Parse build trace checksum provided in hexadecimal

GitLab Runner sends build trace CRC32 checksum in a hexadecimal format.
This commit converts hexadecimal number to decimal to make it possible
to verfiy checksum.

app/models/ci/build_pending_state.rb

@@ -9,4 +9,10 @@ class Ci::BuildPendingState < ApplicationRecord
   enum failure_reason: CommitStatus.failure_reasons
 
   validates :build, presence: true
+
+  def crc32
+    trace_checksum.try do |checksum|
+      checksum.to_s.split('crc32:').last.to_i(16)
+    end
+  end
 end

lib/gitlab/ci/trace/checksum.rb

@@ -24,17 +24,13 @@ module Gitlab
         end
 
         def valid?
-          return false unless state_crc32 > 0
+          return false unless state_crc32.present?
 
           state_crc32 == chunks_crc32
         end
 
         def state_crc32
-          strong_memoize(:crc32) do
-            build.pending_state&.trace_checksum.then do |checksum|
-              checksum.to_s.split('crc32:').last.to_i
-            end
-          end
+          strong_memoize(:crc32) { build.pending_state&.crc32 }
         end
 
         def chunks_crc32

spec/factories/ci/build_pending_states.rb

@@ -3,7 +3,7 @@
 FactoryBot.define do
   factory :ci_build_pending_state, class: 'Ci::BuildPendingState' do
     build factory: :ci_build
-    trace_checksum { 'crc32:12345678' }
+    trace_checksum { 'crc32:bc614e' }
     state { 'success' }
   end
 end

spec/lib/gitlab/ci/trace/checksum_spec.rb

@@ -9,7 +9,7 @@ RSpec.describe Gitlab::Ci::Trace::Checksum do
 
   context 'when build pending state exists' do
     before do
-      create(:ci_build_pending_state, build: build, trace_checksum: 'crc32:3564598592')
+      create(:ci_build_pending_state, build: build, trace_checksum: 'crc32:d4777540')
     end
 
     context 'when matching persisted trace chunks exist' do
@@ -70,8 +70,8 @@ RSpec.describe Gitlab::Ci::Trace::Checksum do
 
   context 'when build pending state is missing' do
     describe '#state_crc32' do
-      it 'returns zero' do
-        expect(subject.state_crc32).to be_zero
+      it 'returns nil' do
+        expect(subject.state_crc32).to be_nil
       end
     end
 

spec/models/ci/build_pending_state_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Ci::BuildPendingState do
+  describe '#crc32' do
+    context 'when checksum does not exist' do
+      let(:pending_state) do
+        build(:ci_build_pending_state, trace_checksum: nil)
+      end
+
+      it 'returns nil' do
+        expect(pending_state.crc32).to be_nil
+      end
+    end
+
+    context 'when checksum is in hexadecimal' do
+      let(:pending_state) do
+        build(:ci_build_pending_state, trace_checksum: 'crc32:75bcd15')
+      end
+
+      it 'returns decimal representation of the checksum' do
+        expect(pending_state.crc32).to eq 123456789
+      end
+    end
+  end
+end

spec/services/ci/update_build_state_service_spec.rb

@@ -125,7 +125,7 @@ RSpec.describe Ci::UpdateBuildStateService do
       end
 
       context 'when trace checksum is valid' do
-        let(:params) { { checksum: 'crc32:3984772369', state: 'success' } }
+        let(:params) { { checksum: 'crc32:ed82cd11', state: 'success' } }
 
         it 'does not increment invalid trace metric' do
           execute_with_stubbed_metrics!