Refactor multi-prism version logic

schneems · schneems · commit ab122c455f2a · 2026-01-20T15:32:33.000-06:00
The reason this logic for different methods branches in the class instead of internally was to be eagerly aggressive about runtime performance. This code is currently only used once for the document where it's invoked ~N times (where N is number of lines): ```ruby module SyntaxSuggest class CleanDocument # ... def join_trailing_slash! trailing_groups = @document.select(&:trailing_slash?).map do |code_line| take_while_including(code_line.index..) { |x| x.trailing_slash? } end join_groups(trailing_groups) self end ``` Since this is not currently a hot-spot I think merging the branches and using a case statement is a reasonable tradeoff and avoids the need to do specific version testing. An alternative idea was presented in #241 of behavior-based testing for branch logic (which I would prefer), however, calling the code triggered requiring a `DelegateClass` when the `syntax_suggest/api` is being required.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,6 +1,6 @@
 ## HEAD (unreleased)
 
-- Fix: Correctly identify trailing slashes when using Prism > 1.8.0. (https://github.com/ruby/syntax_suggest/pull/241)
+- Fix: Correctly identify trailing slashes when using Prism > 1.8.0. (https://github.com/ruby/syntax_suggest/pull/243)
 - Internal: Add tests to multiple versions of prism
 
 ## 2.0.2
diff --git a/lib/syntax_suggest/code_line.rb b/lib/syntax_suggest/code_line.rb
@@ -180,21 +180,17 @@ def ignore_newline_not_beg?
     #     EOM
     #     expect(lines.first.trailing_slash?).to eq(true)
     #
-    if SyntaxSuggest.use_prism_parser? && Prism::VERSION <= "1.8.0"
-      # Older versions of prism didn't correctly emit on_sp
-      def trailing_slash?
-        last = @lex.last
-        return false unless last
-
-        last.type == :on_tstring_end || (last.type == :on_sp && last.token == TRAILING_SLASH)
-      end
-    else
-      def trailing_slash?
-        last = @lex.last
-        return false unless last
-        return false unless last.type == :on_sp
+    def trailing_slash?
+      last = @lex.last
 
+      # Older versions of prism diverged slightly from Ripper in compatibility mode
+      case last&.type
+      when :on_sp
         last.token == TRAILING_SLASH
+      when :on_tstring_end
+        true
+      else
+        false
       end
     end
 
