move validation into Client to ensure it runs

Author: simoleone

lib/openai.rb

@@ -36,9 +36,8 @@ def call(env)
   end
 
   class Configuration
-    attr_reader :azure_token_provider
     attr_accessor :api_type, :api_version, :organization_id, :uri_base, :request_timeout,
-                  :extra_headers, :access_token
+                  :extra_headers, :access_token, :azure_token_provider
 
     DEFAULT_API_VERSION = "v1".freeze
     DEFAULT_URI_BASE = "https://api.openai.com/".freeze
@@ -54,15 +53,6 @@ def initialize
       @extra_headers = {}
       @azure_token_provider = nil
     end
-
-    def azure_token_provider=(provider)
-      unless provider.nil? || provider.respond_to?(:to_proc)
-        raise ConfigurationError,
-              "OpenAI Azure AD token provider must be a Proc, Lambda, or respond to to_proc."
-      end
-
-      @azure_token_provider = provider&.to_proc
-    end
   end
 
   class << self

lib/openai/client.rb

@@ -23,6 +23,7 @@ def initialize(config = {}, &faraday_middleware)
       end
       @faraday_middleware = faraday_middleware
       validate_credential_config!
+      validate_azure_credential_provider!
     end
 
     def chat(parameters: {})
@@ -104,5 +105,16 @@ def validate_credential_config!
       raise ConfigurationError,
             "OpenAI access token or Azure token provider missing! See https://github.com/alexrudall/ruby-openai#usage"
     end
+
+    def validate_azure_credential_provider!
+      return if @azure_token_provider.nil?
+
+      unless @azure_token_provider.respond_to?(:to_proc)
+        raise ConfigurationError,
+              "OpenAI Azure AD token provider must be a Proc, Lambda, or respond to to_proc."
+      end
+
+      @azure_token_provider = @azure_token_provider&.to_proc
+    end
   end
 end