1 files changed, 26 insertions, 5 deletions
diff --git a/lib/prism/translation/parser.rb b/lib/prism/translation/parser.rb
index 5f2f01dbda..70031f133a 100644
--- a/lib/prism/translation/parser.rb
+++ b/lib/prism/translation/parser.rb
@@ -1,9 +1,15 @@
 # frozen_string_literal: true
+# :markup: markdown
 
 begin
+  required_version = ">= 3.3.7.2"
+  gem "parser", required_version
   require "parser"
 rescue LoadError
-  warn(%q{Error: Unable to load parser. Add `gem "parser"` to your Gemfile.})
+  warn(<<~MSG)
+    Error: Unable to load parser #{required_version}. \
+    Add `gem "parser"` to your Gemfile or run `bundle update parser`.
+  MSG
   exit(1)
 end
 
@@ -13,6 +19,13 @@ module Prism
     # whitequark/parser gem's syntax tree. It inherits from the base parser for
     # the parser gem, and overrides the parse* methods to parse with prism and
     # then translate.
+    #
+    # Note that this version of the parser always parses using the latest
+    # version of Ruby syntax supported by Prism. If you want specific version
+    # support, use one of the version-specific subclasses, such as
+    # `Prism::Translation::Parser34`. If you want to parse using the same
+    # version of Ruby syntax as the currently running version of Ruby, use
+    # `Prism::Translation::ParserCurrent`.
     class Parser < ::Parser::Base
       Diagnostic = ::Parser::Diagnostic # :nodoc:
       private_constant :Diagnostic
@@ -20,7 +33,7 @@ module Prism
       # The parser gem has a list of diagnostics with a hard-coded set of error
       # messages. We create our own diagnostic class in order to set our own
       # error messages.
-      class PrismDiagnostic < Diagnostic
+      class PrismDiagnostic < Diagnostic # :nodoc:
         # This is the cached message coming from prism.
         attr_reader :message
 
@@ -59,13 +72,19 @@ module Prism
       # should be implemented as needed.
       #
       def initialize(builder = Prism::Translation::Parser::Builder.new, parser: Prism)
+        if !builder.is_a?(Prism::Translation::Parser::Builder)
+          warn(<<~MSG, uplevel: 1, category: :deprecated)
+            [deprecation]: The builder passed to `Prism::Translation::Parser.new` is not a \
+            `Prism::Translation::Parser::Builder` subclass. This will raise in the next major version.
+          MSG
+        end
         @parser = parser
 
         super(builder)
       end
 
       def version # :nodoc:
-        34
+        41
       end
 
       # The default encoding for Ruby files is UTF-8.
@@ -337,8 +356,10 @@ module Prism
           "3.3.1"
         when 34
           "3.4.0"
-        when 35
-          "3.5.0"
+        when 35, 40
+          "4.0.0"
+        when 41
+          "4.1.0"
         else
           "latest"
         end