FEATURE: Allow excluding uploads from min post length requirement (#31194)

Currently, the markdown for uploads is counted towards post minimum length requirements. This change introduces a site setting `prevent_uploads_only_posts` which can be flipped to exclude upload segments from the calculation.

spec/lib/validators/post_validator_spec.rb

@@ -46,7 +46,7 @@ RSpec.describe PostValidator do
     end
   end
 
-  describe "stripped_length" do
+  describe "#stripped_length" do
     it "adds an error for short raw" do
       post.raw = "abc"
       validator.stripped_length(post)
@@ -103,6 +103,26 @@ RSpec.describe PostValidator do
       validator.stripped_length(post)
       expect(post.errors.count).to eq(1)
     end
+
+    context "when configured to count uploads" do
+      before { SiteSetting.prevent_uploads_only_posts = false }
+
+      it "counts image tags" do
+        post.raw = "![A cute cat|690x472](upload://3NvZqZ2iBHjDjwNVI4QyZpkaC5r.png)"
+        validator.stripped_length(post)
+        expect(post.errors.count).to eq(0)
+      end
+    end
+
+    context "when configured to not count uploads" do
+      before { SiteSetting.prevent_uploads_only_posts = true }
+
+      it "doesn't count image tags" do
+        post.raw = "![A cute cat|690x472](upload://3NvZqZ2iBHjDjwNVI4QyZpkaC5r.png)"
+        validator.stripped_length(post)
+        expect(post.errors.count).to eq(1)
+      end
+    end
   end
 
   describe "max_posts_validator" do