From 70c72cc8c0eb7c57385a45026f8e1fe311d23a7f Mon Sep 17 00:00:00 2001
From: Kevin Newton <kddnewton@gmail.com>
Date: Sun, 26 Apr 2026 10:03:53 -0400
Subject: [PATCH] Add ability to configure parser

This provides the ability to set the configured parser, switching
between ripper and prism when prism is available.
---
 lib/power_assert/configuration.rb | 16 ++++++++++++++--
 lib/power_assert/context.rb       |  3 ++-
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/lib/power_assert/configuration.rb b/lib/power_assert/configuration.rb
index 825c2d2..0052fa7 100644
--- a/lib/power_assert/configuration.rb
+++ b/lib/power_assert/configuration.rb
@@ -1,7 +1,7 @@
 module PowerAssert
   class << self
     def configuration
-      @configuration ||= Configuration[false, true, false, :p]
+      @configuration ||= Configuration[false, true, false, :p, :ripper]
     end
 
     def configure
@@ -9,7 +9,7 @@ def configure
     end
   end
 
-  class Configuration < Struct.new(:lazy_inspection, :_redefinition, :colorize_message, :inspector)
+  class Configuration < Struct.new(:lazy_inspection, :_redefinition, :colorize_message, :inspector, :parser)
     def colorize_message=(bool)
       if bool
         require 'irb/color'
@@ -41,6 +41,18 @@ def inspector=(inspector)
       end
       super
     end
+
+    def parser=(parser)
+      case parser
+      when :prism
+        require 'prism'
+      when :ripper
+        require 'ripper'
+      else
+        raise ArgumentError, "unknown parser: #{parser}"
+      end
+      super
+    end
   end
   private_constant :Configuration
 end
diff --git a/lib/power_assert/context.rb b/lib/power_assert/context.rb
index cddc442..b383303 100644
--- a/lib/power_assert/context.rb
+++ b/lib/power_assert/context.rb
@@ -30,7 +30,8 @@ def initialize(assertion_proc_or_source, assertion_method, source_binding)
             line ||= File.open(path) {|fp| fp.each_line.drop(lineno - 1).first }
           end
           if line
-            @parser = Parser::RipperParser.new(line, path, lineno, @assertion_proc.binding, assertion_method.to_s, @assertion_proc)
+            parser_class = PowerAssert.configuration.parser == :prism ? Parser::PrismParser : Parser::RipperParser
+            @parser = parser_class.new(line, path, lineno, @assertion_proc.binding, assertion_method.to_s, @assertion_proc)
           end
         end
       end