Add boolean methods to outputs (#59)

.rubocop.yml

@@ -70,3 +70,6 @@ Style/StringLiterals:
 
 Style/TrailingCommaInArguments:
   EnforcedStyleForMultiline: comma
+
+Style/DoubleNegation:
+  Enabled: false

CHANGELOG.md

@@ -5,6 +5,9 @@ project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## unreleased
 
+Features:
+- Automatically generate "*?" methods for boolean comparison.
+
 ## v3.1.3
 
 Fixes:

README.md

@@ -115,6 +115,19 @@ result = BuildGreeting.call
 result.greeting # => "Have a wonderful day!"
 ```
 
+For each output a method is generated ending with a `?`, which is useful when the output is used for 
+conditional control flow, like if-else statements.
+
+```rb
+if result.greeting?
+  puts "Greetings is a non empty value"
+else
+  puts "Greetings is empty"
+end
+```
+
+The generated method will return the truthy or falsey values of variables.
+
 ### Defaults
 
 Inputs can be marked as optional by providing a default:

lib/service_actor/result.rb

@@ -51,5 +51,28 @@ def [](name)
     def display
       to_h.fetch(:display)
     end
+
+    private
+
+    def respond_to_missing?(method_name, include_private = false)
+      method_name.to_s.end_with?("?") || super
+    end
+
+    def method_missing(symbol, *args)
+      attribute = symbol.to_s.chomp("?")
+
+      if symbol.to_s.end_with?("?") && respond_to?(attribute)
+        define_singleton_method symbol do
+          attribute_value = send(attribute.to_sym)
+
+          # Same as ActiveSupport’s #present?
+          attribute_value.respond_to?(:empty?) ? !attribute_value.empty? : !!attribute_value
+        end
+
+        return send(symbol)
+      end
+
+      super symbol, *args
+    end
   end
 end

spec/service_actor/result_spec.rb

@@ -0,0 +1,97 @@
+# frozen_string_literal: true
+
+RSpec.describe ServiceActor::Result do
+  it "defines a method ending with *? suffix for each attribute" do
+    result = described_class.new
+    result.name = "Sunny"
+
+    expect(result.respond_to?(:name?)).to eq true
+  end
+
+  context "when input is String" do
+    context "when is empty" do
+      it "returns false" do
+        result = described_class.new
+        result.name = ""
+
+        expect(result.name?).to eq false
+      end
+    end
+
+    context "when is not empty" do
+      it "returns true" do
+        result = described_class.new
+        result.name = "Actor"
+
+        expect(result.name?).to eq true
+      end
+    end
+  end
+
+  context "when input is Array" do
+    context "when is empty" do
+      it "returns false" do
+        result = described_class.new
+        result.options = []
+
+        expect(result.options?).to eq false
+      end
+    end
+
+    context "when is not empty" do
+      it "returns true" do
+        result = described_class.new
+        result.options = [1, 2, 3]
+
+        expect(result.options?).to eq true
+      end
+    end
+  end
+
+  context "when input is Hash" do
+    context "when empty" do
+      it "returns false" do
+        result = described_class.new
+        result.options = {}
+
+        expect(result.options?).to eq false
+      end
+    end
+
+    context "when not empty" do
+      it "returns true" do
+        result = described_class.new
+        result.options = { name: "Actor" }
+
+        expect(result.options?).to eq true
+      end
+    end
+  end
+
+  context "when input is NilClass" do
+    it "returns false" do
+      result = described_class.new
+      result.name = nil
+
+      expect(result.name?).to eq false
+    end
+  end
+
+  context "when input is TrueClass" do
+    it "returns true" do
+      result = described_class.new
+      result.name = true
+
+      expect(result.name?).to eq true
+    end
+  end
+
+  context "when input is FalseClass" do
+    it "returns true" do
+      result = described_class.new
+      result.name = false
+
+      expect(result.name?).to eq false
+    end
+  end
+end