Use literal calls for equal?, == and !=

* This avoids bugs like https://bugs.ruby-lang.org/issues/18671
* Might also make these common matchers slightly faster

Author: eregon

spec/mspec/lib/mspec/expectations/expectations.rb

@@ -32,4 +32,8 @@ def self.fail_predicate(receiver, predicate, args, block, result, expectation)
     result_to_s = MSpec.format(result)
     raise SpecExpectationNotMetError, "Expected #{receiver_to_s}#{predicate_to_s}#{args_to_s}\n#{expectation} but was #{result_to_s}"
   end
+
+  def self.fail_single_arg_predicate(receiver, predicate, arg, result, expectation)
+    fail_predicate(receiver, predicate, [arg], nil, result, expectation)
+  end
 end

spec/mspec/lib/mspec/matchers/base.rb

@@ -16,15 +16,24 @@ def initialize(actual)
   end
 
   def ==(expected)
-    method_missing(:==, expected)
+    result = @actual == expected
+    unless result
+      ::SpecExpectation.fail_single_arg_predicate(@actual, :==, expected, result, "to be truthy")
+    end
   end
 
   def !=(expected)
-    method_missing(:!=, expected)
+    result = @actual != expected
+    unless result
+      ::SpecExpectation.fail_single_arg_predicate(@actual, :!=, expected, result, "to be truthy")
+    end
   end
 
   def equal?(expected)
-    method_missing(:equal?, expected)
+    result = @actual.equal?(expected)
+    unless result
+      ::SpecExpectation.fail_single_arg_predicate(@actual, :equal?, expected, result, "to be truthy")
+    end
   end
 
   def method_missing(name, *args, &block)
@@ -41,15 +50,24 @@ def initialize(actual)
   end
 
   def ==(expected)
-    method_missing(:==, expected)
+    result = @actual == expected
+    if result
+      ::SpecExpectation.fail_single_arg_predicate(@actual, :==, expected, result, "to be falsy")
+    end
   end
 
   def !=(expected)
-    method_missing(:!=, expected)
+    result = @actual != expected
+    if result
+      ::SpecExpectation.fail_single_arg_predicate(@actual, :!=, expected, result, "to be falsy")
+    end
   end
 
   def equal?(expected)
-    method_missing(:equal?, expected)
+    result = @actual.equal?(expected)
+    if result
+      ::SpecExpectation.fail_single_arg_predicate(@actual, :equal?, expected, result, "to be falsy")
+    end
   end
 
   def method_missing(name, *args, &block)