Support multiple response schemas for OpenAPI 2 (#433)

Author: renatolond

lib/committee/drivers/open_api_2/driver.rb

@@ -85,17 +85,17 @@ def schema_class
 
         def find_best_fit_response(link_data)
           if response_data = link_data["responses"]["200"] || response_data = link_data["responses"][200]
-            [200, response_data]
+            200
           elsif response_data = link_data["responses"]["201"] || response_data = link_data["responses"][201]
-            [201, response_data]
+            201
           else
             # Sort responses so that we can try to prefer any 3-digit status code.
             # If there are none, we'll just take anything from the list.
             ordered_responses = link_data["responses"].select { |k, v| k.to_s =~ /[0-9]{3}/ }
             if first = ordered_responses.first
-              [first[0].to_i, first[1]]
+              first[0].to_i
             else
-              [nil, nil]
+              nil
             end
           end
         end
@@ -165,18 +165,16 @@ def parse_routes!(data, schema, store)
                 schemas_data["properties"][href]["properties"][method] = schema_data
               end
 
-              # Arbitrarily pick one response for the time being. Prefers in order:
-              # a 200, 201, any 3-digit numerical response, then anything at all.
-              status, response_data = find_best_fit_response(link_data)
-              if status
-                link.status_success = status
+              target_schemas_data["properties"][href]["properties"][method] ||= { "properties" => {} }
+              link_data["responses"].each do |key, response_data|
+                status = key.to_i
+                next unless response_data["schema"]
 
-                # A link need not necessarily specify a target schema.
-                if response_data["schema"]
-                  target_schemas_data["properties"][href]["properties"][method] = response_data["schema"]
-                end
+                target_schemas_data["properties"][href]["properties"][method]["properties"][status] = response_data["schema"]
               end
 
+              link.status_success = find_best_fit_response(link_data)
+
               rx = %r{^#{href_to_regex(link.href)}$}
               Committee.log_debug "Created route: #{link.method} #{link.href} (regex #{rx})"
 
@@ -206,7 +204,10 @@ def parse_routes!(data, schema, store)
               end
 
               # response
-              link.target_schema = target_schemas.properties[link.href].properties[method]
+              link.target_schemas = {}
+              target_schemas.properties[link.href].properties[method].properties.each do |status, schema|
+                link.target_schemas[status] = schema
+              end
             end
           end
 

lib/committee/drivers/open_api_2/link.rb

@@ -23,13 +23,20 @@ class Link
 
         # The link's output schema. i.e. How we validate an endpoint's response
         # data.
-        attr_accessor :target_schema
+        attr_accessor :target_schemas
 
         attr_accessor :header_schema
 
         def rel
           raise "Committee: rel not implemented for OpenAPI"
         end
+
+        def target_schema
+          target_schemas[status_success] ||
+            target_schemas[200] ||
+            target_schemas[201] ||
+            target_schemas.values.first
+        end
       end
     end
   end

lib/committee/schema_validator/hyper_schema/response_validator.rb

@@ -11,7 +11,14 @@ def initialize(link, options = {})
           @validate_success_only = options[:validate_success_only]
           @allow_blank_structures = options[:allow_blank_structures]
 
-          @validator = JsonSchema::Validator.new(target_schema(link))
+          @validators = {}
+          if link.is_a? Drivers::OpenAPI2::Link
+            link.target_schemas.each do |status, schema|
+              @validators[status] = JsonSchema::Validator.new(target_schema(link))
+            end
+          else
+            @validators[link.status_success] = JsonSchema::Validator.new(target_schema(link))
+          end
         end
 
         def call(status, headers, data)
@@ -45,9 +52,12 @@ def call(status, headers, data)
           end
 
           begin
-            if Committee::Middleware::ResponseValidation.validate?(status, validate_success_only) && !@validator.validate(data)
-              errors = JsonSchema::SchemaError.aggregate(@validator.errors).join("\n")
-              raise InvalidResponse, "Invalid response.\n\n#{errors}"
+            if Committee::Middleware::ResponseValidation.validate?(status, validate_success_only)
+              raise InvalidResponse, "Invalid response.#{@link.href} status code #{status} definition does not exist" if @validators[status].nil?
+              if !@validators[status].validate(data)
+                errors = JsonSchema::SchemaError.aggregate(@validators[status].errors).join("\n")
+                raise InvalidResponse, "Invalid response.\n\n#{errors}"
+              end
             end
           rescue => e
             raise InvalidResponse, "Invalid response.\n\nschema is undefined" if /undefined method .all_of. for nil/ =~ e.message

test/drivers/open_api_2/link_test.rb

@@ -11,7 +11,7 @@
     @link.method = "GET"
     @link.status_success = 200
     @link.schema = { "title" => "input" }
-    @link.target_schema = { "title" => "target" }
+    @link.target_schemas = { 200 => { "title" => "target" } }
   end
 
   it "uses set #enc_type" do

test/schema_validator/hyper_schema/response_generator_test.rb

@@ -74,62 +74,68 @@
 
   it "generates first enum value for a schema with enum" do
     link = Committee::Drivers::OpenAPI2::Link.new
-    link.target_schema = JsonSchema::Schema.new
-    link.target_schema.enum = ["foo"]
-    link.target_schema.type = ["string"]
+    target_schema = JsonSchema::Schema.new
+    target_schema.enum = ["foo"]
+    target_schema.type = ["string"]
+    link.target_schemas = { 200 => target_schema }
     data, _schema = Committee::SchemaValidator::HyperSchema::ResponseGenerator.new.call(link)
     assert_equal("foo", data)
   end
 
   it "generates basic types" do
     link = Committee::Drivers::OpenAPI2::Link.new
-    link.target_schema = JsonSchema::Schema.new
+    target_schema = JsonSchema::Schema.new
+    link.target_schemas = { 200 => target_schema }
 
-    link.target_schema.type = ["integer"]
+    target_schema.type = ["integer"]
     data, _schema = Committee::SchemaValidator::HyperSchema::ResponseGenerator.new.call(link)
     assert_equal 0, data
 
-    link.target_schema.type = ["null"]
+    target_schema.type = ["null"]
     data, _schema = Committee::SchemaValidator::HyperSchema::ResponseGenerator.new.call(link)
     assert_nil data
 
-    link.target_schema.type = ["string"]
+    target_schema.type = ["string"]
     data, _schema = Committee::SchemaValidator::HyperSchema::ResponseGenerator.new.call(link)
     assert_equal "", data
   end
 
   it "generates an empty array for an array type" do
     link = Committee::Drivers::OpenAPI2::Link.new
-    link.target_schema = JsonSchema::Schema.new
-    link.target_schema.type = ["array"]
+    target_schema = JsonSchema::Schema.new
+    link.target_schemas = { 200 => target_schema }
+    target_schema.type = ["array"]
     data, _schema = Committee::SchemaValidator::HyperSchema::ResponseGenerator.new.call(link)
     assert_equal([], data)
   end
 
   it "generates an empty object for an object with no fields" do
     link = Committee::Drivers::OpenAPI2::Link.new
-    link.target_schema = JsonSchema::Schema.new
-    link.target_schema.type = ["object"]
+    target_schema = JsonSchema::Schema.new
+    link.target_schemas = { 200 => target_schema }
+    target_schema.type = ["object"]
     data, _schema = Committee::SchemaValidator::HyperSchema::ResponseGenerator.new.call(link)
     assert_equal({}, data)
   end
 
   it "prefers an example to a built-in value" do
     link = Committee::Drivers::OpenAPI2::Link.new
-    link.target_schema = JsonSchema::Schema.new
+    target_schema = JsonSchema::Schema.new
+    link.target_schemas = { 200 => target_schema }
 
-    link.target_schema.data = { "example" => 123 }
-    link.target_schema.type = ["integer"]
+    target_schema.data = { "example" => 123 }
+    target_schema.type = ["integer"]
 
     data, _schema = Committee::SchemaValidator::HyperSchema::ResponseGenerator.new.call(link)
     assert_equal 123, data
   end
 
   it "prefers non-null types to null types" do
     link = Committee::Drivers::OpenAPI2::Link.new
-    link.target_schema = JsonSchema::Schema.new
+    target_schema = JsonSchema::Schema.new
+    link.target_schemas = { 200 => target_schema }
 
-    link.target_schema.type = ["null", "integer"]
+    target_schema.type = ["null", "integer"]
     data, _schema = Committee::SchemaValidator::HyperSchema::ResponseGenerator.new.call(link)
     assert_equal 0, data
   end