[GOG-150] Adding pre-condition check for uncached deploy spec (#26)

* Adding pre-condition check for uncached deploy spec

* Added commit onto DeploySpec stack

* Added DeploySpec repo

* Added check_deploy_spec stack

* Adding test to make sure trigger_continuous_delivery returns when cached_deploy_spec config is empty

* removing whitespace

* Removed multiline for spec config. Added newline at eof

* Removing deletion of canary tasks from deploy spec test

* Breaking down trigger_continuous_delivery fn. Removed duplicated env declaration

* can_trigger_continuous_delivery

* Further refactored trigger_continuous_delivery

* Making delivery condition fns private

app/models/shipit/stack.rb

@@ -62,17 +62,6 @@ def env
       }
     end
 
-    def env
-      {
-        'ENVIRONMENT' => environment,
-        'LAST_DEPLOYED_SHA' => last_deployed_commit.sha,
-        'GITHUB_REPO_OWNER' => repository.owner,
-        'GITHUB_REPO_NAME' => repository.name,
-        'DEPLOY_URL' => deploy_url,
-        'BRANCH' => branch,
-      }
-    end
-
     def repository
       super || build_repository
     end
@@ -182,16 +171,8 @@ def continuous_delivery_delayed!
     def trigger_continuous_delivery
       commit = next_commit_to_deploy
 
-      if !deployable? || deployed_too_recently? || commit.nil? || commit.deployed?
-        continuous_delivery_resumed!
-        return
-      end
-
-      if commit.deploy_failed? || (checks? && !EphemeralCommitChecks.new(commit).run.success?) ||
-         commit.recently_pushed?
-        continuous_delivery_delayed!
-        return
-      end
+      return continuous_delivery_resumed! if should_resume_continuous_delivery?(commit)
+      return continuous_delivery_delayed! if should_delay_continuous_delivery?(commit)
 
       begin
         trigger_deploy(commit, Shipit.user, env: cached_deploy_spec.default_deploy_env)
@@ -626,5 +607,19 @@ def emit_merge_status_hooks
     def ci_enabled_cache_key
       "stacks:#{id}:ci_enabled"
     end
+
+    def should_delay_continuous_delivery?(commit)
+      commit.deploy_failed? ||
+        (checks? && !EphemeralCommitChecks.new(commit).run.success?) ||
+        commit.recently_pushed? ||
+        cached_deploy_spec.config.empty?
+    end
+
+    def should_resume_continuous_delivery?(commit)
+      !deployable? ||
+        deployed_too_recently? ||
+        commit.nil? ||
+        commit.deployed?
+    end
   end
 end

test/fixtures/shipit/commits.yml

@@ -373,3 +373,17 @@ task_no_commits:
   additions: 420
   deletions: 342
   updated_at: <%= 8.days.ago.to_s(:db) %>
+
+check_deploy_spec_first:
+  id: 701
+  sha: 547578b362bf2b4df5903e1c7960929361c3435a
+  message: "Removing deploy spec"
+  stack: check_deploy_spec
+  author: walrus
+  committer: walrus
+  authored_at: <%= 4.days.ago.to_s(:db) %>
+  committed_at: <%= 3.days.ago.to_s(:db) %>
+  additions: 420
+  deletions: 342
+  updated_at: <%= 8.days.ago.to_s(:db) %>
+

test/fixtures/shipit/repositories.yml

@@ -18,6 +18,10 @@ check_runs:
   owner: shopify
   name: check_runs
 
+check_deploy_spec:
+  owner: shopify
+  name: check_deploy_spec
+
 rails:
   owner: rails
   name: rails

test/fixtures/shipit/stacks.yml

@@ -404,3 +404,16 @@ shipit_task_no_commits:
       }
     }
   updated_at: <%= 8.days.ago.to_s(:db) %>
+
+check_deploy_spec:
+  repository: check_deploy_spec
+  environment: production
+  branch: master
+  ignore_ci: true
+  merge_queue_enabled: true
+  tasks_count: 0
+  undeployed_commits_count: 1
+  continuous_deployment: true
+  cached_deploy_spec: "{}"
+  last_deployed_at: <%= 8.days.ago.to_s(:db) %>
+  updated_at: <%= 8.days.ago.to_s(:db) %>

test/models/stacks_test.rb

@@ -568,6 +568,21 @@ def self.deliver(event, stack, payload)
       end
     end
 
+    test "#trigger_continuous_delivery bails out if no DeploySpec has been cached" do
+      @stack = shipit_stacks(:check_deploy_spec)
+      config = @stack.cached_deploy_spec.config
+
+      assert_predicate @stack, :deployable?
+      refute_predicate @stack, :deployed_too_recently?
+      assert_empty(config, "DeploySpec was not empty")
+
+      assert_no_enqueued_jobs(only: Shipit::PerformTaskJob) do
+        assert_no_difference -> { Deploy.count } do
+          @stack.trigger_continuous_delivery
+        end
+      end
+    end
+
     test "#trigger_continuous_delivery enqueues deployment ref update job" do
       @stack = shipit_stacks(:shipit_canaries)
       shipit_tasks(:canaries_running).delete