From 09e76147b96480418977b0bf1963baf91487b4d3 Mon Sep 17 00:00:00 2001
From: Jonathan Hefner <jonathan@hefner.pro>
Date: Sat, 21 Oct 2023 13:10:20 -0500
Subject: [PATCH] Exclude downcased acronym bigrams

This prevents some unexpected results.  For example, matching
`ActionCable::Connection::StreamEventLoop` when searching for "select"
due to "S"tream"E"vent"L"oop.
---
 lib/sdoc/search_index.rb  | 4 ++--
 spec/search_index_spec.rb | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/sdoc/search_index.rb b/lib/sdoc/search_index.rb
index 0ca0f193..1b3063f6 100644
--- a/lib/sdoc/search_index.rb
+++ b/lib/sdoc/search_index.rb
@@ -36,14 +36,14 @@ def derive_bigrams(name)
     # Example: "ActiveSupport::Cache::Store" => ":ActiveSupport:Cache:Store"
     strings = [":#{name}".gsub("::", ":")]
 
+    # Example: ":ActiveModel:API" => ":activemodel:api"
+    strings.concat(strings.map(&:downcase))
     # Example: ":ActiveSupport:HashWithIndifferentAccess" => ":AS:HWIA"
     strings.concat(strings.map { |string| string.gsub(/([A-Z])[a-z]+/, '\1') })
     # Example: ":AbstractController:Base#action_name" => " AbstractController Base action_name"
     strings.concat(strings.map { |string| string.tr(":#", " ") })
     # Example: ":AbstractController:Base#action_name" => ":AbstractController:Base#actionname"
     strings.concat(strings.map { |string| string.tr("_", "") })
-    # Example: ":ActiveModel:API" => ":activemodel:api"
-    strings.concat(strings.map(&:downcase))
 
     # Example: ":ActiveModel:Name#<=>" => [":ActiveModel", ":Name", "#<=>"]
     strings.map! { |string| string.split(/(?=[ :#])/) }.flatten!
diff --git a/spec/search_index_spec.rb b/spec/search_index_spec.rb
index c7934bae..d240d71f 100644
--- a/spec/search_index_spec.rb
+++ b/spec/search_index_spec.rb
@@ -99,10 +99,10 @@ def hoge_fuga; end
       _(bigrams).wont_include "GR"
     end
 
-    it "includes downcased bigrams" do
+    it "includes downcased bigrams except for acronym bigrams" do
       bigrams = SDoc::SearchIndex.derive_bigrams("AbcDefGhi::RstUvwXyz")
 
-      bigrams.grep(/[A-Z]/).each do |uppercase|
+      bigrams.grep(/[A-Z]/).grep_v(/[A-Z]{2}/).each do |uppercase|
         _(bigrams).must_include uppercase.downcase
       end
     end