implement JSON schema generation and validation

airborne.gemspec

@@ -12,5 +12,7 @@ Gem::Specification.new do |s|
   s.add_runtime_dependency 'rest-client', '~> 1.7', '>= 1.7.3' # version 1.7.3 fixes security vulnerability https://github.com/brooklynDev/airborne/issues/41
   s.add_runtime_dependency 'rack-test', '~> 0.6', '>= 0.6.2'
   s.add_runtime_dependency 'activesupport', '>= 3.0.0', '>= 3.0.0'
+  s.add_runtime_dependency 'json-schema'
+  s.add_runtime_dependency 'json-schema-generator'
   s.add_development_dependency 'webmock', '~> 0'
 end

lib/airborne.rb

@@ -16,6 +16,10 @@
   config.add_setting :rack_app
   config.add_setting :requester_type
   config.add_setting :requester_module
+  config.add_setting :generate_schema, default: false
+  config.add_setting :schema_path, default: 'schema'
+  config.add_setting :validate_schema, default: false
+  config.add_setting :schema_version, default: 'draft4'
   config.before do |example|
     config.match_expected = example.metadata[:match_expected].nil? ?
       Airborne.configuration.match_expected_default? : example.metadata[:match_expected]

lib/airborne/base.rb

@@ -7,7 +7,7 @@ class InvalidJsonError < StandardError; end
 
   include RequestExpectations
 
-  attr_reader :response, :headers, :body
+  attr_reader :response, :headers, :body, :rest_url, :rest_method
 
   def self.configure
     RSpec.configure do |config|
@@ -30,22 +30,27 @@ def self.configuration
   end
 
   def get(url, headers = nil)
+    @rest_method = :get
     @response = make_request(:get, url, headers: headers)
   end
 
   def post(url, post_body = nil, headers = nil)
+    @rest_method = :post
     @response = make_request(:post, url, body: post_body, headers: headers)
   end
 
   def patch(url, patch_body = nil, headers = nil)
+    @rest_method = :patch
     @response = make_request(:patch, url, body: patch_body, headers: headers)
   end
 
   def put(url, put_body = nil, headers = nil)
+    @rest_method = :put
     @response = make_request(:put, url, body: put_body, headers: headers)
   end
 
   def delete(url, delete_body = nil, headers = nil)
+    @rest_method = :delete
     @response = make_request(:delete, url, body: delete_body, headers: headers)
   end
 
@@ -76,6 +81,7 @@ def json_body
   private
 
   def get_url(url)
+    @rest_url = url
     base = Airborne.configuration.base_url || ''
     base + url
   end

lib/airborne/request_expectations.rb

@@ -1,6 +1,7 @@
 require 'rspec'
 require 'date'
 require 'rack/utils'
+require 'json-schema'
 
 module Airborne
   class ExpectationError < StandardError; end
@@ -44,6 +45,28 @@ def expect_header_contains(key, content)
       expect_header_impl(key, content, true)
     end
 
+    def expect_json_schema(file=nil)
+      path = "#{Dir.pwd}/#{Airborne.configuration.schema_path}#{rest_url}"
+      path = path.tr('?', '/').tr('&', '/').tr('[', '-').tr(']', '')
+      path = path.gsub(/\/\d*\//, "/ID/").gsub(/\/\d*$/, "/ID").tr('=', '/')
+
+      file ||= "#{path}/#{rest_method}.schema"
+
+      schema_details = JSON.parse File.read(file)
+      schema = if schema_details['items']
+                 schema_details['items']
+               else
+                 schema_details['properties']
+               end
+
+      expect { JSON::Validator.validate!(schema, json_body) }.not_to raise_error
+    rescue Errno::ENOENT => ex
+      warn "Can not verify schema; #{ex.message}"
+    ensure
+      json_file = file.gsub('.schema', '.json')
+      File.delete json_file if File.exist? json_file
+    end
+
     def optional(hash)
       OptionalHashTypeExpectations.new(hash)
     end

lib/airborne/rest_client_requester.rb

@@ -1,22 +1,25 @@
 require 'rest_client'
+require 'json-schema-generator'
 
 module Airborne
   module RestClientRequester
     def make_request(method, url, options = {})
       headers = base_headers.merge(options[:headers] || {})
-      res = if method == :post || method == :patch || method == :put
+      if method == :post || method == :patch || method == :put
         begin
           request_body = options[:body].nil? ? '' : options[:body]
           request_body = request_body.to_json if options[:body].is_a?(Hash)
-          RestClient.send(method, get_url(url), request_body, headers)
+          res = RestClient.send(method, get_url(url), request_body, headers)
+          generate_json(method, url, res) if Airborne.configuration.validate_schema
         rescue RestClient::Exception => e
-          e.response
+          res = e.response
         end
       else
         begin
-          RestClient.send(method, get_url(url), headers)
+          res = RestClient.send(method, get_url(url), headers)
+          generate_json(method, url, res) if Airborne.configuration.validate_schema
         rescue RestClient::Exception => e
-          e.response
+          res = e.response
         end
       end
       res
@@ -27,5 +30,26 @@ def make_request(method, url, options = {})
     def base_headers
       { content_type: :json }.merge(Airborne.configuration.headers || {})
     end
+
+    def generate_json(method, url, res)
+      path = "#{Dir.pwd}/#{Airborne.configuration.schema_path}#{url}/"
+      path = path.tr('?', '/').tr('&', '/').tr('[', '-').tr(']', '')
+      path = path.gsub(/\/\d*\//, "/ID/").gsub(/\/\d*$/, "/ID").tr('=', '/')
+
+      file = "#{path}/#{method}.json"
+
+      unless File.exist?(file.gsub('.json', '.schema'))
+        return unless Airborne.configuration.generate_schema # no schema to compare against
+        FileUtils.mkdir_p(path)
+      end
+
+      File.open(file, 'w') { |f| f.puts res }
+
+      schema_file = file.gsub(".json", ".schema")
+      return unless File.exist?(schema_file) || Airborne.configuration.generate_schema
+
+      schema = JSON::SchemaGenerator.generate file, File.read(file), {:schema_version => Airborne.configuration.schema_version}
+      File.open(schema_file, 'w') { |f| f.puts schema }
+    end
   end
 end