From 16a4012c1add42673dfedf57058397adb325d60c Mon Sep 17 00:00:00 2001
From: Earlopain <14981592+Earlopain@users.noreply.github.com>
Date: Mon, 29 Apr 2024 14:48:23 +0200
Subject: [PATCH] Handle encoding error from the parser gem

This specific exception has been added only in the most recent release.
Previously it threw an `ArgumentError`.
---
 changelog/.gitkeep                                |  0
 changelog/fix_error_for_magic_encoding_comment.md |  1 +
 lib/rubocop/ast/processed_source.rb               |  2 +-
 rubocop-ast.gemspec                               |  2 +-
 spec/rubocop/ast/processed_source_spec.rb         | 10 ++++++++++
 5 files changed, 13 insertions(+), 2 deletions(-)
 create mode 100644 changelog/.gitkeep
 create mode 100644 changelog/fix_error_for_magic_encoding_comment.md

diff --git a/changelog/.gitkeep b/changelog/.gitkeep
new file mode 100644
index 000000000..e69de29bb
diff --git a/changelog/fix_error_for_magic_encoding_comment.md b/changelog/fix_error_for_magic_encoding_comment.md
new file mode 100644
index 000000000..30b77de39
--- /dev/null
+++ b/changelog/fix_error_for_magic_encoding_comment.md
@@ -0,0 +1 @@
+* [#289](https://github.com/rubocop/rubocop-ast/pull/289): Fix an error during parsing when encountering unknown encodings in the encoding magic comment. ([@Earlopain][])
diff --git a/lib/rubocop/ast/processed_source.rb b/lib/rubocop/ast/processed_source.rb
index 116f40c56..2100ae800 100644
--- a/lib/rubocop/ast/processed_source.rb
+++ b/lib/rubocop/ast/processed_source.rb
@@ -209,7 +209,7 @@ def parse(source, ruby_version, parser_engine)
 
         begin
           @buffer.source = source
-        rescue EncodingError => e
+        rescue EncodingError, Parser::UnknownEncodingInMagicComment => e
           @parser_error = e
           @ast = nil
           @comments = []
diff --git a/rubocop-ast.gemspec b/rubocop-ast.gemspec
index 7d79bfd7e..24fb8cded 100644
--- a/rubocop-ast.gemspec
+++ b/rubocop-ast.gemspec
@@ -33,7 +33,7 @@ Gem::Specification.new do |s|
     'rubygems_mfa_required' => 'true'
   }
 
-  s.add_runtime_dependency('parser', '>= 3.3.0.4')
+  s.add_runtime_dependency('parser', '>= 3.3.1.0')
 
   ##### Do NOT add `rubocop` (or anything depending on `rubocop`) here. See Gemfile
 end
diff --git a/spec/rubocop/ast/processed_source_spec.rb b/spec/rubocop/ast/processed_source_spec.rb
index cd0e1d4ac..c00fd1d8a 100644
--- a/spec/rubocop/ast/processed_source_spec.rb
+++ b/spec/rubocop/ast/processed_source_spec.rb
@@ -28,6 +28,16 @@ def some_method
       end
     end
 
+    context 'when parsing code with an invalid encoding comment' do
+      let(:source) { '# encoding: foobar' }
+
+      it 'returns a parser error' do
+        expect(processed_source.parser_error).to be_a(Parser::UnknownEncodingInMagicComment)
+        expect(processed_source.parser_error.message)
+          .to include('unknown encoding name - foobar')
+      end
+    end
+
     shared_examples 'invalid parser_engine' do
       it 'raises ArgumentError' do
         expect { processed_source }.to raise_error(ArgumentError) do |e|