Add Fountain::UnexpectedHTTPError to provide more error context

lib/fountain.rb

@@ -19,6 +19,28 @@ class AuthenticationError < HTTPError; end
 
   class InvalidMethodError < HTTPError; end
 
+  class UnexpectedHTTPError < HTTPError
+    def initialize(response)
+      @response = response
+      super "Unexpected http response code: #{response.code}"
+    end
+
+    def response_code
+      @response.code
+    end
+
+    def parsed_body
+      JSON.parse(@response.body)
+    rescue JSON::ParserError
+      @response.body
+    end
+
+    def response_message
+      body = parsed_body
+      body['message'] if body.is_a? Hash
+    end
+  end
+
   class JsonParseError < Error; end
 
   class MissingApiKeyError < Error; end

lib/fountain/api/request_helper.rb

@@ -43,7 +43,7 @@ def check_response(response, expected_response = nil)
         when *[expected_response].flatten then nil
         when Net::HTTPUnauthorized then raise Fountain::AuthenticationError
         when Net::HTTPNotFound then raise Fountain::NotFoundError
-        else raise HTTPError, "Invalid http response code: #{response.code}"
+        else raise Fountain::UnexpectedHTTPError, response
         end
       end
 

spec/fountain/api/applicants_spec.rb

@@ -432,7 +432,7 @@
           invalid_arg: 'should not be included',
           funnel_id: 'funnel-id'
         )
-      end.to raise_error Fountain::HTTPError, 'Invalid http response code: 422'
+      end.to raise_error Fountain::UnexpectedHTTPError, 'Unexpected http response code: 422'
     end
   end
 

spec/fountain/fountain_spec.rb

@@ -0,0 +1,81 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Fountain do
+  describe Fountain::Error do
+    it { is_expected.to be_a ::StandardError }
+  end
+
+  describe Fountain::HTTPError do
+    it { is_expected.to be_a Fountain::Error }
+  end
+
+  describe Fountain::NotFoundError do
+    it { is_expected.to be_a Fountain::HTTPError }
+  end
+
+  describe Fountain::AuthenticationError do
+    it { is_expected.to be_a Fountain::HTTPError }
+  end
+
+  describe Fountain::InvalidMethodError do
+    it { is_expected.to be_a Fountain::HTTPError }
+  end
+
+  describe Fountain::UnexpectedHTTPError do
+    subject(:unexpected_http_error) { described_class.new(response) }
+
+    let(:response) do
+      Net::HTTPUnprocessableEntity.new('1.1', '422', 'Unprocessable Entity').tap do |r|
+        r.body = response_body
+        r.instance_variable_set :@read, true
+      end
+    end
+    let(:response_body) { '{"message": "Applicant is already on this stage"}' }
+
+    it { is_expected.to be_a Fountain::HTTPError }
+
+    describe '#response_code' do
+      subject(:response_code) { unexpected_http_error.response_code }
+
+      it { is_expected.to eq '422' }
+    end
+
+    describe '#parsed_body'do
+      subject(:parsed_body) { unexpected_http_error.parsed_body }
+
+      it { is_expected.to eq('message' => 'Applicant is already on this stage') }
+
+      context 'when the response body is not JSON' do
+        let(:response_body) { 'This isnt JSON' }
+
+        it { is_expected.to eq 'This isnt JSON' }
+      end
+    end
+
+    describe '#response_message' do
+      subject(:response_message) { unexpected_http_error.response_message }
+
+      it { is_expected.to eq 'Applicant is already on this stage' }
+
+      context 'when the response body is not JSON' do
+        let(:response_body) { 'This isnt JSON' }
+
+        it { is_expected.to be_nil }
+      end
+    end
+  end
+
+  describe Fountain::JsonParseError do
+    it { is_expected.to be_a Fountain::Error }
+  end
+
+  describe Fountain::MissingApiKeyError do
+    it { is_expected.to be_a Fountain::Error }
+  end
+
+  describe Fountain::StatusError do
+    it { is_expected.to be_a Fountain::Error }
+  end
+end