From f81852f14bc461806ec82b9c83a73273098fc924 Mon Sep 17 00:00:00 2001
From: Jason Garber <jason@sixtwothree.org>
Date: Mon, 25 Jun 2018 20:48:07 -0400
Subject: [PATCH] Add error class and rescue/raise common errors

---
 README.md                            | 16 ++++++++--------
 lib/webmention/endpoint.rb           |  1 +
 lib/webmention/endpoint/discover.rb  | 10 ++++++++++
 lib/webmention/endpoint/error.rb     | 15 +++++++++++++++
 lib/webmention/endpoint/version.rb   |  2 +-
 spec/lib/webmention/endpoint_spec.rb |  8 +++++++-
 6 files changed, 42 insertions(+), 10 deletions(-)
 create mode 100644 lib/webmention/endpoint/error.rb

diff --git a/README.md b/README.md
index 36a61be..4b8366e 100644
--- a/README.md
+++ b/README.md
@@ -80,17 +80,17 @@ puts discoverer.response # returns HTTP::Response
 
 ### Exception Handling
 
-There are several exceptions that may be raised by webmention-endpoint-ruby's underlying dependencies:
+There are several exceptions that may be raised by webmention-endpoint-ruby's underlying dependencies. These errors are raised as subclasses of `Webmention::Endpoint::Error` (which itself is a subclass of `StandardError`).
 
-- `Addressable::URI::InvalidURIError`
-- `HTTP::ConnectionError`
-- `HTTP::TimeoutError`
-- `HTTP::Redirector::TooManyRedirectsError`
+From [sporkmonger/addressable](/~https://github.com/sporkmonger/addressable):
 
-You'll want to make sure your code gracefully handles these exceptions. For more on each of these exceptions, see:
+- `Webmention::Endpoint::InvalidURIError`
 
-- [sporkmonger/addressable](/~https://github.com/sporkmonger/addressable) – Source code for the Addressable Ruby gem
-- [httprb/http](/~https://github.com/httprb/http) – Source code for the HTTP Ruby gem
+From [httprb/http](/~https://github.com/httprb/http):
+
+- `Webmention::Endpoint::ConnectionError`
+- `Webmention::Endpoint::TimeoutError`
+- `Webmention::Endpoint::TooManyRedirectsError`
 
 ## Contributing
 
diff --git a/lib/webmention/endpoint.rb b/lib/webmention/endpoint.rb
index c9781f4..a5679f2 100644
--- a/lib/webmention/endpoint.rb
+++ b/lib/webmention/endpoint.rb
@@ -3,6 +3,7 @@
 require 'nokogiri'
 
 require 'webmention/endpoint/version'
+require 'webmention/endpoint/error'
 require 'webmention/endpoint/discover'
 
 module Webmention
diff --git a/lib/webmention/endpoint/discover.rb b/lib/webmention/endpoint/discover.rb
index 4b3893d..4491bb6 100644
--- a/lib/webmention/endpoint/discover.rb
+++ b/lib/webmention/endpoint/discover.rb
@@ -25,6 +25,8 @@ def initialize(url)
 
         @url = url
         @uri = Addressable::URI.parse(url)
+      rescue Addressable::URI::InvalidURIError => error
+        raise InvalidURIError, error
       end
 
       def endpoint
@@ -36,6 +38,12 @@ def response
           connect: 10,
           read: 10
         ).get(uri)
+      rescue HTTP::ConnectionError => error
+        raise ConnectionError, error
+      rescue HTTP::TimeoutError => error
+        raise TimeoutError, error
+      rescue HTTP::Redirector::TooManyRedirectsError => error
+        raise TooManyRedirectsError, error
       end
 
       private
@@ -49,6 +57,8 @@ def absolutize(base:, relative:)
         return relative if relative_uri.absolute?
 
         (base_uri + relative_uri).to_s
+      rescue Addressable::URI::InvalidURIError => error
+        raise InvalidURIError, error
       end
 
       def endpoint_from_body
diff --git a/lib/webmention/endpoint/error.rb b/lib/webmention/endpoint/error.rb
new file mode 100644
index 0000000..19636af
--- /dev/null
+++ b/lib/webmention/endpoint/error.rb
@@ -0,0 +1,15 @@
+module Webmention
+  module Endpoint
+    class Error < StandardError; end
+
+    class ArgumentError < Error; end
+
+    class ConnectionError < Error; end
+
+    class InvalidURIError < Error; end
+
+    class TimeoutError < Error; end
+
+    class TooManyRedirectsError < Error; end
+  end
+end
diff --git a/lib/webmention/endpoint/version.rb b/lib/webmention/endpoint/version.rb
index 31198ef..9a92b08 100644
--- a/lib/webmention/endpoint/version.rb
+++ b/lib/webmention/endpoint/version.rb
@@ -1,5 +1,5 @@
 module Webmention
   module Endpoint
-    VERSION = '0.1.0'.freeze
+    VERSION = '0.2.0'.freeze
   end
 end
diff --git a/spec/lib/webmention/endpoint_spec.rb b/spec/lib/webmention/endpoint_spec.rb
index 76c2eb9..fa84010 100644
--- a/spec/lib/webmention/endpoint_spec.rb
+++ b/spec/lib/webmention/endpoint_spec.rb
@@ -8,7 +8,13 @@
       let(:message) { 'url must be a String (given NilClass)' }
 
       it 'raises an ArgumentError' do
-        expect { described_class.discover(nil) }.to raise_error(ArgumentError, message)
+        expect { described_class.discover(nil) }.to raise_error(Webmention::Endpoint::ArgumentError, message)
+      end
+    end
+
+    context 'when given an invalid URL' do
+      it 'raises an InvalidURIError' do
+        expect { described_class.discover('http:') }.to raise_error(Webmention::Endpoint::InvalidURIError)
       end
     end