Change the way how the client lazy initialisation works.

lib/kosapi_client/api_client.rb

@@ -14,9 +14,9 @@ class ApiClient
     ##
     # Creates a new KOSapi client.
     #
-    def initialize(http_client, base_url = DEFAULT_KOSAPI_BASE_URL)
-      @http_client = http_client
-      @base_url = base_url
+    def initialize(config)
+      http_adapter = OAuth2HttpAdapter.new(config.credentials, config.base_url)
+      @http_client = HTTPClient.new(http_adapter)
     end
 
     def create_builder(resource_name)

lib/kosapi_client/configuration.rb

@@ -1,13 +1,21 @@
 module KOSapiClient
-  class Configuration
+  class Configuration < Struct.new(:client_id, :client_secret, :base_url)
 
-    attr_accessor :client_id, :client_secret
+    DEFAULT_OPTIONS = {
+      base_url: 'https://kosapi.fit.cvut.cz/api/3'
+    }
+
+    def initialize(options = {})
+      DEFAULT_OPTIONS.merge(options).each do |option, value|
+        self[option] = value
+      end
+    end
 
     def credentials
       if client_id && client_secret
         {client_id: client_id, client_secret: client_secret}
       else
-        raise 'No credentials set'
+        {}
       end
     end
 

lib/kosapi_client/kosapi_client.rb

@@ -1,42 +1,43 @@
 module KOSapiClient
 
-  DEFAULT_KOSAPI_BASE_URL = 'https://kosapi.fit.cvut.cz/api/3'
-
   singleton_class.class_eval do
 
-    attr_reader :client
-
-    def new(credentials, base_url = DEFAULT_KOSAPI_BASE_URL)
-      http_adapter = OAuth2HttpAdapter.new(credentials, base_url)
-      http_client = HTTPClient.new(http_adapter)
-      ApiClient.new(http_client, base_url)
+    def new(options = {})
+      ApiClient.new(Configuration.new(options))
     end
 
     def configure
-      config = Configuration.new
+      reset
       yield config
-      @client = new(config.credentials)
+      self
+    end
+
+    def client
+      @client ||= ApiClient.new(config)
     end
 
     # Calling this method clears stored ApiClient instance
     # if configured previously.
     def reset
+      @config = nil
       @client = nil
     end
 
     def method_missing(method, *args, &block)
-      if @client.nil?
-        raise "Client not configured. Either you forgot to call configure or you have typo in method name '#{method}'."
-      end
-      if @client.respond_to?(method)
-        @client.send(method, *args, &block)
+      if client.respond_to?(method)
+        client.send(method, *args, &block)
       else
         super
       end
     end
 
     def respond_to_missing?(method_name, include_private = false)
-      @client.respond_to?(method_name, include_private)
+      client.respond_to?(method_name, include_private)
+    end
+
+    private
+    def config
+      @config ||= Configuration.new
     end
 
   end

lib/kosapi_client/oauth2_http_adapter.rb

@@ -10,13 +10,15 @@ class OAuth2HttpAdapter
 
     def initialize(credentials, base_url, opts = {})
       @base_url = base_url
+      @credentials = credentials
       auth_url = opts[:auth_url] || DEFAULT_AUTH_URL
       token_url = opts[:token_url] || DEFAULT_TOKEN_URL
       MultiXml.parser = :ox # make sure to use Ox because of different namespace handling in other MultiXML parsers
       @client = OAuth2::Client.new(credentials[:client_id], credentials[:client_secret], site: base_url, authorize_url: auth_url, token_url: token_url)
     end
 
     def send_request(verb, url, options = {})
+      raise 'No credentials set' if @credentials.empty?
       token.request(verb, url, options)
     end
 

lib/kosapi_client/version.rb

@@ -1,3 +1,3 @@
 module KOSapiClient
-  VERSION = '0.3.0'
+  VERSION = '0.3.1'
 end

spec/kosapi_client/api_client_spec.rb

@@ -1,7 +1,7 @@
 require 'spec_helper'
 
 describe KOSapiClient::ApiClient do
-  subject(:client) { KOSapiClient::ApiClient.new(double) }
+  subject(:client) { KOSapiClient::ApiClient.new(KOSapiClient::Configuration.new) }
 
   it 'responds to api resource methods' do
     expect(client).to respond_to :course_events

spec/kosapi_client/configuration_spec.rb

@@ -22,8 +22,8 @@
       expect(configuration.credentials).to eq({client_id: 'foo', client_secret: 'bar'})
     end
 
-    it 'throws error when no credentials set' do
-      expect { configuration.credentials }.to raise_error(RuntimeError)
+    it 'returns empty hash when no credentials set' do
+      expect(configuration.credentials).to eq({})
     end
 
   end

spec/kosapi_client/kosapi_client_spec.rb

@@ -3,10 +3,11 @@
 describe KOSapiClient do
 
   before do
-    @client = KOSapiClient.configure do |c|
+    KOSapiClient.configure do |c|
       c.client_id = 'foo'
       c.client_secret = 'bar'
     end
+    @client = KOSapiClient.client
   end
 
   describe '.configure' do
@@ -21,7 +22,7 @@
 
     it 'cleans stored ApiClient instance' do
       KOSapiClient.reset
-      expect(KOSapiClient.client).to be_nil
+      expect(KOSapiClient.client).not_to be @client
     end
 
   end
@@ -43,9 +44,9 @@
     expect { KOSapiClient.foo }.to raise_error NoMethodError
   end
 
-  it 'throws error when calling client methods with no configured client' do
+  it 'throws error when sending request with no configured credentials' do
     KOSapiClient.reset
-    expect { KOSapiClient.course_events }.to raise_error(RuntimeError)
+    expect { KOSapiClient.course_events.items }.to raise_error(RuntimeError)
   end
 
   it 'responds to client methods' do