Add offline mode spec

Author: zachaysan

spec/sdk/offline_mode_spec.rb

@@ -0,0 +1,72 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+
+RSpec.describe Flagsmith::Client do
+  it "gets environment flags with an environment document with an offline_handler" do
+    offline_handler = \
+    Flagsmith::OfflineHandlers::LocalFileHandler.new("spec/sdk/fixtures/environment.json")
+
+    flagsmith = Flagsmith::Client.new(
+      offline_mode: true,
+      offline_handler: offline_handler,
+    )
+
+    response = flagsmith.get_environment_flags
+    expect(response.count).to eq(1)
+    expect(response.first[-1].feature_name).to eq("some_feature")
+  end
+
+  it "gets identity flags with an offline_handler" do
+    offline_handler = \
+    Flagsmith::OfflineHandlers::LocalFileHandler.new("spec/sdk/fixtures/environment.json")
+
+    flagsmith = Flagsmith::Client.new(
+      offline_mode: true,
+      offline_handler: offline_handler,
+    )
+
+    response = flagsmith.get_identity_flags("some_identity")
+    expect(response.first[-1].feature_name).to eq("some_feature")
+  end
+
+  it "raises an error if offline_mode is present but offline_handler is missing" do
+    expect {
+      flagsmith = Flagsmith::Client.new(offline_mode: true)
+    }.to raise_error(
+           Flagsmith::ClientError,
+           "The offline_mode config param requires a matching offline_handler."
+         )
+  end
+
+  it "raises an error if both the default_flag_handler and offline_handler are used" do
+    default_flag_handler = lambda { |feature_name|
+      Flagsmith::Flags::DefaultFlag.new(enabled: false, value: {}.to_json)
+    }
+    offline_handler = \
+    Flagsmith::OfflineHandlers::LocalFileHandler.new("spec/sdk/fixtures/environment.json")
+    expect {
+      Flagsmith::Client.new(
+        default_flag_handler: default_flag_handler,
+        offline_handler: offline_handler,
+      )
+    }.to raise_error(
+           Flagsmith::ClientError,
+           "Cannot use offline_handler and default_flag_handler at the same time."
+         )
+  end
+end
+
+RSpec.describe Flagsmith::Flags::Collection do
+  it "works with get_flag with an offline_handler" do
+    offline_handler = \
+    Flagsmith::OfflineHandlers::LocalFileHandler.new("spec/sdk/fixtures/environment.json")
+
+    flags_collection = Flagsmith::Flags::Collection.new(offline_handler: offline_handler)
+    flag = flags_collection.get_flag("some_feature")
+
+    expect(flag.feature_name).to eq("some_feature")
+    expect(flag.value).to eq("some-value")
+  end
+end