Added zip tests

spec/step_spec.rb

@@ -1,3 +1,4 @@
+require 'zip'
 require_relative './../functions.rb'
 
 describe 'download_library' do
@@ -15,6 +16,24 @@
         expect(f.original_filename).to eq("libTrace.a.zip")
     end
 
+    it 'validate zip file contains SDK' do
+        lib_version = "latest"
+        hasSDK = false
+
+        f = download_library("https://monitoring-sdk.firebaseapp.com/#{lib_version}/libTrace.a.zip")
+
+        Zip::File.open(f.path) do |zip_file|
+            zip_file.each do |f|
+                if f.name == "libTrace.a"
+                    hasSDK = true
+                end
+            end
+        end
+
+        expect(hasSDK).to be true
+        expect(f.original_filename).to eq("libTrace.a.zip")
+    end
+
     it 'raises error if url is 404' do
         lib_version = "nonexistent"
         expect {