chore: add type signatures and type checker for CI

Signed-off-by: Manuel Schönlaub <[email protected]>

.github/workflows/main.yml

@@ -43,6 +43,17 @@ jobs:
       - run: bundle install
       - name: Rubocop
         run: bundle exec rubocop --color
+  steep:
+    runs-on: ubuntu-latest
+    name: Steep
+    steps:
+      - uses: actions/checkout@v3
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 3.2
+      - run: bundle install
+      - name: Steep
+        run: bundle exec steep check
   # check the status of other jobs, so we can have a single job dependency for branch protection
   # https://github.com/community/community/discussions/4324#discussioncomment-3477871
   status:

lib/openfeature/sdk/metadata.rb

@@ -26,7 +26,7 @@ def initialize(name:, version: nil)
       end
 
       def ==(other)
-        raise ArgumentError("Expected comparison to be between Metadata object") unless other.is_a?(Metadata)
+        raise ArgumentError, "Expected comparison to be between Metadata object" unless other.is_a?(Metadata)
 
         @name == other.name && @version == other.version
       end

openfeature-sdk.gemspec

@@ -35,4 +35,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "rake", "~> 13.0"
   spec.add_development_dependency "rspec", "~> 3.12.0"
   spec.add_development_dependency "rubocop", "~> 1.37.1"
+  spec.add_development_dependency "steep", "~> 1.5.0"
 end

sig/openfeature/sdk.rbs

@@ -1,5 +1,5 @@
-module Openfeature
-  module Sdk
+module OpenFeature
+  module SDK
     VERSION: String
     # See the writing guide of rbs: https://github.com/ruby/rbs#guides
   end

sig/openfeature/sdk/_hook.rbs

@@ -0,0 +1,31 @@
+type flagValue = bool | Numeric | String | Hash[String, untyped]
+type flagValueType = :bool | :integer | :float | :string | :object
+type evaluationContext = { targeting_key: String? }
+type evaluationDetails = { flag_key: String, flag_value?: flagValue }
+
+type hookContext[T] = {
+    flag_key: String,
+    flag_value_type: flagValueType,
+    evaluation_context: evaluationContext,
+    default_value: T,
+  }
+
+type hookHints = Hash[String, flagValue]
+
+interface _BeforeHook
+  def before: (evaluationContext, ?hookHints) -> (evaluationContext | void)
+end
+
+interface _AfterHook[T]
+  def after: (hookContext[T], evaluationDetails, ?hookHints) -> void
+end
+
+interface _ErrorHook[T]
+  def error: (hookContext[T], Exception, ?hookHints) -> void
+end
+
+interface _FinallyHook[T]
+  def finally: (hookContext[T], ?hookHints) -> void
+end
+
+type hook = _BeforeHook | _AfterHook[flagValue] | _ErrorHook[flagValue] | _FinallyHook[flagValue]

sig/openfeature/sdk/api.rbs

@@ -0,0 +1,22 @@
+module OpenFeature
+  module SDK
+
+    interface _Configuration
+      def context: () -> void
+    end
+
+    class API
+      include _Configuration
+      extend Forwardable
+
+      attr_reader configuration: Configuration
+
+      def build_client: -> Client
+
+      def configure: () { (Configuration) -> void } -> void
+
+      # Singleton's RBS doesn't quite work
+      def self.instance: () -> instance
+    end
+  end
+end

sig/openfeature/sdk/client.rbs

@@ -0,0 +1,17 @@
+module OpenFeature
+  module SDK
+    class Client
+      RESULT_TYPE: Array[Symbol]
+      SUFFIXES: Array[Symbol]
+
+      @context: evaluationContext
+      @hooks: Array[hook]
+
+      attr_accessor hooks: Array[hook]
+      attr_reader metadata: Metadata?
+      attr_reader provider: untyped
+
+      def initialize: (provider: untyped , client_options: untyped, context: untyped) -> void
+    end
+  end
+end

sig/openfeature/sdk/configuration.rbs

@@ -0,0 +1,19 @@
+
+module Concurrent
+  class Array[T] < ::Array[T]
+    def initialize: (?::Array[T]) -> void
+  end
+end
+
+module OpenFeature
+  module SDK
+    class Configuration
+      extend Forwardable
+
+      attr_accessor context: evaluationContext
+      attr_accessor hooks: [hook]
+      attr_accessor metadata: Metadata
+      attr_accessor provider: untyped
+    end
+  end
+end

sig/openfeature/sdk/metadata.rbs

@@ -0,0 +1,12 @@
+module OpenFeature
+  module SDK
+    class Metadata
+      attr_reader name: String
+      attr_reader version: String?
+
+      def initialize: (name: String, ?version: String?) -> void
+
+      def ==: (untyped other) -> untyped
+    end
+  end
+end

sig/openfeature/sdk/provider/no_op_provider.rbs

@@ -0,0 +1,32 @@
+module OpenFeature
+  module SDK
+    module Provider
+      class NoOpProvider
+        REASON_NO_OP: String
+        NAME: String
+
+        class ResolutionDetails[T] < ::Struct[T]
+          attr_reader value(): T
+          attr_reader reason(): untyped
+          attr_reader variant(): untyped
+          attr_reader error_code(): untyped
+          attr_reader error_message(): untyped
+        end
+
+        attr_reader metadata: Metadata
+
+        def fetch_boolean_value: (flag_key: String, default_value: bool?, ?evaluation_context: evaluationContext?) -> ResolutionDetails[bool]
+
+        def fetch_string_value: (flag_key: String, default_value: String?, ?evaluation_context: evaluationContext?) -> ResolutionDetails[String]
+
+        def fetch_number_value: (flag_key: String, default_value: Numeric?, ?evaluation_context: evaluationContext?) -> ResolutionDetails[Numeric]
+
+        def fetch_object_value: (flag_key: String, default_value: Hash[untyped, untyped]?, ?evaluation_context: evaluationContext?) -> ResolutionDetails[Hash[untyped, untyped]]
+
+        private
+
+        def no_op:(default_value: flagValue) -> ResolutionDetails[flagValue]
+      end
+    end
+  end
+end