Add build eraseable feature implementation

app/controllers/projects/builds_controller.rb

@@ -56,10 +56,10 @@ class Projects::BuildsController < Projects::ApplicationController
     render json: @build.to_json(only: [:status, :id, :sha, :coverage], methods: :sha)
   end
 
-  def destroy
-    @build.destroy
-    redirect_to namespace_project_builds_path(project.namespace, project),
-                notice: "Build ##{@build.id} has been sucessfully removed!"
+  def erase
+    @build.erase!
+    redirect_to namespace_project_build_path(project.namespace, project, @build),
+                notice: "Build ##{@build.id} has been sucessfully erased!"
   end
 
   private

app/models/ci/build/eraseable.rb

@@ -4,11 +4,26 @@ module Ci
       include ActiveSupport::Concern
 
       def erase!
-        raise NotImplementedError
+        raise StandardError, 'Build not eraseable!' unless eraseable?
+        remove_artifacts_file!
+        remove_artifacts_metadata!
+        erase_trace!
       end
 
-      def erased?
-        raise NotImpementedError
+      def eraseable?
+        artifacts_file.exists? || File.file?(path_to_trace)
+      end
+
+      def erase_url
+        if eraseable?
+          erase_namespace_project_build_path(project.namespace, project, self)
+        end
+      end
+
+      private
+
+      def erase_trace!
+        File.truncate(path_to_trace, 0) if File.file?(path_to_trace)
       end
     end
   end

app/views/projects/builds/show.html.haml

@@ -113,10 +113,11 @@
               - elsif @build.retry_url
                 = link_to "Retry", @build.retry_url, class: 'btn btn-sm btn-primary', method: :post
 
-              = link_to '', class: 'btn btn-sm btn-danger', method: :delete,
-                            data: { confirm: 'Are you sure you want to remove this?' } do
-                = icon('remove')
-                Remove
+              - if @build.eraseable?
+                = link_to @build.erase_url, class: 'btn btn-sm btn-warning', method: :put,
+                                            data: { confirm: 'Are you sure you want to erase this build?' } do
+                  = icon('eraser')
+                  Erase
 
         .clearfix
           - if @build.duration

config/routes.rb

@@ -617,6 +617,7 @@ Rails.application.routes.draw do
             get :status
             post :cancel
             post :retry
+            put :erase
           end
 
           resource :artifacts, only: [] do

spec/models/ci/build/eraseable_spec.rb

+require 'spec_helper'
+
+describe Ci::Build::Eraseable, models: true do
+  context 'build is not eraseable' do
+    let!(:build) { create(:ci_build) }
+
+    describe '#erase!' do
+      it { expect { build.erase! }.to raise_error(StandardError, /Build not eraseable!/ )}
+    end
+
+    describe '#eraseable?' do
+      subject { build.eraseable? }
+      it { is_expected.to eq false }
+    end
+
+    describe '#erase_url' do
+      subject { build.erase_url }
+      it { is_expected.to be_falsy }
+    end
+  end
+
+  context 'build is eraseable' do
+    let!(:build) { create(:ci_build_with_trace, :artifacts) }
+
+    describe '#erase!' do
+      before { build.erase! }
+
+      it 'should remove artifact file' do
+        expect(build.artifacts_file.exists?).to be_falsy
+      end
+
+      it 'should remove artifact metadata file' do
+        expect(build.artifacts_metadata.exists?).to be_falsy
+      end
+
+      it 'should erase build trace in trace file' do
+        expect(File.zero?(build.path_to_trace)).to eq true
+      end
+    end
+
+    describe '#eraseable?' do
+      subject { build.eraseable? }
+      it { is_expected.to eq true }
+    end
+
+    describe '#erase_url' do
+      subject { build.erase_url }
+      it { is_expected.to be_truthy }
+    end
+
+    context 'metadata and build trace are not available' do
+      let!(:build) { create(:ci_build, :artifacts) }
+      before { build.remove_artifacts_metadata! }
+
+      describe '#erase!' do
+        it 'should not raise error' do
+          expect { build.erase! }.to_not raise_error
+        end
+      end
+    end
+  end
+end