From 77ecafa978e8d2f1f91a4686ee31df3fb85870f5 Mon Sep 17 00:00:00 2001
From: Andrew Waage <andrew@retentionscience.com>
Date: Wed, 19 Oct 2016 14:30:43 -0700
Subject: [PATCH] using retriable gem

---
 github_changelog_generator.gemspec            |  2 +
 .../octo_fetcher.rb                           | 65 ++++++++++---------
 spec/unit/octo_fetcher_spec.rb                |  2 +-
 3 files changed, 36 insertions(+), 33 deletions(-)

diff --git a/github_changelog_generator.gemspec b/github_changelog_generator.gemspec
index c114b9c..ec22619 100644
--- a/github_changelog_generator.gemspec
+++ b/github_changelog_generator.gemspec
@@ -29,4 +29,6 @@ Gem::Specification.new do |spec|
   spec.add_runtime_dependency("octokit", ["~> 4.0"])
   spec.add_runtime_dependency("faraday-http-cache")
   spec.add_runtime_dependency("activesupport")
+  spec.add_runtime_dependency("retriable", ["~> 2.1"])
+
 end
diff --git a/lib/github_changelog_generator/octo_fetcher.rb b/lib/github_changelog_generator/octo_fetcher.rb
index ee82e07..a1f1f0f 100644
--- a/lib/github_changelog_generator/octo_fetcher.rb
+++ b/lib/github_changelog_generator/octo_fetcher.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+require 'retriable'
 module GitHubChangelogGenerator
   # A Fetcher responsible for all requests to GitHub and all basic manipulation with related data
   # (such as filtering, validating, e.t.c)
@@ -281,47 +282,47 @@ Make sure, that you push tags to remote repo via 'git push --tags'"
     #
     # @return [Object] returns exactly the same, what you put in the block, but wrap it with begin-rescue block
     def check_github_response
-      attempt = 1
-      begin
-        value = yield
-      rescue Octokit::Unauthorized => e
-        Helper.log.error e.message
-        sys_abort("Error: wrong GitHub token")
-      rescue Octokit::Forbidden => e
-        attempt += 1
-        sleep_time = exp_backoff(attempt)
-        Helper.log.warn("sleeping #{sleep_time} second")
-        sys_sleep(sleep_time)
-
-        Helper.log.warn e.message
-        Helper.log.warn GH_RATE_LIMIT_EXCEEDED_MSG
-        Helper.log.warn @client.rate_limit
-
-        if attempt >= MAX_FORBIDDEN_RETRIES
-          sys_abort("Exceeded retry limit")
-        else
-          retry
-        end
+      Retriable.retriable(retry_options) do
+        yield
       end
-      value
+
+    rescue Octokit::Forbidden => e
+      Helper.log.error("#{e.class}: #{e.message}")
+      sys_abort("Exceeded retry limit")
+    rescue Octokit::Unauthorized => e
+      Helper.log.error("#{e.class}: #{e.message}")
+      sys_abort("Error: wrong GitHub token")
     end
 
-    def sys_sleep(seconds)
-      sleep(seconds)
+    # Exponential backoff
+    def retry_options
+      {
+        :on            => [Octokit::Forbidden],
+        :tries         => MAX_FORBIDDEN_RETRIES,
+        :base_interval => sleep_base_interval,
+        :multiplier    => 1.0,
+        :rand_factor   => 0.0,
+        :on_retry      => retry_callback
+      }
+    end
+
+    def sleep_base_interval
+      1.0
+    end
+
+    def retry_callback
+      Proc.new do |exception, try, elapsed_time, next_interval|
+        Helper.log.warn("RETRY - #{exception.class}: '#{exception.message}'")
+        Helper.log.warn("#{try} tries in #{elapsed_time} seconds and #{next_interval} seconds until the next try")
+        Helper.log.warn GH_RATE_LIMIT_EXCEEDED_MSG
+        Helper.log.warn @client.rate_limit
+      end
     end
 
     def sys_abort(msg)
       abort(msg)
     end
 
-    # Returns the exponential backoff (seconds) for this attempt number
-    #
-    # @param [Integer] attempt the attempt number
-    # @return [Integer] Exponential backoff seconds
-    def exp_backoff(attempt)
-      (2**attempt - 1) / 2
-    end
-
     # Print specified line on the same string
     #
     # @param [String] log_string
diff --git a/spec/unit/octo_fetcher_spec.rb b/spec/unit/octo_fetcher_spec.rb
index 7a254b4..a4398b1 100644
--- a/spec/unit/octo_fetcher_spec.rb
+++ b/spec/unit/octo_fetcher_spec.rb
@@ -29,9 +29,9 @@ describe GitHubChangelogGenerator::OctoFetcher do
     context "when raises Octokit::Forbidden" do
       it "sleeps and retries and then aborts" do
         retry_limit = GitHubChangelogGenerator::OctoFetcher::MAX_FORBIDDEN_RETRIES - 1
+        allow(fetcher).to receive(:sleep_base_interval).and_return(0)
 
         expect(fetcher).to receive(:sys_abort).with("Exceeded retry limit")
-        expect(fetcher).to receive(:sys_sleep).exactly(retry_limit).times
         fetcher.send(:check_github_response) { raise(Octokit::Forbidden) }
       end
     end