Change s_() calls to _() calls

There are no namespaces in the strings so we don't need those

app/helpers/emails_helper.rb

@@ -98,16 +98,17 @@ module EmailsHelper
       case format
       when :html
-        " via merge request #{link_to(merge_request.to_reference, merge_request.web_url)}"
+        merge_request_link = link_to(merge_request.to_reference, merge_request.web_url)
+        _("via merge request %{link}").html_safe % { link: merge_request_link }
       else
         # If it's not HTML nor text then assume it's text to be safe
-        " via merge request #{merge_request.to_reference} (#{merge_request.web_url})"
+        _("via merge request %{link}") % { link: "#{merge_request.to_reference} (#{merge_request.web_url})" }
       end
     when String
       # Technically speaking this should be Commit but per
       # https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/15610#note_163812339
       # we can't deserialize Commit without custom serializer for ActiveJob
-      " via #{closed_via}"
+      _("via %{closed_via}") % { closed_via: closed_via }
     else
       ""
     end

app/services/issues/close_service.rb

@@ -29,7 +29,7 @@ module Issues
         event_service.close_issue(issue, current_user)
         create_note(issue, closed_via) if system_note
-        closed_via = "commit #{closed_via.id}" if closed_via.is_a?(Commit)
+        closed_via = _("commit %{commit_id}") % { commit_id: closed_via.id } if closed_via.is_a?(Commit)
         notification_service.async.close_issue(issue, current_user, closed_via: closed_via) if notifications
         todo_service.close_issue(issue, current_user)

app/views/notify/closed_issue_email.html.haml

 %p
-  Issue was closed by #{sanitize_name(@updated_by.name)} #{closure_reason_text(@closed_via, format: formats.first)}.
+  = _("Issue was closed by %{name} %{reason}").html_safe % { name: sanitize_name(@updated_by.name), reason: closure_reason_text(@closed_via, format: formats.first) }

app/views/notify/closed_issue_email.text.haml

-Issue was closed by #{sanitize_name(@updated_by.name)} #{closure_reason_text(@closed_via, format: formats.first)}.
+= _("Issue was closed by %{name} %{reason}").html_safe % { name: sanitize_name(@updated_by.name), reason: closure_reason_text(@closed_via, format: formats.first) }
 Issue ##{@issue.iid}: #{project_issue_url(@issue.project, @issue)}

changelogs/unreleased/61960-translatable-strings-in-issue-closure-emails.yml

+---
+title: I18n for issue closure reason in emails
+merge_request: 28489
+author: Michał Zając
+type: changed

locale/gitlab.pot

@@ -5444,6 +5444,9 @@ msgstr ""
 msgid "Issue update failed"
 msgstr ""
+msgid "Issue was closed by %{name} %{reason}"
+msgstr ""
+
 msgid "IssueBoards|Board"
 msgstr ""
@@ -11988,6 +11991,9 @@ msgstr ""
 msgid "commented on %{link_to_project}"
 msgstr ""
+msgid "commit %{commit_id}"
+msgstr ""
+
 msgid "confidentiality|You are going to turn off the confidentiality. This means <strong>everyone</strong> will be able to see and leave a comment on this issue."
 msgstr ""
@@ -12513,6 +12519,12 @@ msgstr ""
 msgid "verify ownership"
 msgstr ""
+msgid "via %{closed_via}"
+msgstr ""
+
+msgid "via merge request %{link}"
+msgstr ""
+
 msgid "view it on GitLab"
 msgstr ""

spec/helpers/emails_helper_spec.rb

@@ -8,19 +8,19 @@ describe EmailsHelper do
       context "and format is text" do
         it "returns plain text" do
-          expect(closure_reason_text(merge_request, format: :text)).to eq(" via merge request #{merge_request.to_reference} (#{merge_request_presenter.web_url})")
+          expect(closure_reason_text(merge_request, format: :text)).to eq("via merge request #{merge_request.to_reference} (#{merge_request_presenter.web_url})")
         end
       end
       context "and format is HTML" do
         it "returns HTML" do
-          expect(closure_reason_text(merge_request, format: :html)).to eq(" via merge request #{link_to(merge_request.to_reference, merge_request_presenter.web_url)}")
+          expect(closure_reason_text(merge_request, format: :html)).to eq("via merge request #{link_to(merge_request.to_reference, merge_request_presenter.web_url)}")
         end
       end
       context "and format is unknown" do
         it "returns plain text" do
-          expect(closure_reason_text(merge_request, format: :text)).to eq(" via merge request #{merge_request.to_reference} (#{merge_request_presenter.web_url})")
+          expect(closure_reason_text(merge_request, format: :text)).to eq("via merge request #{merge_request.to_reference} (#{merge_request_presenter.web_url})")
         end
       end
     end
@@ -29,7 +29,7 @@ describe EmailsHelper do
       let(:closed_via) { "5a0eb6fd7e0f133044378c662fcbbc0d0c16dbfa" }
       it "returns plain text" do
-        expect(closure_reason_text(closed_via)).to eq(" via #{closed_via}")
+        expect(closure_reason_text(closed_via)).to eq("via #{closed_via}")
       end
     end