Add Graphlient::Errors::ConnectionFailedError

CHANGELOG.md

@@ -1,5 +1,6 @@
 ### 0.3.7 (Next)
 * Your contribution here.
+* [#68](https://github.com/ashkan18/graphlient/pull/68): Add `Graphlient::Errors::ConnectionFailedError` - [@neroleung](https://github.com/neroleung).
 
 ### 0.3.6 (07/23/2019)
 

README.md

@@ -126,6 +126,7 @@ Unlike graphql-client, Graphlient will always raise an exception unless the quer
 * [Graphlient::Errors::ServerError](lib/graphlient/errors/server_error.rb): all transport errors raised by HTTP Adapters. You can access `inner_exception`, `status_code` and `response` on these errors to get more details on what went wrong
 * [Graphlient::Errors::FaradayServerError](lib/graphlient/errors/faraday_server_error.rb): this inherits from `ServerError` ☝️, we recommend using `ServerError` to rescue these
 * [Graphlient::Errors::HttpServerError](lib/graphlient/errors/http_server_error.rb): this inherits from `ServerError` ☝️, we recommend using `ServerError` to rescue these
+* [Graphlient::Errors::ConnectionFailedError](lib/graphlient/errors/connection_failed_error.rb): this inherits from `ServerError` ☝️, we recommend using `ServerError` to rescue these
 
 
 All errors inherit from `Graphlient::Errors::Error` if you need to handle them in bulk.

UPGRADING.md

@@ -0,0 +1,12 @@
+Upgrading Graphlient
+===========================
+
+### Upgrading to >= 0.3.7
+
+#### Changes in error handling of connection refused error
+
+Prior to 0.3.7, Graphlient would return `NoMethodError: undefined method []' for nil:NilClass` error if connection is
+refused/failed when connecting to a remote host. After 0.3.7, Graphlient will return a new 
+`Graphlient::Errors::ConnectionFailedError` instead.
+
+See [#68](https://github.com/ashkan18/graphlient/pull/68) for more information.

lib/graphlient/adapters/http/faraday_adapter.rb

@@ -15,6 +15,8 @@ def execute(document:, operation_name:, variables:, context:)
             }.to_json
           end
           response.body
+        rescue Faraday::ConnectionFailed => e
+          raise Graphlient::Errors::ConnectionFailedError, e
         rescue Faraday::ClientError => e
           raise Graphlient::Errors::FaradayServerError, e
         end

lib/graphlient/errors.rb

@@ -5,3 +5,4 @@
 require_relative 'errors/execution_error'
 require_relative 'errors/faraday_server_error'
 require_relative 'errors/http_server_error'
+require_relative 'errors/connection_failed_error'

lib/graphlient/errors/connection_failed_error.rb

@@ -0,0 +1,6 @@
+module Graphlient
+  module Errors
+    class ConnectionFailedError < ServerError
+    end
+  end
+end

spec/graphlient/adapters/http/faraday_adapter_spec.rb

@@ -57,4 +57,25 @@
       expect(client.schema).to be_a Graphlient::Schema
     end
   end
+
+  context 'Failed to open TCP connection error' do
+    let(:url) { 'http://example.com/graphql' }
+    let(:client) { Graphlient::Client.new(url) }
+    let(:error_message) do
+      'Failed to open TCP connection to localhost:3000 (Connection refused - connect(2) for "localhost" port 3000)'
+    end
+
+    before do
+      wrapped_error = Errno::ECONNREFUSED.new(error_message)
+      error = Faraday::ConnectionFailed.new(wrapped_error)
+
+      stub_request(:post, url).to_raise(error)
+    end
+
+    specify do
+      expected_error_message = "Connection refused - #{error_message}"
+
+      expect { client.schema }.to raise_error(Graphlient::Errors::ConnectionFailedError, expected_error_message)
+    end
+  end
 end