Implements exception throwing when making requests

README.md

@@ -135,6 +135,26 @@ users_endpoint = api.users(55)
 users_endpoint.extension = :xml
 ```
 
+### Handling Exceptions
+
+Blanket will raise exceptions for HTTP errors encountered while making requests. Exception subclasses are raised for well known errors (404, 500, etc.) but for other status codes a default `Blanket::Exception` will be raised instead.
+
+```ruby
+begin
+  api.thingamajig.get
+rescue Blanket::ResourceNotFound => e
+  e.code
+  # => 404
+
+  e.message
+  # => "404: Resource Not Found"
+
+  # The HTTP body, ie. the error message sent by the server
+  e.body
+  # => "Could not find this resource!"
+end
+```
+
 ## Contributing
 
 1. Fork it ( https://github.com/[my-github-username]/blanket/fork )

lib/blanket.rb

@@ -1,6 +1,7 @@
-require "blanket/version"
-require "blanket/response"
-require "blanket/wrapper"
+require_relative "blanket/version"
+require_relative "blanket/response"
+require_relative "blanket/exception"
+require_relative "blanket/wrapper"
 require 'httparty'
 
 module Blanket

lib/blanket/exception.rb

@@ -86,13 +86,27 @@ def message
       @message || self.class.name
     end
 
+    def inspect
+      "#{message}: #{body}"
+    end
+
+    def to_s
+      inspect
+    end
+  end
+
+  # We will a create an exception for each status code, see http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html
+  module Exceptions
+    # Map http status codes to the corresponding exception class
+    EXCEPTIONS_MAP = {}
   end
 
   STATUSES.each_pair do |code, message|
     klass = Class.new(Exception) do
       send(:define_method, :message) {"#{code ? "#{code} " : ''}#{message}"}
     end
 
-    const_set message.delete(' \-\''), klass
+    klass_constant = const_set message.delete(' \-\''), klass
+    Exceptions::EXCEPTIONS_MAP[code] = klass_constant
   end
 end

lib/blanket/wrapper.rb

@@ -67,9 +67,12 @@ def request(method, id=nil, options={})
         headers: headers
       }.reject { |k, v| v.nil? || v.empty? })
 
-      body = (response.respond_to? :body) ? response.body : nil
-
-      (body.is_a? Array) ? body.map(Response.new) : Response.new(body)
+      if response.code <= 400
+        body = (response.respond_to? :body) ? response.body : nil
+        (body.is_a? Array) ? body.map(Response.new) : Response.new(body)
+      else
+        raise Blanket::Exceptions::EXCEPTIONS_MAP[response.code].new(response)
+      end
     end
 
     def merged_headers(headers)

spec/blanket/wrapper_spec.rb

@@ -7,11 +7,9 @@
   end
 
   describe 'Making Requests' do
-    before :each do
-      allow(HTTParty).to receive(:get)
-    end
-
     it 'resets after performing a request' do
+      allow(HTTParty).to receive(:get) { StubbedResponse.new }
+
       api.users.get()
       api.videos.get()
 
@@ -20,19 +18,40 @@
 
     describe "Response" do
       before :each do
-        stub_request(:get, "http://api.example.org/users").to_return(:body => '{"title": "Something"}')
+        stub_request(:get, "http://api.example.org/users")
+        .to_return(:body => '{"title": "Something"}')
       end
 
       let :response do
-        api.users.get()
+        api.users.get
       end
 
       it "returns a Blanket::Response instance" do
         expect(response).to be_kind_of(Blanket::Response)
       end
     end
 
+    describe "Exceptions" do
+      let :api do
+        Blanket::wrap("http://api.example.org")
+      end
+
+      describe "500" do
+        before :each do
+          stub_request(:get, "http://api.example.org/users").to_return(:status => 500, :body => "You've been met with a terrible fate, haven't you?")
+        end
+
+        it "raises a Blanket::InternalServerError exception" do
+          expect { api.users.get }.to raise_exception(Blanket::InternalServerError)
+        end
+      end
+    end
+
     describe 'Resource identification' do
+      before do
+        allow(HTTParty).to receive(:get) { StubbedResponse.new }
+      end
+
       context 'When using a resource method' do
         it 'allows identifying a resource' do
           api.users(55).get()
@@ -57,6 +76,10 @@
     end
 
     describe 'Headers' do
+      before :each do
+        allow(HTTParty).to receive(:get) { StubbedResponse.new }
+      end
+
       it 'allows sending headers in a request' do
         api.users(55).get(headers: {foo: 'bar'})
 
@@ -72,6 +95,10 @@
     end
 
     describe 'Parameters' do
+      before :each do
+        allow(HTTParty).to receive(:get) { StubbedResponse.new }
+      end
+
       it 'allows sending parameters in a request' do
         api.users(55).get(params: {foo: 'bar'})
 
@@ -80,7 +107,11 @@
     end
 
     describe 'URL Extension' do
-      it 'allows setting an extension for a request', :wip => true do
+      before :each do
+        allow(HTTParty).to receive(:get) { StubbedResponse.new }
+      end
+
+      it 'allows setting an extension for a request' do
         users_endpoint = api.users(55)
         users_endpoint.extension = :json
         users_endpoint.get
@@ -98,8 +129,8 @@
   end
 
   describe '#get' do
-    before :each do
-      allow(HTTParty).to receive(:get)
+    before do
+      allow(HTTParty).to receive(:get) { StubbedResponse.new }
     end
 
     it 'GETs a resource' do
@@ -110,8 +141,8 @@
   end
 
   describe '#post' do
-    before :each do
-      allow(HTTParty).to receive(:post)
+    before do
+      allow(HTTParty).to receive(:post) { StubbedResponse.new }
     end
 
     it 'POSTs a resource' do
@@ -122,8 +153,8 @@
   end
 
   describe '#put' do
-    before :each do
-      allow(HTTParty).to receive(:put)
+    before do
+      allow(HTTParty).to receive(:put) { StubbedResponse.new }
     end
 
     it 'PUTs a resource' do
@@ -134,8 +165,8 @@
   end
 
   describe '#patch' do
-    before :each do
-      allow(HTTParty).to receive(:patch)
+    before do
+      allow(HTTParty).to receive(:patch) { StubbedResponse.new }
     end
 
     it 'PATCHes a resource' do
@@ -146,8 +177,8 @@
   end
 
   describe '#delete' do
-    before :each do
-      allow(HTTParty).to receive(:delete)
+    before do
+      allow(HTTParty).to receive(:delete) { StubbedResponse.new }
     end
 
     it 'DELETEs a resource' do

spec/spec_helper.rb

@@ -4,6 +4,12 @@
 require 'coveralls'
 Coveralls.wear!
 
+class StubbedResponse
+  def code
+    200
+  end
+end
+
 require 'pry'
 require 'webmock/rspec'
 require 'blanket'