From 69ceb27faa4ee9cddffc109f8df21174fbabbd2b Mon Sep 17 00:00:00 2001
From: Nick LaMuro <nicklamuro@gmail.com>
Date: Mon, 13 Jan 2020 18:14:40 -0600
Subject: [PATCH] [Branch] Add build failure concept

Use the Branch record to keep track of build failures that we find when
polling the Travis API.  The main purpose is to avoid spamming gitter
with extra notifications, but also can be used to identify that a branch
has previously been broken and now has been fixed.

Makes sense to also notify on the passing cases so others aren't taking
the time to investigate a failure when this has already been
investigated/fixed by another.
---
 app/models/branch.rb                          | 33 +++++++++++++++++++
 ...0200109223351_add_branch_build_failures.rb |  6 ++++
 db/schema.rb                                  |  4 ++-
 3 files changed, 42 insertions(+), 1 deletion(-)
 create mode 100644 db/migrate/20200109223351_add_branch_build_failures.rb

diff --git a/app/models/branch.rb b/app/models/branch.rb
index 976ab852..577e6b26 100644
--- a/app/models/branch.rb
+++ b/app/models/branch.rb
@@ -99,4 +99,37 @@ def fq_branch_name
   def git_service
     GitService::Branch.new(self)
   end
+
+  # Branch Failure
+
+  def notify_of_failure
+    if passing?
+      BuildFailureNotifier.new(self).report_passing
+      update(:last_build_failure_notified_at => nil, :travis_build_failure_id => nil)
+    elsif should_notify_of_failure?
+      update(:last_build_failure_notified_at => Time.zone.now)
+
+      BuildFailureNotifier.new(self).post_failure
+    end
+  end
+
+  def previously_failing?
+    !!travis_build_failure_id
+  end
+
+  def should_notify_of_failure?
+    last_build_failure_notified_at.nil? || last_build_failure_notified_at < 1.day.ago
+  end
+
+  # If we have reported a failure before and the branch is now green.
+  #
+  # The other advantage of checking `last_build_failure_notified_at.nil?` here
+  # is that we save a Travis API call, since we shouldn't be creating
+  # BuildFailure records without having found a build failure elsewhere (e.g.
+  # TravisBranchMonitor).
+  #
+  # New records will short circut before hitting `Travis::Repository.find`.
+  def passing?
+    !last_build_failure_notified_at.nil? && Travis::Repository.find(repo.name).branch(name).green?
+  end
 end
diff --git a/db/migrate/20200109223351_add_branch_build_failures.rb b/db/migrate/20200109223351_add_branch_build_failures.rb
new file mode 100644
index 00000000..1d1d5927
--- /dev/null
+++ b/db/migrate/20200109223351_add_branch_build_failures.rb
@@ -0,0 +1,6 @@
+class AddBranchBuildFailures < ActiveRecord::Migration[5.2]
+  def change
+    add_column :branches, :travis_build_failure_id, :integer
+    add_column :branches, :last_build_failure_notified_at, :datetime
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 1294151d..78ae5a11 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2017_10_06_050814) do
+ActiveRecord::Schema.define(version: 2020_01_09_223351) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -44,6 +44,8 @@
     t.string "merge_target"
     t.string "pr_title"
     t.integer "linter_offense_count"
+    t.integer "travis_build_failure_id"
+    t.datetime "last_build_failure_notified_at"
     t.index ["repo_id"], name: "index_branches_on_repo_id"
   end