From 46b65e554195daa74f70d2841435ad79db6e226d Mon Sep 17 00:00:00 2001
From: markgibbons <mark.gibbons@nordstrom.com>
Date: Mon, 28 Jan 2019 12:58:10 -0800
Subject: [PATCH] Add support to handle 429 responses from a rate limited
 gitlab instance

Gitlab may respond with a 429 error and a message of 'Retry later'.  The
response body in this case has content-type 'text/plain'. This change
adds support for 429 errors and processes the body of responses with
content formated as 'text/plain'.

Add tests for the changes to Gitlab:Error:ResponseError.build_error_message
---
 .rubocop.yml              |  3 +++
 lib/gitlab/error.rb       | 16 +++++++++++++++-
 lib/gitlab/request.rb     |  1 +
 spec/gitlab/error_spec.rb | 18 ++++++++++++++++++
 4 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/.rubocop.yml b/.rubocop.yml
index cbdd2965b..f976bda6c 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -14,6 +14,9 @@ Metrics/BlockLength:
   Exclude:
     - 'spec/**/*'
 
+Metrics/CyclomaticComplexity:
+  Max: 15
+
 Style/Documentation:
   Enabled: false
 
diff --git a/lib/gitlab/error.rb b/lib/gitlab/error.rb
index 6fc048db4..d6baae611 100644
--- a/lib/gitlab/error.rb
+++ b/lib/gitlab/error.rb
@@ -40,7 +40,7 @@ def response_message
       #
       # @return [String]
       def build_error_message
-        parsed_response = @response.parsed_response
+        parsed_response = classified_response
         message = check_error_keys(parsed_response)
         "Server responded with code #{@response.code}, message: " \
         "#{handle_message(message)}. " \
@@ -54,6 +54,17 @@ def check_error_keys(resp)
         key ? resp.send(key) : resp
       end
 
+      # Parse the body based on the classification of the body content type
+      #
+      # @return parsed response
+      def classified_response
+        if @response.respond_to?('headers')
+          @response.headers['content-type'] == 'text/plain' ? { message: @response.to_s } : @response.parsed_response
+        else
+          @response.parsed_response
+        end
+      end
+
       # Handle error response message in case of nested hashes
       def handle_message(message)
         case message
@@ -90,6 +101,9 @@ class Conflict < ResponseError; end
     # Raised when API endpoint returns the HTTP status code 422.
     class Unprocessable < ResponseError; end
 
+    # Raised when API endpoint returns the HTTP status code 429.
+    class TooManyRequests < ResponseError; end
+
     # Raised when API endpoint returns the HTTP status code 500.
     class InternalServerError < ResponseError; end
 
diff --git a/lib/gitlab/request.rb b/lib/gitlab/request.rb
index cb7a59a23..be8f84d77 100644
--- a/lib/gitlab/request.rb
+++ b/lib/gitlab/request.rb
@@ -58,6 +58,7 @@ def validate(response)
                     when 405 then Error::MethodNotAllowed
                     when 409 then Error::Conflict
                     when 422 then Error::Unprocessable
+                    when 429 then Error::TooManyRequests
                     when 500 then Error::InternalServerError
                     when 502 then Error::BadGateway
                     when 503 then Error::ServiceUnavailable
diff --git a/spec/gitlab/error_spec.rb b/spec/gitlab/error_spec.rb
index 26e3a524d..f5f1538a9 100644
--- a/spec/gitlab/error_spec.rb
+++ b/spec/gitlab/error_spec.rb
@@ -34,3 +34,21 @@
     end
   end
 end
+
+describe Gitlab::Error::ResponseError do
+  before do
+    @request_double = double('request', base_uri: 'https://gitlab.com/api/v3', path: '/foo', options: {})
+  end
+
+  it 'Builds an error message from text' do
+    headers = { 'content-type' => 'text/plain' }
+    response_double = double('response', body: 'Retry later', to_s: 'Retry text', parsed_response: { message: 'Retry hash' }, code: 429, options: {}, headers: headers, request: @request_double)
+    expect(described_class.new(response_double).send(:build_error_message)).to match(/Retry text/)
+  end
+
+  it 'Builds an error message from parsed json' do
+    headers = { 'content-type' => 'application/json' }
+    response_double = double('response', body: 'Retry later', to_s: 'Retry text', parsed_response: { message: 'Retry hash' }, code: 429, options: {}, headers: headers, request: @request_double)
+    expect(described_class.new(response_double).send(:build_error_message)).to match(/Retry hash/)
+  end
+end