feat: Add client object (#34)

Signed-off-by: Jose Colella <jose.colella@gusto.com>

.rubocop.yml

@@ -22,3 +22,7 @@ Metrics/BlockLength:
 
 Gemspec/RequireMFA:
   Enabled: false
+
+Style/DocumentDynamicEvalDefinition:
+  # TODO re-enable after figuring out what it actually wants
+  Enabled: false

lib/openfeature/sdk/api.rb

@@ -46,7 +46,7 @@ def configure(&block)
       def build_client(name: nil, version: nil)
         client_options = Metadata.new(name: name, version: version).freeze
         provider = Provider::NoOpProvider.new if provider.nil?
-        Client.new(provider, client_options, context)
+        Client.new(provider: provider, client_options: client_options, context: context)
       end
     end
   end

lib/openfeature/sdk/client.rb

@@ -5,14 +5,32 @@ module SDK
     # TODO: Write documentation
     #
     class Client
+      RESULT_TYPE = %i[boolean string number object].freeze
+      SUFFIXES = %i[value details].freeze
+
       attr_reader :metadata
 
       attr_accessor :hooks
 
-      def initialize(provider, client_options, context)
+      def initialize(provider:, client_options: nil, context: nil)
         @provider = provider
-        @client_options = client_options
+        @metadata = client_options
         @context = context
+        @hooks = []
+      end
+
+      RESULT_TYPE.each do |result_type|
+        SUFFIXES.each do |suffix|
+          class_eval <<-RUBY, __FILE__, __LINE__ + 1
+            # def fetch_boolean_details(flag_key:, default_value:, evaluation_context: nil)
+            #   result = @provider.fetch_boolean_value(flag_key: flag_key, default_value: default_value, evaluation_context: evaluation_context)
+            # end
+            def fetch_#{result_type}_#{suffix}(flag_key:, default_value:, evaluation_context: nil)
+              result = @provider.fetch_#{result_type}_value(flag_key: flag_key, default_value: default_value, evaluation_context: evaluation_context)
+              #{"result.value" if suffix == :value}
+            end
+          RUBY
+        end
       end
     end
   end

lib/openfeature/sdk/provider/no_op_provider.rb

@@ -30,6 +30,8 @@ class NoOpProvider
 
         attr_reader :metadata
 
+        ResolutionDetails = Struct.new(:value, :reason, :variant, :error_code, :error_message)
+
         def initialize
           @metadata = Metadata.new(name: NAME).freeze
         end
@@ -53,7 +55,7 @@ def fetch_object_value(flag_key:, default_value:, evaluation_context: nil)
         private
 
         def no_op(default_value)
-          Struct.new("ResolutionDetails", :value, :reason)
+          ResolutionDetails.new(value: default_value, reason: REASON_NO_OP)
         end
       end
     end

spec/openfeature/sdk/client_spec.rb

@@ -0,0 +1,195 @@
+# frozen_string_literal: true
+
+require_relative "../../spec_helper"
+
+require "openfeature/sdk/client"
+require "openfeature/sdk/metadata"
+require "openfeature/sdk/provider/no_op_provider"
+
+# https://docs.openfeature.dev/docs/specification/sections/flag-evaluation#12-client-usage
+
+RSpec.describe OpenFeature::SDK::Client do
+  subject(:client) { described_class.new(provider: provider, client_options: client_metadata) }
+  let(:provider) { OpenFeature::SDK::Provider::NoOpProvider.new }
+  let(:client_metadata) { OpenFeature::SDK::Metadata.new(name: name) }
+  let(:name) { "my-openfeature-client" }
+
+  context "Requirement 1.2.1" do
+    before do
+      client.hooks << client_hook
+    end
+
+    let(:client_hook) { "some_hook" }
+
+    it "MUST provide a method to add hooks which accepts one or more API-conformant hooks, and appends them to the collection of any previously added hooks. When new hooks are added, previously added hooks are not removed." do
+      expect(client).to respond_to(:hooks)
+      expect(client.hooks).to have_attributes(size: 1).and eq([client_hook])
+    end
+  end
+
+  context "Requirement 1.2.2" do
+    it "MUST define a metadata member or accessor, containing an immutable name field or accessor of type string, which corresponds to the name value supplied during client creation." do
+      expect(client).to respond_to(:metadata)
+      expect(client.metadata).to respond_to(:name)
+      expect(client.metadata.name).to eq(name)
+    end
+  end
+
+  context "Flag evaluation" do
+    context "Requirement 1.3.1" do
+      context "Provide methods for typed flag evaluation, including boolean, numeric, string, and structure, with parameters flag key (string, required), default value (boolean | number | string | structure, required), evaluation context (optional), and evaluation options (optional), which returns the flag value." do
+        let(:flag_key) { "my-awesome-feature-flag-key" }
+
+        context "boolean value" do
+          it do
+            expect(client).to respond_to(:fetch_boolean_value)
+          end
+
+          it do
+            expect(client.fetch_boolean_value(flag_key: flag_key, default_value: false)).is_a?(FalseClass)
+          end
+
+          it do
+            expect(client.fetch_boolean_value(flag_key: flag_key, default_value: true)).is_a?(TrueClass)
+          end
+        end
+
+        context "string value" do
+          it do
+            expect(client).to respond_to(:fetch_string_value)
+          end
+
+          it do
+            expect(client.fetch_string_value(flag_key: flag_key, default_value: "default_value")).is_a?(String)
+          end
+        end
+
+        context "number value" do
+          it do
+            expect(client).to respond_to(:fetch_number_value)
+          end
+
+          context "Condition 1.3.2 - The implementation language differentiates between floating-point numbers and integers." do
+            it do
+              expect(client.fetch_number_value(flag_key: flag_key, default_value: 4)).is_a?(Integer)
+            end
+
+            it do
+              expect(client.fetch_number_value(flag_key: flag_key, default_value: 95.5)).is_a?(Float)
+            end
+          end
+        end
+
+        context "object value" do
+          it do
+            expect(client).to respond_to(:fetch_object_value)
+          end
+
+          it do
+            expect(client.fetch_object_value(flag_key: flag_key,
+                                             default_value: { data: "some-data" })).is_a?(Hash)
+          end
+        end
+      end
+    end
+
+    context "Requirement 1.4.1" do
+      context "MUST provide methods for detailed flag value evaluation with parameters flag key (string, required), default value (boolean | number | string | structure, required), evaluation context (optional), and evaluation options (optional), which returns an evaluation details structure." do
+        let(:flag_key) { "my-awesome-feature-flag-key" }
+
+        context "boolean value" do
+          it do
+            expect(client).to respond_to(:fetch_boolean_details)
+          end
+
+          it do
+            expect(client.fetch_boolean_details(flag_key: flag_key, default_value: false)).is_a?(OpenFeature::SDK::Provider::NoOpProvider::ResolutionDetails)
+          end
+
+          context "Requirement 1.4.2" do
+            it "The evaluation details structure's value field MUST contain the evaluated flag value" do
+              expect(client.fetch_boolean_details(flag_key: flag_key, default_value: true).value).is_a?(TrueClass)
+              expect(client.fetch_boolean_details(flag_key: flag_key, default_value: false).value).is_a?(FalseClass)
+            end
+          end
+
+          context "Requirement 1.4.4" do
+            it "The evaluation details structure's flag key field MUST contain the flag key argument passed to the detailed flag evaluation method." do
+              expect(client).to respond_to(:fetch_boolean_details)
+            end
+          end
+        end
+
+        context "number value" do
+          it do
+            expect(client).to respond_to(:fetch_number_details)
+          end
+
+          it do
+            expect(client.fetch_number_details(flag_key: flag_key, default_value: 1.2)).is_a?(OpenFeature::SDK::Provider::NoOpProvider::ResolutionDetails)
+            expect(client.fetch_number_details(flag_key: flag_key, default_value: 1)).is_a?(OpenFeature::SDK::Provider::NoOpProvider::ResolutionDetails)
+          end
+
+          context "Requirement 1.4.2" do
+            it "The evaluation details structure's value field MUST contain the evaluated flag value" do
+              expect(client.fetch_number_details(flag_key: flag_key, default_value: 1.0).value).is_a?(Float)
+              expect(client.fetch_number_details(flag_key: flag_key, default_value: 1).value).is_a?(Integer)
+            end
+          end
+
+          context "Requirement 1.4.4" do
+            it "The evaluation details structure's flag key field MUST contain the flag key argument passed to the detailed flag evaluation method." do
+              expect(client).to respond_to(:fetch_number_details)
+            end
+          end
+        end
+
+        context "string value" do
+          it do
+            expect(client).to respond_to(:fetch_string_details)
+          end
+
+          it do
+            expect(client.fetch_string_details(flag_key: flag_key, default_value: "some-string")).is_a?(OpenFeature::SDK::Provider::NoOpProvider::ResolutionDetails)
+          end
+
+          context "Requirement 1.4.2" do
+            it "The evaluation details structure's value field MUST contain the evaluated flag value" do
+              expect(client.fetch_string_details(flag_key: flag_key, default_value: "some-string").value).is_a?(String)
+            end
+          end
+
+          context "Requirement 1.4.4" do
+            it "The evaluation details structure's flag key field MUST contain the flag key argument passed to the detailed flag evaluation method." do
+              expect(client).to respond_to(:fetch_string_details)
+            end
+          end
+        end
+
+        context "object value" do
+          it do
+            expect(client).to respond_to(:fetch_object_details)
+          end
+
+          it do
+            expect(client.fetch_object_details(flag_key: flag_key,
+                                               default_value: { name: "some-name" })).is_a?(OpenFeature::SDK::Provider::NoOpProvider::ResolutionDetails)
+          end
+
+          context "Requirement 1.4.2" do
+            it "The evaluation details structure's value field MUST contain the evaluated flag value" do
+              expect(client.fetch_object_details(flag_key: flag_key,
+                                                 default_value: { name: "some-name" }).value).is_a?(String)
+            end
+          end
+
+          context "Requirement 1.4.4" do
+            it "The evaluation details structure's flag key field MUST contain the flag key argument passed to the detailed flag evaluation method." do
+              expect(client).to respond_to(:fetch_object_details)
+            end
+          end
+        end
+      end
+    end
+  end
+end