Look for code nav data in the latest commits

If the data doesn't exist for the requested commit, the data
from the latest commits may work as well

lib/gitlab/code_navigation_path.rb

@@ -6,6 +6,7 @@ module Gitlab
     include Gitlab::Routing
 
     CODE_NAVIGATION_JOB_NAME = 'code_navigation'
+    LATEST_COMMITS_LIMIT = 10
 
     def initialize(project, commit_sha)
       @project = project
@@ -25,8 +26,11 @@ module Gitlab
 
     def build
       strong_memoize(:build) do
+        latest_commits_shas =
+          project.repository.commits(commit_sha, limit: LATEST_COMMITS_LIMIT).map(&:sha)
+
         artifact = ::Ci::JobArtifact
-          .for_sha(commit_sha, project.id)
+          .for_sha(latest_commits_shas, project.id)
           .for_job_name(CODE_NAVIGATION_JOB_NAME)
           .last
 

spec/lib/gitlab/code_navigation_path_spec.rb

@@ -4,26 +4,38 @@ require 'spec_helper'
 
 describe Gitlab::CodeNavigationPath do
   context 'when there is an artifact with code navigation data' do
-    let(:project) { create(:project, :repository) }
-    let(:sha) { project.commit.id }
-    let(:build_name) { Gitlab::CodeNavigationPath::CODE_NAVIGATION_JOB_NAME }
+    let_it_be(:project) { create(:project, :repository) }
+    let_it_be(:sha) { project.repository.commits('master', limit: 5).last.id }
+    let_it_be(:build_name) { Gitlab::CodeNavigationPath::CODE_NAVIGATION_JOB_NAME }
+    let_it_be(:pipeline) { create(:ci_pipeline, project: project, sha: sha) }
+    let_it_be(:job) { create(:ci_build, pipeline: pipeline, name: build_name) }
+    let_it_be(:artifact) { create(:ci_job_artifact, :lsif, job: job) }
+
+    let(:commit_sha) { sha }
     let(:path) { 'lib/app.rb' }
-    let!(:pipeline) { create(:ci_pipeline, project: project, sha: sha) }
-    let!(:job) { create(:ci_build, pipeline: pipeline, name: build_name) }
-    let!(:artifact) { create(:ci_job_artifact, :lsif, job: job) }
 
-    subject { described_class.new(project, sha).full_json_path_for(path) }
+    subject { described_class.new(project, commit_sha).full_json_path_for(path) }
 
-    it 'assigns code_navigation_build variable' do
+    context 'when a pipeline exist for a sha' do
+      it 'returns path to a file in the artifact' do
         expect(subject).to eq("/#{project.full_path}/-/jobs/#{job.id}/artifacts/raw/lsif/#{path}.json")
       end
+    end
+
+    context 'when a pipeline exist for the latest commits' do
+      let(:commit_sha) { project.commit.id }
+
+      it 'returns path to a file in the artifact' do
+        expect(subject).to eq("/#{project.full_path}/-/jobs/#{job.id}/artifacts/raw/lsif/#{path}.json")
+      end
+    end
 
     context 'when code_navigation feature is disabled' do
       before do
         stub_feature_flags(code_navigation: false)
       end
 
-      it 'does not assign code_navigation_build variable' do
+      it 'returns nil' do
         expect(subject).to be_nil
       end
     end