From 6934edd97cfdc855d5882e85415b33f573db120c Mon Sep 17 00:00:00 2001
From: Alan Guo Xiang Tan <gxtan1990@gmail.com>
Date: Tue, 31 Jan 2023 08:57:13 +0800
Subject: [PATCH] DEV: Add hidden site setting to configure search ranking
 weights (#20086)

This site setting is mostly experimental at this point.
---
 config/site_settings.yml |  3 +++
 lib/search.rb            |  1 +
 spec/lib/search_spec.rb  | 22 ++++++++++++++++++++++
 3 files changed, 26 insertions(+)

diff --git a/config/site_settings.yml b/config/site_settings.yml
index 0ec95ded873..4d40276b7af 100644
--- a/config/site_settings.yml
+++ b/config/site_settings.yml
@@ -2202,6 +2202,9 @@ search:
   search_ranking_normalization:
     default: "0"
     hidden: true
+  search_ranking_weights:
+    default: ""
+    hidden: true
   min_search_term_length:
     client: true
     default: 3
diff --git a/lib/search.rb b/lib/search.rb
index 0429afe2bbd..994e37fadf8 100644
--- a/lib/search.rb
+++ b/lib/search.rb
@@ -1134,6 +1134,7 @@ class Search
     elsif !is_topic_search
       rank = <<~SQL
       TS_RANK_CD(
+        #{SiteSetting.search_ranking_weights.present? ? "'#{SiteSetting.search_ranking_weights}'," : ""}
         post_search_data.search_data,
         #{@term.blank? ? "" : ts_query(weight_filter: weights)},
         #{SiteSetting.search_ranking_normalization}|32
diff --git a/spec/lib/search_spec.rb b/spec/lib/search_spec.rb
index 4388a13ebde..fdc91daad44 100644
--- a/spec/lib/search_spec.rb
+++ b/spec/lib/search_spec.rb
@@ -113,6 +113,28 @@ RSpec.describe Search do
         expect(Search.execute("oeuvre").posts).to contain_exactly(post_2)
       end
     end
+
+    context "when search_ranking_weights site setting has been configured" do
+      fab!(:topic) { Fabricate(:topic, title: "Some random topic title start") }
+      fab!(:topic2) { Fabricate(:topic, title: "Some random topic title") }
+      fab!(:post1) { Fabricate(:post, raw: "start", topic: topic) }
+      fab!(:post2) { Fabricate(:post, raw: "#{"start " * 100}", topic: topic2) }
+
+      before do
+        SearchIndexer.enable
+        [post1, post2].each { |post| SearchIndexer.index(post, force: true) }
+      end
+
+      after { SearchIndexer.disable }
+
+      it "should apply the custom ranking weights correctly" do
+        expect(Search.execute("start").posts).to eq([post2, post1])
+
+        SiteSetting.search_ranking_weights = "{0.00001,0.2,0.4,1.0}"
+
+        expect(Search.execute("start").posts).to eq([post1, post2])
+      end
+    end
   end
 
   context "with apostrophes" do