add check for auth parameters while initializing

Author: Jay Parekh

lib/imagekit/imagekit.rb

@@ -16,6 +16,15 @@ class ImageKitClient
     attr_reader :file
 
     def initialize(private_key, public_key, url_endpoint, transformation_pos = nil, options = nil)
+      
+      unless(private_key.is_a?(String) && public_key.is_a?(String) && url_endpoint.is_a?(String))
+        raise ArgumentError, "ImageKit Parameters should be valid string"
+      end
+      
+      unless(private_key.to_s.strip.length != 0 && public_key.to_s.strip.length != 0 && url_endpoint.to_s.strip.length != 0)
+        raise ArgumentError, "ImageKit Parameters cannot be blank"
+      end
+
       @private_key = private_key
       @public_key = public_key
       @url_endpoint = url_endpoint

test/imagekit/imagekit_test.rb

@@ -3,6 +3,21 @@
 require "rspec/autorun"
 
 RSpec.describe "FileUploadTest" do
+
+    it "test_initialization_with_parameters_missing" do
+      request_obj = double
+      expect {
+        ImageKit::ImageKitClient.new("  ", PUBLIC_KEY, URL_ENDPOINT)
+    }.to raise_error(ArgumentError)
+    end
+
+    it "test_initialization_with_non_string_parameters" do
+      request_obj = double
+      expect {
+        ImageKit::ImageKitClient.new({RANDOM: "RANDOM"}, PUBLIC_KEY, URL_ENDPOINT)
+    }.to raise_error(ArgumentError)
+    end
+
     it "test_upload_with_valid_expected_success" do
       request_obj = double
       allow(ImageKitRequest)