Truncated CSV exports include count of issues included

app/mailers/emails/issues.rb

@@ -49,10 +49,11 @@ module Emails
       mail_answer_thread(issue, issue_thread_options(updated_by_user.id, recipient.id))
     end
 
-    def issues_csv_email(user, project, csv_data, issues_count, truncated = false)
+    def issues_csv_email(user, project, csv_data, export_status)
       @project = project
-      @issues_count = issues_count
-      @truncated = truncated
+      @issues_count = export_status.fetch(:rows_expected)
+      @written_count = export_status.fetch(:rows_written)
+      @truncated = export_status.fetch(:truncated)
 
       filename = "#{project.full_path.parameterize}_issues_#{Date.today.iso8601}.csv"
       attachments[filename] = { content: csv_data, mime_type: 'text/csv' }

app/services/issues/export_csv_service.rb

@@ -16,7 +16,7 @@ module Issues
     end
 
     def email(user, project)
-      Notify.issues_csv_email(user, project, csv_data, @issues.count, csv_builder.truncated?).deliver_now
+      Notify.issues_csv_email(user, project, csv_data, csv_builder.status).deliver_now
     end
 
     def csv_builder

app/views/notify/issues_csv_email.html.haml

 %span{ style: 'font-size:18px;'}
-  Your CSV export of #{ @issues_count } issues from project
+  Your CSV export of #{ @written_count } issues from project
   %a{ href: project_url(@project), style: "color:#3777b0;text-decoration:none;" }
     = @project.full_name
   has been added to this email as an attachment.
   - if @truncated
     %p
-      This attachment has been truncated due to exceeding the maximum attachment size. Consider re-exporting with a narrower selection of issues.
+      This attachment has been truncated to avoid exceeding a maximum allowed attachment size of 20MB. #{ @written_count } of #{ @issues_count } issues have been included. Consider re-exporting with a narrower selection of issues.

app/views/notify/issues_csv_email.text.erb

-Your CSV export of <%= @issues_count %> issues from project <%= @project.full_name %> ( <%= project_url(@project) %> ) has been added to this email as an attachment.
+Your CSV export of <%= @written_count %> issues from project <%= @project.full_name %> ( <%= project_url(@project) %> ) has been added to this email as an attachment.
 
 <% if @truncated %>
-This attachment has been truncated due to exceeding the maximum attachment size. Consider re-exporting with a narrower selection of issues.
+This attachment has been truncated to avoid exceeding a maximum allowed attachment size of 20MB. <%= @written_count %> of <%= @issues_count %> issues have been included. Consider re-exporting with a narrower selection of issues.
 <% end %>
\ No newline at end of file

lib/csv_builder.rb

@@ -23,6 +23,7 @@ class CsvBuilder
     @header_to_value_hash = header_to_value_hash
     @collection = collection
     @truncated = false
+    @rows_written = 0
   end
 
   # Renders the csv to a string
@@ -45,6 +46,26 @@ class CsvBuilder
     @truncated
   end
 
+  def rows_written
+    @rows_written
+  end
+
+  def rows_expected
+    if truncated? || rows_written == 0
+      @collection.count
+    else
+      rows_written
+    end
+  end
+
+  def status
+    {
+      truncated: truncated?,
+      rows_written: rows_written,
+      rows_expected: rows_expected
+    }
+  end
+
   private
 
   def headers
@@ -71,6 +92,8 @@ class CsvBuilder
     @collection.find_each do |object|
       csv << row(object)
 
+      @rows_written += 1
+
       if until_block.call
         @truncated = true
         break

spec/lib/csv_builder_spec.rb

@@ -2,12 +2,14 @@ require 'spec_helper'
 
 describe CsvBuilder, lib: true do
   let(:object) { double(question: :answer) }
-  let(:fake_relation) { [object] }
+  let(:fake_relation) { FakeRelation.new([object]) }
   let(:subject) { CsvBuilder.new(fake_relation, 'Q & A' => :question, 'Reversed' => -> (o) { o.question.to_s.reverse }) }
   let(:csv_data) { subject.render }
 
-  before do
-    allow(fake_relation).to receive(:find_each).and_yield(object)
+  class FakeRelation < Array
+    def find_each(&block)
+      each(&block)
+    end
   end
 
   it 'generates a csv' do
@@ -20,23 +22,46 @@ describe CsvBuilder, lib: true do
     subject.render
   end
 
+  it 'counts the number of rows' do
+    subject.render
+
+    expect(subject.rows_written).to eq 1
+  end
+
+  describe 'rows_expected' do
+    it 'uses rows_written if CSV rendered successfully' do
+      subject.render
+
+      expect(fake_relation).not_to receive(:count)
+      expect(subject.rows_expected).to eq 1
+    end
+
+    it 'falls back to calling .count before rendering begins' do
+      expect(subject.rows_expected).to eq 1
+    end
+  end
+
   describe 'truncation' do
     let(:big_object) { double(question: 'Long' * 1024) }
     let(:row_size) { big_object.question.length * 2 }
+    let(:fake_relation) { FakeRelation.new([big_object, big_object, big_object]) }
 
-    before do
-      allow(fake_relation).to receive(:find_each).and_yield(big_object)
-                                                 .and_yield(big_object)
-                                                 .and_yield(big_object)
-    end
-
-    it 'after given number of bytes' do
+    it 'occurs after given number of bytes' do
       expect(subject.render(row_size * 2).length).to be_between(row_size * 2, row_size * 3)
       expect(subject).to be_truncated
+      expect(subject.rows_written).to eq 2
     end
 
     it 'is ignored by default' do
       expect(subject.render.length).to be > row_size * 3
+      expect(subject.rows_written).to eq 3
+    end
+
+    it 'causes rows_expected to fall back to .count' do
+      subject.render(0)
+
+      expect(fake_relation).to receive(:count).and_call_original
+      expect(subject.rows_expected).to eq 3
     end
   end
 

spec/mailers/emails/issues_spec.rb

@@ -8,8 +8,8 @@ describe Notify do
   describe 'csv export email' do
     let(:user) { create(:user) }
     let(:empty_project) { create(:empty_project, path: 'myproject') }
-    let(:truncated) { false }
-    subject { Notify.issues_csv_email(user, empty_project, "dummy content", 3, truncated) }
+    let(:export_status) { { truncated: false, rows_expected: 3, rows_written: 3 } }
+    subject { Notify.issues_csv_email(user, empty_project, "dummy content", export_status) }
     let(:attachment) { subject.attachments.first }
 
     it 'attachment has csv mime type' do
@@ -33,11 +33,15 @@ describe Notify do
     end
 
     context 'when truncated' do
-      let(:truncated) { true }
+      let(:export_status) { { truncated: true, rows_expected: 12, rows_written: 10 } }
 
       it 'mentions that the csv has been truncated' do
         expect(subject).to have_content 'truncated'
       end
+
+      it 'mentions the number of issues written and expected' do
+        expect(subject).to have_content '10 of 12 issues'
+      end
     end
   end
 end

spec/mailers/previews/issues_csv_mailer_preview.rb

@@ -2,8 +2,17 @@ class IssuesCsvMailerPreview < ActionMailer::Preview
   def issues_csv_export
     user = OpenStruct.new(notification_email: 'a@example.com')
     project = Project.unscoped.first
-    issues_count = 891
 
-    Notify.issues_csv_email(user, project, "Dummy,Csv\n0,1", issues_count, [true, false].sample)
+    Notify.issues_csv_email(user, project, "Dummy,Csv\n0,1", export_status)
+  end
+
+  private
+
+  def export_status
+    {
+      truncated: [true, false].sample,
+      rows_written: 632,
+      rows_expected: 891
+    }
   end
 end