Fixup more specs

Author: aardvark179

spec/tags/core/enumerable/sort_by_tags.txt

@@ -1,4 +1,2 @@
 fails:Hash#merge accepts multiple hashes
 fails:Hash#merge accepts zero arguments and returns self
-fails:Hash#merge! accepts multiple hashes
-fails:Hash#merge! accepts zero arguments

spec/tags/core/hash/fetch_tags.txt

@@ -27,6 +27,8 @@ empty?
 eql?
 fetch
 fetch_values
+filter
+filter!
 flatten
 has_key?
 has_value?

spec/tags/core/hash/fetch_values_tags.txt

@@ -576,3 +576,6 @@ def reset
 
 class Enumerator::ArithmeticSequence < Enumerator
 end
+
+class Enumerator::Chain < Enumerator
+end

spec/tags/core/hash/filter_tags.txt

@@ -417,6 +417,15 @@ def initialize(*args)
 end
 
 class KeyError < IndexError
+
+  attr_reader :receiver
+  attr_reader :key
+
+  def initialize(message = nil, receiver: nil, key: nil)
+    @receiver = receiver
+    @key = key
+    super(message)
+  end
 end
 
 class SignalException < Exception

spec/tags/core/hash/merge_tags.txt

@@ -219,7 +219,7 @@ def fetch(key, default=undefined)
     end
 
     return default unless undefined.equal?(default)
-    raise KeyError, "key #{key} not found"
+    raise KeyError.new("key #{key} not found", :receiver => self, :key => key)
   end
 
   def fetch_values(*keys, &block)
@@ -242,23 +242,25 @@ def keep_if
     self
   end
 
-  def merge!(other)
+  def merge!(*others)
     Truffle.check_frozen
 
-    other = Truffle::Type.coerce_to other, Hash, :to_hash
+    others.each do |other|
+      other = Truffle::Type.coerce_to other, Hash, :to_hash
 
-    if block_given?
-      other.each_pair do |key,value|
-        if key? key
-          __store__ key, yield(key, self[key], value)
-        else
+      if block_given?
+        other.each_pair do |key,value|
+          if key? key
+            __store__ key, yield(key, self[key], value)
+          else
+            __store__ key, value
+          end
+        end
+      else
+        other.each_pair do |key,value|
           __store__ key, value
         end
       end
-    else
-      other.each_pair do |key,value|
-        __store__ key, value
-      end
     end
     self
   end
@@ -283,6 +285,8 @@ def select
     selected
   end
 
+  alias_method :filter, :select
+
   def select!
     return to_enum(:select!) { size } unless block_given?
 
@@ -297,6 +301,8 @@ def select!
     self
   end
 
+  alias_method :filter!, :select!
+
   def to_h
     if block_given?
       super