Update PredicateMatcher to use MatchData

spec/matchers/predicate_matcher_spec.cr

@@ -1,57 +1,89 @@
 require "../spec_helper"
 
 describe Spectator::Matchers::PredicateMatcher do
-  describe "#match?" do
-    context "with a true predicate" do
-      it "is true" do
-        value = "foobar"
-        partial = new_partial(value)
-        matcher = Spectator::Matchers::PredicateMatcher(NamedTuple(ascii_only: Nil)).new
-        matcher.match?(partial).should be_true
+  describe "#match" do
+    context "returned MatchData" do
+      describe "#match?" do
+        context "with a true predicate" do
+          it "is true" do
+            value = "foobar"
+            partial = new_partial(value)
+            matcher = Spectator::Matchers::PredicateMatcher(NamedTuple(ascii_only: Nil)).new
+            match_data = matcher.match(partial)
+            match_data.matched?.should be_true
+          end
+        end
+
+        context "with a false predicate" do
+          it "is false" do
+            value = "foobar"
+            partial = new_partial(value)
+            matcher = Spectator::Matchers::PredicateMatcher(NamedTuple(empty: Nil)).new
+            match_data = matcher.match(partial)
+            match_data.matched?.should be_false
+          end
+        end
       end
-    end
 
-    context "with a false predicate" do
-      it "is false" do
-        value = "foobar"
-        partial = new_partial(value)
-        matcher = Spectator::Matchers::PredicateMatcher(NamedTuple(empty: Nil)).new
-        matcher.match?(partial).should be_false
+      describe "#values" do
+        it "contains a key for each expected attribute" do
+          value = "foobar"
+          partial = new_partial(value)
+          matcher = Spectator::Matchers::PredicateMatcher(NamedTuple(empty: Nil, ascii_only: Nil)).new
+          match_data = matcher.match(partial)
+          values = match_data.values
+          values.has_key?(:empty).should be_true
+          values.has_key?(:ascii_only).should be_true
+        end
+
+        it "has the actual values" do
+          value = "foobar"
+          partial = new_partial(value)
+          matcher = Spectator::Matchers::PredicateMatcher(NamedTuple(empty: Nil, ascii_only: Nil)).new
+          match_data = matcher.match(partial)
+          values = match_data.values
+          values.[:empty].should eq(value.empty?)
+          values.[:ascii_only].should eq(value.ascii_only?)
+        end
       end
-    end
-  end
 
-  describe "#message" do
-    it "contains the actual label" do
-      value = "foobar"
-      label = "blah"
-      partial = new_partial(value, label)
-      matcher = Spectator::Matchers::PredicateMatcher(NamedTuple(ascii_only: Nil)).new
-      matcher.message(partial).should contain(label)
-    end
+      describe "#message" do
+        it "contains the actual label" do
+          value = "foobar"
+          label = "blah"
+          partial = new_partial(value, label)
+          matcher = Spectator::Matchers::PredicateMatcher(NamedTuple(ascii_only: Nil)).new
+          match_data = matcher.match(partial)
+          match_data.message.should contain(label)
+        end
 
-    it "contains stringified form of predicate" do
-      value = "foobar"
-      partial = new_partial(value)
-      matcher = Spectator::Matchers::PredicateMatcher(NamedTuple(ascii_only: Nil)).new
-      matcher.message(partial).should contain("ascii_only")
-    end
-  end
+        it "contains stringified form of predicate" do
+          value = "foobar"
+          partial = new_partial(value)
+          matcher = Spectator::Matchers::PredicateMatcher(NamedTuple(ascii_only: Nil)).new
+          match_data = matcher.match(partial)
+          match_data.message.should contain("ascii_only")
+        end
+      end
 
-  describe "#negated_message" do
-    it "contains the actual label" do
-      value = "foobar"
-      label = "blah"
-      partial = new_partial(value, label)
-      matcher = Spectator::Matchers::PredicateMatcher(NamedTuple(ascii_only: Nil)).new
-      matcher.negated_message(partial).should contain(label)
-    end
+      describe "#negated_message" do
+        it "contains the actual label" do
+          value = "foobar"
+          label = "blah"
+          partial = new_partial(value, label)
+          matcher = Spectator::Matchers::PredicateMatcher(NamedTuple(ascii_only: Nil)).new
+          match_data = matcher.match(partial)
+          match_data.negated_message.should contain(label)
+        end
 
-    it "contains stringified form of predicate" do
-      value = "foobar"
-      partial = new_partial(value)
-      matcher = Spectator::Matchers::PredicateMatcher(NamedTuple(ascii_only: Nil)).new
-      matcher.negated_message(partial).should contain("ascii_only")
+        it "contains stringified form of predicate" do
+          value = "foobar"
+          partial = new_partial(value)
+          matcher = Spectator::Matchers::PredicateMatcher(NamedTuple(ascii_only: Nil)).new
+          match_data = matcher.match(partial)
+          match_data.negated_message.should contain("ascii_only")
+        end
+      end
     end
   end
 end

src/spectator/matchers/predicate_matcher.cr

@@ -12,13 +12,10 @@ module Spectator::Matchers
     end
 
     # 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)
-      actual = partial.actual
-
+    private def match?(values)
       # Test each predicate and immediately return false if one is false.
       {% for attribute in ExpectedType.keys %}
-      return false unless actual.{{attribute}}?
+      return false unless values[{{attribute.symbolize}}]
       {% end %}
 
       # All checks passed if this point is reached.
@@ -28,19 +25,44 @@ module Spectator::Matchers
     # 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")
+      values = snapshot_values(partial.actual)
+      MatchData.new(match?(values), values, partial.label)
     end
 
-    # Describes the condition that satisfies the matcher.
-    # This is informational and displayed to the end-user.
-    def message(partial)
-      "Expected #{partial.label} to be #{label}"
+    # Captures all of the actual values.
+    # A `NamedTuple` is returned,
+    # with each key being the attribute.
+    private def snapshot_values(actual)
+      {% begin %}
+      {
+        {% for attribute in ExpectedType.keys %}
+        {{attribute}}: actual.{{attribute}}?,
+        {% end %}
+      }
+      {% end %}
     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 be #{label}"
+    # Match data specific to this matcher.
+    private struct MatchData(ActualType) < MatchData
+      # Creates the match data.
+      def initialize(matched, @values : ActualType, @actual_label : String)
+        super(matched)
+      end
+
+      # Information about the match.
+      getter values
+
+      # Describes the condition that satisfies the matcher.
+      # This is informational and displayed to the end-user.
+      def message
+        "#{@actual_label} is " + {{ActualType.keys.splat.stringify}}
+      end
+
+      # Describes the condition that won't satsify the matcher.
+      # This is informational and displayed to the end-user.
+      def negated_message
+        "#{@actual_label} is not " + {{ActualType.keys.splat.stringify}}
+      end
     end
   end
 end