,
+        equalsBuilt(
+          otherValue,
+          onlyCheckComparable: true,
+        ),
+      );
     });
 
     test('compared value matcher with different names', () {