Allow custom parser

Paves the way for returning what's in Amazon's Open API models

CHANGELOG.md

@@ -7,6 +7,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Added
 
+- Allow custom parser
 - Marketplace.id and Marketplace.ids shorthands
 
 ## [3.0.0] - 2024-10-04

lib/peddler/api.rb

@@ -5,6 +5,7 @@
 require "peddler/endpoint"
 require "peddler/error"
 require "peddler/marketplace"
+require "peddler/response_decorator"
 require "peddler/version"
 
 module Peddler
@@ -13,6 +14,11 @@ class API
     class CannotSandbox < StandardError; end
     class MustSandbox < StandardError; end
 
+    class << self
+      # @return [#call]
+      attr_accessor :parser
+    end
+
     # @return [Peddler::Endpoint]
     attr_reader :endpoint
 
@@ -122,10 +128,19 @@ def meter(rate_limit)
           raise error if error
         end
 
-        response
+        ResponseDecorator.decorate(response, parser:)
       end
     end
 
+    # @param [#call]
+    attr_writer :parser
+
+    # @!attribute [r]
+    # @return [#call]
+    def parser
+      @parser || self.class.parser
+    end
+
     private
 
     def user_agent

lib/peddler/response_decorator.rb

@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+require "delegate"
+require "forwardable"
+
+module Peddler
+  # Wraps HTTP::Response to allow custom parsing
+  class ResponseDecorator < SimpleDelegator
+    extend Forwardable
+
+    # @!method dig(*key)
+    #   Delegates to the Hash returned by {Response#to_h} to extract a nested
+    #   value specified by the sequence of keys
+    #
+    #   @param [String] key one or more keys
+    #   @see https://ruby-doc.org/core/Hash.html#method-i-dig
+    def_delegator :to_h, :dig
+
+    class << self
+      # Decorates an HTTP::Response
+      #
+      # @param [HTTP::Response] response
+      # @param [nil, #call] parser (if any)
+      # @return [ResponseDecorator]
+      def decorate(response, parser: nil)
+        new(response).tap do |decorator|
+          decorator.parser = parser
+        end
+      end
+    end
+
+    # @return [#call]
+    attr_accessor :parser
+
+    def parse
+      parser ? parser.call(__getobj__) : __getobj__.parse
+    end
+
+    # Converts the response body to a Hash
+    #
+    # @return [Hash]
+    def to_h
+      (parser && parser.respond_to?(:to_h) ? parser : parse).to_h
+    end
+  end
+end

test/peddler/custom_parser_test.rb

@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+require "helper"
+
+require "peddler/api/reports_2021_06_30"
+
+module Peddler
+  class CustomParserTest < Minitest::Test
+    include FeatureHelpers
+
+    def test_custom_parser_on_instance
+      api.parser = custom_parser
+      res = api.get_report("1234567")
+
+      assert_nil(api_class.parser)
+      assert(api.parser)
+      assert(res.dig(:reportId))
+    end
+
+    def test_custom_parser_on_class
+      klass = Class.new(api_class)
+      klass.parser = custom_parser
+      access_token = request_access_token(grantless: false)
+      api = klass.new(aws_region, access_token)
+      res = api.get_report("1234567")
+
+      assert_nil(api_class.parser)
+      assert(klass.parser)
+      assert(res.dig(:reportId))
+    end
+
+    private
+
+    def custom_parser
+      ->(response) { JSON.parse(response, symbolize_names: true) }
+    end
+
+    def api_class
+      API::Reports20210630
+    end
+  end
+end

test/peddler/response_decorator_test.rb

@@ -0,0 +1,70 @@
+# frozen_string_literal: true
+
+require "helper"
+require "peddler/response_decorator"
+
+module Peddler
+  class ResponseDecoratorTest < Minitest::Test
+    def test_parses
+      decorator = ResponseDecorator.decorate(response)
+
+      assert_equal(payload, decorator.parse)
+    end
+
+    def test_to_h
+      decorator = ResponseDecorator.decorate(response)
+
+      assert_equal(payload, decorator.to_h)
+    end
+
+    def test_dig
+      decorator = ResponseDecorator.decorate(response)
+
+      assert(decorator.dig("foo"))
+    end
+
+    def test_parses_with_custom_parser
+      decorator = ResponseDecorator.decorate(
+        response, parser: ->(response) { JSON.parse(response, symbolize_names: true) }
+      )
+
+      assert_equal(payload_with_symbolized_keys, decorator.parse)
+    end
+
+    def test_to_h_with_custom_parser
+      decorator = ResponseDecorator.decorate(
+        response, parser: ->(response) { JSON.parse(response, symbolize_names: true) }
+      )
+
+      assert_equal(payload_with_symbolized_keys, decorator.to_h)
+    end
+
+    def test_dig_with_custom_parser
+      decorator = ResponseDecorator.decorate(
+        response, parser: ->(response) { JSON.parse(response, symbolize_names: true) }
+      )
+
+      assert(decorator.dig(:foo))
+    end
+
+    private
+
+    def response
+      HTTP::Response.new(
+        body: JSON.dump(payload),
+        headers: { "Content-Type" => "application/json" },
+        status: nil,
+        version: nil,
+        request: nil,
+      )
+    end
+
+    def payload
+      { "foo" => "bar" }
+    end
+
+    def payload_with_symbolized_keys
+      payload.transform_keys(&:to_sym)
+    end
+  end
+end