Optimise getting the pipeline status of commitsci-pipeline-status-query

This adds an optimised way of getting the latest pipeline status for a
list of Commit objects (or just a single one).

3 files changed, 152 insertions, 40 deletions

diff --git a/spec/models/ci/pipeline_spec.rb b/spec/models/ci/pipeline_spec.rb
index 2c9e7013b77..b89b0e555d9 100644
--- a/spec/models/ci/pipeline_spec.rb
+++ b/spec/models/ci/pipeline_spec.rb
@@ -625,38 +625,29 @@ describe Ci::Pipeline, :mailer do
 
   shared_context 'with some outdated pipelines' do
     before do
-      create_pipeline(:canceled, 'ref', 'A')
-      create_pipeline(:success, 'ref', 'A')
-      create_pipeline(:failed, 'ref', 'B')
-      create_pipeline(:skipped, 'feature', 'C')
+      create_pipeline(:canceled, 'ref', 'A', project)
+      create_pipeline(:success, 'ref', 'A', project)
+      create_pipeline(:failed, 'ref', 'B', project)
+      create_pipeline(:skipped, 'feature', 'C', project)
     end
 
-    def create_pipeline(status, ref, sha)
-      create(:ci_empty_pipeline, status: status, ref: ref, sha: sha)
+    def create_pipeline(status, ref, sha, project)
+      create(
+        :ci_empty_pipeline,
+        status: status,
+        ref: ref,
+        sha: sha,
+        project: project
+      )
     end
   end
 
-  describe '.latest' do
+  describe '.newest_first' do
     include_context 'with some outdated pipelines'
 
-    context 'when no ref is specified' do
-      let(:pipelines) { described_class.latest.all }
-
-      it 'returns the latest pipeline for the same ref and different sha' do
-        expect(pipelines.map(&:sha)).to contain_exactly('A', 'B', 'C')
-        expect(pipelines.map(&:status))
-          .to contain_exactly('success', 'failed', 'skipped')
-      end
-    end
-
-    context 'when ref is specified' do
-      let(:pipelines) { described_class.latest('ref').all }
-
-      it 'returns the latest pipeline for ref and different sha' do
-        expect(pipelines.map(&:sha)).to contain_exactly('A', 'B')
-        expect(pipelines.map(&:status))
-          .to contain_exactly('success', 'failed')
-      end
+    it 'returns the pipelines from new to old' do
+      expect(described_class.newest_first.pluck(:status))
+        .to eq(%w[skipped failed success canceled])
     end
   end
 
@@ -664,20 +655,14 @@ describe Ci::Pipeline, :mailer do
     include_context 'with some outdated pipelines'
 
     context 'when no ref is specified' do
-      let(:latest_status) { described_class.latest_status }
-
-      it 'returns the latest status for the same ref and different sha' do
-        expect(latest_status).to eq(described_class.latest.status)
-        expect(latest_status).to eq('failed')
+      it 'returns the status of the latest pipeline' do
+        expect(described_class.latest_status).to eq('skipped')
       end
     end
 
     context 'when ref is specified' do
-      let(:latest_status) { described_class.latest_status('ref') }
-
-      it 'returns the latest status for ref and different sha' do
-        expect(latest_status).to eq(described_class.latest_status('ref'))
-        expect(latest_status).to eq('failed')
+      it 'returns the status of the latest pipeline for the given ref' do
+        expect(described_class.latest_status('ref')).to eq('failed')
       end
     end
   end
@@ -686,7 +671,7 @@ describe Ci::Pipeline, :mailer do
     include_context 'with some outdated pipelines'
 
     let!(:latest_successful_pipeline) do
-      create_pipeline(:success, 'ref', 'D')
+      create_pipeline(:success, 'ref', 'D', project)
     end
 
     it 'returns the latest successful pipeline' do
@@ -698,8 +683,13 @@ describe Ci::Pipeline, :mailer do
   describe '.latest_successful_for_refs' do
     include_context 'with some outdated pipelines'
 
-    let!(:latest_successful_pipeline1) { create_pipeline(:success, 'ref1', 'D') }
-    let!(:latest_successful_pipeline2) { create_pipeline(:success, 'ref2', 'D') }
+    let!(:latest_successful_pipeline1) do
+      create_pipeline(:success, 'ref1', 'D', project)
+    end
+
+    let!(:latest_successful_pipeline2) do
+      create_pipeline(:success, 'ref2', 'D', project)
+    end
 
     it 'returns the latest successful pipeline for both refs' do
       refs = %w(ref1 ref2 ref3)
@@ -708,6 +698,62 @@ describe Ci::Pipeline, :mailer do
     end
   end
 
+  describe '.latest_status_per_commit' do
+    let(:project) { create(:project) }
+
+    before do
+      pairs = [
+        %w[success ref1 123],
+        %w[manual master 123],
+        %w[failed ref 456]
+      ]
+
+      pairs.each do |(status, ref, sha)|
+        create(
+          :ci_empty_pipeline,
+          status: status,
+          ref: ref,
+          sha: sha,
+          project: project
+        )
+      end
+    end
+
+    context 'without a ref' do
+      it 'returns a Hash containing the latest status per commit for all refs' do
+        expect(described_class.latest_status_per_commit(%w[123 456]))
+          .to eq({ '123' => 'manual', '456' => 'failed' })
+      end
+
+      it 'only includes the status of the given commit SHAs' do
+        expect(described_class.latest_status_per_commit(%w[123]))
+          .to eq({ '123' => 'manual' })
+      end
+
+      context 'when there are two pipelines for a ref and SHA' do
+        it 'returns the status of the latest pipeline' do
+          create(
+            :ci_empty_pipeline,
+            status: 'failed',
+            ref: 'master',
+            sha: '123',
+            project: project
+          )
+
+          expect(described_class.latest_status_per_commit(%w[123]))
+            .to eq({ '123' => 'failed' })
+        end
+      end
+    end
+
+    context 'with a ref' do
+      it 'only includes the pipelines for the given ref' do
+        expect(described_class.latest_status_per_commit(%w[123 456], 'master'))
+          .to eq({ '123' => 'manual' })
+      end
+    end
+  end
+
   describe '.internal_sources' do
     subject { described_class.internal_sources }
 
diff --git a/spec/models/commit_collection_spec.rb b/spec/models/commit_collection_spec.rb
new file mode 100644
index 00000000000..066fe7d154e
--- /dev/null
+++ b/spec/models/commit_collection_spec.rb
@@ -0,0 +1,59 @@
+require 'spec_helper'
+
+describe CommitCollection do
+  let(:project) { create(:project, :repository) }
+  let(:commit) { project.commit }
+
+  describe '#each' do
+    it 'yields every commit' do
+      collection = described_class.new(project, [commit])
+
+      expect { |b| collection.each(&b) }.to yield_with_args(commit)
+    end
+  end
+
+  describe '#with_pipeline_status' do
+    it 'sets the pipeline status for every commit so no additional queries are necessary' do
+      create(
+        :ci_empty_pipeline,
+        ref: 'master',
+        sha: commit.id,
+        status: 'success',
+        project: project
+      )
+
+      collection = described_class.new(project, [commit])
+      collection.with_pipeline_status
+
+      recorder = ActiveRecord::QueryRecorder.new do
+        expect(commit.status).to eq('success')
+      end
+
+      expect(recorder.count).to be_zero
+    end
+  end
+
+  describe '#respond_to_missing?' do
+    it 'returns true when the underlying Array responds to the message' do
+      collection = described_class.new(project, [])
+
+      expect(collection.respond_to?(:last)).to eq(true)
+    end
+
+    it 'returns false when the underlying Array does not respond to the message' do
+      collection = described_class.new(project, [])
+
+      expect(collection.respond_to?(:foo)).to eq(false)
+    end
+  end
+
+  describe '#method_missing' do
+    it 'delegates undefined methods to the underlying Array' do
+      collection = described_class.new(project, [commit])
+
+      expect(collection.length).to eq(1)
+      expect(collection.last).to eq(commit)
+      expect(collection).not_to be_empty
+    end
+  end
+end
diff --git a/spec/models/commit_spec.rb b/spec/models/commit_spec.rb
index e3cfa149e3a..d18a5c9dfa6 100644
--- a/spec/models/commit_spec.rb
+++ b/spec/models/commit_spec.rb
@@ -351,12 +351,19 @@ eos
       end
 
       it 'gives compound status from latest pipelines if ref is nil' do
-        expect(commit.status(nil)).to eq(Ci::Pipeline.latest_status)
-        expect(commit.status(nil)).to eq('failed')
+        expect(commit.status(nil)).to eq(pipeline_from_fix.status)
       end
     end
   end
 
+  describe '#set_status_for_ref' do
+    it 'sets the status for a given reference' do
+      commit.set_status_for_ref('master', 'failed')
+
+      expect(commit.status('master')).to eq('failed')
+    end
+  end
+
   describe '#participants' do
     let(:user1) { build(:user) }
     let(:user2) { build(:user) }