From f29aba42d2abeda6419488139da77a4ab63314ce Mon Sep 17 00:00:00 2001
From: Michael Miller <icy.arctic.fox@gmail.com>
Date: Wed, 6 Mar 2019 13:04:18 -0700
Subject: [PATCH] Update TruthyMatcher to use MatchData

---
 spec/matchers/truthy_matcher_spec.cr     | 380 ++++++++++++++++-------
 src/spectator/matchers/truthy_matcher.cr |  56 +++-
 2 files changed, 300 insertions(+), 136 deletions(-)

diff --git a/spec/matchers/truthy_matcher_spec.cr b/spec/matchers/truthy_matcher_spec.cr
index cf4c5a9..70207a8 100644
--- a/spec/matchers/truthy_matcher_spec.cr
+++ b/spec/matchers/truthy_matcher_spec.cr
@@ -16,137 +16,279 @@ def be_comparison
 end
 
 describe Spectator::Matchers::TruthyMatcher do
-  context "truthy" do
-    describe "#match?" do
-      context "with a truthy value" do
-        it "is true" do
-          value = 42
-          partial = new_partial(value)
-          matcher = Spectator::Matchers::TruthyMatcher.new(true)
-          matcher.match?(partial).should be_true
+  describe "#match" do
+    context "returned MatchData" do
+      context "truthy" do
+        describe "#matched?" do
+          context "with a truthy value" do
+            it "is true" do
+              value = 42
+              partial = new_partial(value)
+              matcher = Spectator::Matchers::TruthyMatcher.new(true)
+              match_data = matcher.match(partial)
+              match_data.matched?.should be_true
+            end
+          end
+
+          context "with false" do
+            it "is false" do
+              value = false
+              partial = new_partial(value)
+              matcher = Spectator::Matchers::TruthyMatcher.new(true)
+              match_data = matcher.match(partial)
+              match_data.matched?.should be_false
+            end
+          end
+
+          context "with nil" do
+            it "is false" do
+              value = nil
+              partial = new_partial(value)
+              matcher = Spectator::Matchers::TruthyMatcher.new(true)
+              match_data = matcher.match(partial)
+              match_data.matched?.should be_false
+            end
+          end
+        end
+
+        describe "#values" do
+          context "expected" do
+            it "contains the definition of falsey" do
+              value = 42
+              partial = new_partial(value)
+              matcher = Spectator::Matchers::TruthyMatcher.new(true)
+              match_data = matcher.match(partial)
+              match_data.values[:expected].should match(/false or nil/i)
+            end
+
+            it "is prefixed with \"Not\"" do
+              value = 42
+              partial = new_partial(value)
+              matcher = Spectator::Matchers::TruthyMatcher.new(true)
+              match_data = matcher.match(partial)
+              match_data.values[:expected].should start_with(/not/i)
+            end
+          end
+
+          context "actual" do
+            it "is the actual value" do
+              value = 42
+              partial = new_partial(value)
+              matcher = Spectator::Matchers::TruthyMatcher.new(true)
+              match_data = matcher.match(partial)
+              match_data.values[:actual].should eq(value)
+            end
+          end
+
+          context "truthy" do
+            context "when the actual value is truthy" do
+              it "is true" do
+                value = 42
+                partial = new_partial(value)
+                matcher = Spectator::Matchers::TruthyMatcher.new(true)
+                match_data = matcher.match(partial)
+                match_data.values[:truthy].should be_true
+              end
+            end
+
+            context "when the actual value is false" do
+              it "is false" do
+                value = false
+                partial = new_partial(value)
+                matcher = Spectator::Matchers::TruthyMatcher.new(true)
+                match_data = matcher.match(partial)
+                match_data.values[:truthy].should be_false
+              end
+            end
+
+            context "when the actual value is nil" do
+              it "is false" do
+                value = nil
+                partial = new_partial(value)
+                matcher = Spectator::Matchers::TruthyMatcher.new(true)
+                match_data = matcher.match(partial)
+                match_data.values[:truthy].should be_false
+              end
+            end
+          end
+        end
+
+        describe "#message" do
+          it "contains the actual label" do
+            value = 42
+            label = "everything"
+            partial = new_partial(value, label)
+            matcher = Spectator::Matchers::TruthyMatcher.new(true)
+            match_data = matcher.match(partial)
+            match_data.message.should contain(label)
+          end
+
+          it "contains the \"truthy\"" do
+            value = 42
+            label = "everything"
+            partial = new_partial(value)
+            matcher = Spectator::Matchers::TruthyMatcher.new(true)
+            match_data = matcher.match(partial)
+            match_data.message.should contain("truthy")
+          end
+        end
+
+        describe "#negated_message" do
+          it "contains the actual label" do
+            value = 42
+            label = "everything"
+            partial = new_partial(value, label)
+            matcher = Spectator::Matchers::TruthyMatcher.new(true)
+            match_data = matcher.match(partial)
+            match_data.negated_message.should contain(label)
+          end
+
+          it "contains the \"truthy\"" do
+            value = 42
+            label = "everything"
+            partial = new_partial(value)
+            matcher = Spectator::Matchers::TruthyMatcher.new(true)
+            match_data = matcher.match(partial)
+            match_data.negated_message.should contain("truthy")
+          end
         end
       end
 
-      context "with false" do
-        it "is false" do
-          value = false
-          partial = new_partial(value)
-          matcher = Spectator::Matchers::TruthyMatcher.new(true)
-          matcher.match?(partial).should be_false
+      context "falsey" do
+        describe "#matched?" do
+          context "with a truthy value" do
+            it "is false" do
+              value = 42
+              partial = new_partial(value)
+              matcher = Spectator::Matchers::TruthyMatcher.new(false)
+              match_data = matcher.match(partial)
+              match_data.matched?.should be_false
+            end
+          end
+
+          context "with false" do
+            it "is true" do
+              value = false
+              partial = new_partial(value)
+              matcher = Spectator::Matchers::TruthyMatcher.new(false)
+              match_data = matcher.match(partial)
+              match_data.matched?.should be_true
+            end
+          end
+
+          context "with nil" do
+            it "is true" do
+              value = nil
+              partial = new_partial(value)
+              matcher = Spectator::Matchers::TruthyMatcher.new(false)
+              match_data = matcher.match(partial)
+              match_data.matched?.should be_true
+            end
+          end
         end
-      end
 
-      context "with nil" do
-        it "is false" do
-          value = nil
-          partial = new_partial(value)
-          matcher = Spectator::Matchers::TruthyMatcher.new(true)
-          matcher.match?(partial).should be_false
+        describe "#values" do
+          context "expected" do
+            it "contains the definition of falsey" do
+              value = 42
+              partial = new_partial(value)
+              matcher = Spectator::Matchers::TruthyMatcher.new(false)
+              match_data = matcher.match(partial)
+              match_data.values[:expected].should match(/false or nil/i)
+            end
+
+            it "is not prefixed with \"Not\"" do
+              value = 42
+              partial = new_partial(value)
+              matcher = Spectator::Matchers::TruthyMatcher.new(false)
+              match_data = matcher.match(partial)
+              match_data.values[:expected].should_not start_with(/not/i)
+            end
+          end
+
+          context "actual" do
+            it "is the actual value" do
+              value = 42
+              partial = new_partial(value)
+              matcher = Spectator::Matchers::TruthyMatcher.new(false)
+              match_data = matcher.match(partial)
+              match_data.values[:actual].should eq(value)
+            end
+          end
+
+          context "truthy" do
+            context "when the actual value is truthy" do
+              it "is true" do
+                value = 42
+                partial = new_partial(value)
+                matcher = Spectator::Matchers::TruthyMatcher.new(false)
+                match_data = matcher.match(partial)
+                match_data.values[:truthy].should be_true
+              end
+            end
+
+            context "when the actual value is false" do
+              it "is false" do
+                value = false
+                partial = new_partial(value)
+                matcher = Spectator::Matchers::TruthyMatcher.new(false)
+                match_data = matcher.match(partial)
+                match_data.values[:truthy].should be_false
+              end
+            end
+
+            context "when the actual value is nil" do
+              it "is false" do
+                value = nil
+                partial = new_partial(value)
+                matcher = Spectator::Matchers::TruthyMatcher.new(false)
+                match_data = matcher.match(partial)
+                match_data.values[:truthy].should be_false
+              end
+            end
+          end
         end
-      end
-    end
 
-    describe "#message" do
-      it "contains the actual label" do
-        value = 42
-        label = "everything"
-        partial = new_partial(value, label)
-        matcher = Spectator::Matchers::TruthyMatcher.new(true)
-        matcher.message(partial).should contain(label)
-      end
+        describe "#message" do
+          it "contains the actual label" do
+            value = 42
+            label = "everything"
+            partial = new_partial(value, label)
+            matcher = Spectator::Matchers::TruthyMatcher.new(false)
+            match_data = matcher.match(partial)
+            match_data.message.should contain(label)
+          end
 
-      it "contains the \"truthy\"" do
-        value = 42
-        label = "everything"
-        partial = new_partial(value)
-        matcher = Spectator::Matchers::TruthyMatcher.new(true)
-        matcher.message(partial).should contain("truthy")
-      end
-    end
-
-    describe "#negated_message" do
-      it "contains the actual label" do
-        value = 42
-        label = "everything"
-        partial = new_partial(value, label)
-        matcher = Spectator::Matchers::TruthyMatcher.new(true)
-        matcher.negated_message(partial).should contain(label)
-      end
-
-      it "contains the \"truthy\"" do
-        value = 42
-        label = "everything"
-        partial = new_partial(value)
-        matcher = Spectator::Matchers::TruthyMatcher.new(true)
-        matcher.negated_message(partial).should contain("truthy")
-      end
-    end
-  end
-
-  context "falsey" do
-    describe "#match?" do
-      context "with a truthy value" do
-        it "is false" do
-          value = 42
-          partial = new_partial(value)
-          matcher = Spectator::Matchers::TruthyMatcher.new(false)
-          matcher.match?(partial).should be_false
+          it "contains the \"falsey\"" do
+            value = 42
+            label = "everything"
+            partial = new_partial(value)
+            matcher = Spectator::Matchers::TruthyMatcher.new(false)
+            match_data = matcher.match(partial)
+            match_data.message.should contain("falsey")
+          end
         end
-      end
 
-      context "with false" do
-        it "is true" do
-          value = false
-          partial = new_partial(value)
-          matcher = Spectator::Matchers::TruthyMatcher.new(false)
-          matcher.match?(partial).should be_true
+        describe "#negated_message" do
+          it "contains the actual label" do
+            value = 42
+            label = "everything"
+            partial = new_partial(value, label)
+            matcher = Spectator::Matchers::TruthyMatcher.new(false)
+            match_data = matcher.match(partial)
+            match_data.negated_message.should contain(label)
+          end
+
+          it "contains the \"falsey\"" do
+            value = 42
+            label = "everything"
+            partial = new_partial(value)
+            matcher = Spectator::Matchers::TruthyMatcher.new(false)
+            match_data = matcher.match(partial)
+            match_data.negated_message.should contain("falsey")
+          end
         end
       end
-
-      context "with nil" do
-        it "is true" do
-          value = nil
-          partial = new_partial(value)
-          matcher = Spectator::Matchers::TruthyMatcher.new(false)
-          matcher.match?(partial).should be_true
-        end
-      end
-    end
-
-    describe "#message" do
-      it "contains the actual label" do
-        value = 42
-        label = "everything"
-        partial = new_partial(value, label)
-        matcher = Spectator::Matchers::TruthyMatcher.new(false)
-        matcher.message(partial).should contain(label)
-      end
-
-      it "contains the \"falsey\"" do
-        value = 42
-        label = "everything"
-        partial = new_partial(value)
-        matcher = Spectator::Matchers::TruthyMatcher.new(false)
-        matcher.message(partial).should contain("falsey")
-      end
-    end
-
-    describe "#negated_message" do
-      it "contains the actual label" do
-        value = 42
-        label = "everything"
-        partial = new_partial(value, label)
-        matcher = Spectator::Matchers::TruthyMatcher.new(false)
-        matcher.negated_message(partial).should contain(label)
-      end
-
-      it "contains the \"falsey\"" do
-        value = 42
-        label = "everything"
-        partial = new_partial(value)
-        matcher = Spectator::Matchers::TruthyMatcher.new(false)
-        matcher.negated_message(partial).should contain("falsey")
-      end
     end
   end
 
diff --git a/src/spectator/matchers/truthy_matcher.cr b/src/spectator/matchers/truthy_matcher.cr
index 3975416..81f3449 100644
--- a/src/spectator/matchers/truthy_matcher.cr
+++ b/src/spectator/matchers/truthy_matcher.cr
@@ -21,28 +21,16 @@ 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)
+    private def match?(actual)
       # Cast value to truthy value and compare.
-      @truthy == !!partial.actual
+      @truthy == !!actual
     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")
-    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}"
-    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}"
+    def match(partial)
+      actual = partial.actual
+      MatchData.new(match?(actual), @truthy, actual, partial.label)
     end
 
     # Creates a matcher that checks if a value is less than an expected value.
@@ -98,5 +86,39 @@ module Spectator::Matchers
     def !=(expected : ExpectedType) forall ExpectedType
       InequalityMatcher.new(expected)
     end
+
+    # Match data specific to this matcher.
+    private struct MatchData(ActualType) < MatchData
+      # Creates the match data.
+      def initialize(matched, @truthy : Bool, @actual : ActualType, @actual_label : String)
+        super(matched)
+      end
+
+      # Information about the match.
+      def values
+        {
+          expected: @truthy ? "Not false or nil" : "false or nil",
+          actual:   @actual,
+          truthy:   !!@actual,
+        }
+      end
+
+      # Describes the condition that satisfies the matcher.
+      # This is informational and displayed to the end-user.
+      def message
+        "#{@actual_label} is #{expected_label}"
+      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 #{expected_label}"
+      end
+
+      # Textual representation of what the matcher expects.
+      private def expected_label
+        @truthy ? "truthy" : "falsey"
+      end
+    end
   end
 end