added minimum limit to wiki page

app/helpers/application_settings_helper.rb

@@ -328,7 +328,8 @@ module ApplicationSettingsHelper
       :group_import_limit,
       :group_export_limit,
       :group_download_export_limit,
-      :wiki_page_max_content_bytes
+      :wiki_page_max_content_bytes,
+      :wiki_page_min_content_bytes
     ]
   end
 

app/models/application_setting.rb

@@ -273,6 +273,7 @@ class ApplicationSetting < ApplicationRecord
 
   validates :snippet_size_limit, numericality: { only_integer: true, greater_than: 0 }
   validates :wiki_page_max_content_bytes, numericality: { only_integer: true, greater_than: 0 }
+  validates :wiki_page_min_content_bytes, numericality: { only_integer: true, greater_than: 0 }
 
   validates :email_restrictions, untrusted_regexp: true
 

app/models/application_setting_implementation.rb

@@ -165,7 +165,8 @@ module ApplicationSettingImplementation
         user_default_external: false,
         user_default_internal_regex: nil,
         user_show_add_ssh_key_message: true,
-        wiki_page_max_content_bytes: 50.megabytes
+        wiki_page_max_content_bytes: 50.megabytes,
+        wiki_page_min_content_bytes: 1.kilobytes
       }
     end
 

app/models/wiki_page.rb

@@ -408,11 +408,19 @@ class WikiPage
   def validate_content_size_limit
     current_value = raw_content.to_s.bytesize
     max_size = Gitlab::CurrentSettings.wiki_page_max_content_bytes
-    return if current_value <= max_size
+    min_size = Gitlab::CurrentSettings.wiki_page_min_content_bytes
+    return if current_value <= max_size && current_value >= min_size
 
-    errors.add(:content, _('is too long (%{current_value}). The maximum size is %{max_size}.') % {
-      current_value: ActiveSupport::NumberHelper.number_to_human_size(current_value),
-      max_size: ActiveSupport::NumberHelper.number_to_human_size(max_size)
-    })
+    if current_value > max_size
+      errors.add(:content, _('is too long (%{current_value}). The maximum size is %{max_size}.') % {
+        current_value: ActiveSupport::NumberHelper.number_to_human_size(current_value),
+        max_size: ActiveSupport::NumberHelper.number_to_human_size(max_size)
+      })
+    else
+      errors.add(:content, _('is too short (%{current_value}). The minimum size is %{min_size}.') % {
+        current_value: ActiveSupport::NumberHelper.number_to_human_size(current_value),
+        min_size: ActiveSupport::NumberHelper.number_to_human_size(min_size)
+      })
+    end
   end
 end

spec/models/application_setting_spec.rb

@@ -73,6 +73,7 @@ RSpec.describe ApplicationSetting do
 
     it { is_expected.to validate_numericality_of(:snippet_size_limit).only_integer.is_greater_than(0) }
     it { is_expected.to validate_numericality_of(:wiki_page_max_content_bytes).only_integer.is_greater_than(0) }
+    it { is_expected.to validate_numericality_of(:wiki_page_min_content_bytes).only_integer.is_greater_than(0) }
     it { is_expected.to validate_presence_of(:max_artifacts_size) }
     it { is_expected.to validate_numericality_of(:max_artifacts_size).only_integer.is_greater_than(0) }
     it { is_expected.to validate_presence_of(:max_pages_size) }

spec/models/wiki_page_spec.rb

@@ -275,6 +275,7 @@ RSpec.describe WikiPage do
       context 'with a new page' do
         before do
           stub_application_setting(wiki_page_max_content_bytes: 10)
+          stub_application_setting(wiki_page_min_content_bytes: 2)
         end
 
         it 'accepts content below the limit' do
@@ -283,6 +284,12 @@ RSpec.describe WikiPage do
           expect(subject).to be_valid
         end
 
+        it 'accepts content above the limit' do
+          subject.attributes[:content] = 'a' * 2
+
+          expect(subject).to be_valid
+        end
+
         it 'rejects content exceeding the limit' do
           subject.attributes[:content] = 'a' * 11
 
@@ -292,6 +299,15 @@ RSpec.describe WikiPage do
           )
         end
 
+        it 'rejects content below the limit' do
+          subject.attributes[:content] = 'a'
+
+          expect(subject).not_to be_valid
+          expect(subject.errors.messages).to eq(
+            content: ['is too short (1 Bytes). The minimum size is 2 Bytes.']
+          )
+        end
+
         it 'counts content size in bytes rather than characters' do
           subject.attributes[:content] = '💩💩💩'
 
@@ -308,13 +324,14 @@ RSpec.describe WikiPage do
         before do
           subject
           stub_application_setting(wiki_page_max_content_bytes: 11)
+          stub_application_setting(wiki_page_min_content_bytes: 2)
         end
 
         it 'accepts content when it has not changed' do
           expect(subject).to be_valid
         end
 
-        it 'rejects content when it has changed' do
+        it 'rejects content when it has changed and exceeds the limit' do
           subject.attributes[:content] = 'a' * 12
 
           expect(subject).not_to be_valid
@@ -322,6 +339,15 @@ RSpec.describe WikiPage do
             content: ['is too long (12 Bytes). The maximum size is 11 Bytes.']
           )
         end
+
+        it 'rejects content when it has changed and is below the limit' do
+          subject.attributes[:content] = 'a' * 1
+
+          expect(subject).not_to be_valid
+          expect(subject.errors.messages).to eq(
+            content: ['is too short (1 Bytes). The minimum size is 2 Bytes.']
+          )
+        end
       end
     end