Update HaveValueMatcher to use MatchData

spec/matchers/have_value_matcher_spec.cr

@@ -1,14 +1,23 @@
 require "../spec_helper"
 
+private struct FakeValueSet
+  def has_value?(value)
+    true
+  end
+end
+
 describe Spectator::Matchers::HaveValueMatcher do
-  describe "#match?" do
+  describe "#match" do
+    context "returned MatchData" do
+      describe "#matched?" do
         context "with an existing value" do
           it "is true" do
             hash = Hash{"foo" => "bar"}
             value = "bar"
             partial = new_partial(hash)
             matcher = Spectator::Matchers::HaveValueMatcher.new(value)
-        matcher.match?(partial).should be_true
+            match_data = matcher.match(partial)
+            match_data.matched?.should be_true
           end
         end
 
@@ -18,7 +27,45 @@ describe Spectator::Matchers::HaveValueMatcher do
             value = "baz"
             partial = new_partial(hash)
             matcher = Spectator::Matchers::HaveValueMatcher.new(value)
-        matcher.match?(partial).should be_false
+            match_data = matcher.match(partial)
+            match_data.matched?.should be_false
+          end
+        end
+      end
+
+      describe "#values" do
+        context "value" do
+          it "is the expected value" do
+            hash = {"foo" => "bar"}
+            value = "baz"
+            partial = new_partial(hash)
+            matcher = Spectator::Matchers::HaveValueMatcher.new(value)
+            match_data = matcher.match(partial)
+            match_data.values[:value].should eq(value)
+          end
+        end
+
+        context "actual" do
+          context "when #values is available" do
+            it "is the list of values" do
+              hash = Hash{"foo" => "bar"}
+              value = "baz"
+              partial = new_partial(hash)
+              matcher = Spectator::Matchers::HaveValueMatcher.new(value)
+              match_data = matcher.match(partial)
+              match_data.values[:actual].should eq(hash.values)
+            end
+          end
+
+          context "when #values isn't available" do
+            it "is the actual value" do
+              actual = FakeValueSet.new
+              value = "baz"
+              partial = new_partial(actual)
+              matcher = Spectator::Matchers::HaveValueMatcher.new(value)
+              match_data = matcher.match(partial)
+              match_data.values[:actual].should eq(actual)
+            end
           end
         end
       end
@@ -30,7 +77,8 @@ describe Spectator::Matchers::HaveValueMatcher do
           label = "blah"
           partial = new_partial(hash, label)
           matcher = Spectator::Matchers::HaveValueMatcher.new(value)
-      matcher.message(partial).should contain(label)
+          match_data = matcher.match(partial)
+          match_data.message.should contain(label)
         end
 
         it "contains the expected label" do
@@ -39,7 +87,8 @@ describe Spectator::Matchers::HaveValueMatcher do
           label = "blah"
           partial = new_partial(hash)
           matcher = Spectator::Matchers::HaveValueMatcher.new(value, label)
-      matcher.message(partial).should contain(label)
+          match_data = matcher.match(partial)
+          match_data.message.should contain(label)
         end
 
         context "when the expected label is omitted" do
@@ -48,7 +97,8 @@ describe Spectator::Matchers::HaveValueMatcher do
             value = "bar"
             partial = new_partial(hash)
             matcher = Spectator::Matchers::HaveValueMatcher.new(value)
-        matcher.message(partial).should contain(value.to_s)
+            match_data = matcher.match(partial)
+            match_data.message.should contain(value.to_s)
           end
         end
       end
@@ -60,7 +110,8 @@ describe Spectator::Matchers::HaveValueMatcher do
           label = "blah"
           partial = new_partial(hash, label)
           matcher = Spectator::Matchers::HaveValueMatcher.new(value)
-      matcher.negated_message(partial).should contain(label)
+          match_data = matcher.match(partial)
+          match_data.negated_message.should contain(label)
         end
 
         it "contains the expected label" do
@@ -69,7 +120,8 @@ describe Spectator::Matchers::HaveValueMatcher do
           label = "blah"
           partial = new_partial(hash)
           matcher = Spectator::Matchers::HaveValueMatcher.new(value, label)
-      matcher.negated_message(partial).should contain(label)
+          match_data = matcher.match(partial)
+          match_data.negated_message.should contain(label)
         end
 
         context "when the expected label is omitted" do
@@ -78,7 +130,10 @@ describe Spectator::Matchers::HaveValueMatcher do
             value = "bar"
             partial = new_partial(hash)
             matcher = Spectator::Matchers::HaveValueMatcher.new(value)
-        matcher.negated_message(partial).should contain(value.to_s)
+            match_data = matcher.match(partial)
+            match_data.negated_message.should contain(value.to_s)
+          end
+        end
       end
     end
   end

src/spectator/matchers/have_value_matcher.cr

@@ -5,27 +5,44 @@ module Spectator::Matchers
   # The set is checked with the `has_value?` method.
   struct HaveValueMatcher(ExpectedType) < ValueMatcher(ExpectedType)
     # Determines whether the matcher is satisfied with the value given to it.
-    # True is returned if the match was successful, false otherwise.
-    def match?(partial)
-      partial.actual.has_value?(expected)
+    private def match?(actual)
+      actual.has_value?(expected)
     end
 
     # Determines whether the matcher is satisfied with the partial given to it.
     # `MatchData` is returned that contains information about the match.
-    def match(partial) : MatchData
-      raise NotImplementedError.new("#match")
+    def match(partial)
+      values = ExpectedActual.new(partial, self)
+      MatchData.new(match?(values.actual), values)
+    end
+
+    # Match data specific to this matcher.
+    private struct MatchData(ExpectedType, ActualType) < MatchData
+      # Creates the match data.
+      def initialize(matched, @values : ExpectedActual(ExpectedType, ActualType))
+        super(matched)
+      end
+
+      # Information about the match.
+      def values
+        actual = @values.actual
+        {
+          value:  @values.expected,
+          actual: actual.responds_to?(:values) ? actual.values : actual,
+        }
       end
 
       # Describes the condition that satisfies the matcher.
       # This is informational and displayed to the end-user.
-    def message(partial)
-      "Expected #{partial.label} to have value #{label}"
+      def message
+        "#{@values.actual_label} has value #{@values.expected_label}"
       end
 
       # Describes the condition that won't satsify the matcher.
       # This is informational and displayed to the end-user.
-    def negated_message(partial)
-      "Expected #{partial.label} to not have value #{label}"
+      def negated_message
+        "#{@values.actual_label} does not have value #{@values.expected_label}"
+      end
     end
   end
 end