1 files changed, 135 insertions, 0 deletions
diff --git a/test/prism/errors_test.rb b/test/prism/errors_test.rb
new file mode 100644
index 0000000000..9dd7fbe3fe
--- /dev/null
+++ b/test/prism/errors_test.rb
@@ -0,0 +1,135 @@
+# frozen_string_literal: true
+
+return if RUBY_VERSION < "3.3.0"
+
+require_relative "test_helper"
+
+module Prism
+  class ErrorsTest < TestCase
+    base = File.expand_path("errors", __dir__)
+    filepaths = Dir[ENV.fetch("FOCUS", "**/*.txt"), base: base]
+
+    PARSE_Y_EXCLUDES = [
+      # https://bugs.ruby-lang.org/issues/20409
+      "#{base}/4.1/end_block_exit.txt"
+    ]
+
+    filepaths.each do |filepath|
+      ruby_versions_for(filepath).each do |version|
+        define_method(:"test_#{version}_#{File.basename(filepath, ".txt")}") do
+          assert_errors(File.join(base, filepath), version)
+        end
+      end
+    end
+
+    def test_newline_preceding_eof
+      err = Prism.parse("foo(").errors.first
+      assert_equal 1, err.location.start_line
+
+      err = Prism.parse("foo(\n").errors.first
+      assert_equal 1, err.location.start_line
+
+      err = Prism.parse("foo(\n\n\n\n\n").errors.first
+      assert_equal 5, err.location.start_line
+    end
+
+    def test_embdoc_ending
+      source = <<~RUBY
+        =begin\n=end
+        =begin\n=end\0
+        =begin\n=end\C-d
+        =begin\n=end\C-z
+      RUBY
+
+      source.each_line do |line|
+        assert_valid_syntax(source)
+        assert_predicate Prism.parse(source), :success?
+      end
+    end
+
+    def test_unterminated_string_closing
+      statement = Prism.parse_statement("'hello")
+      assert_equal statement.unescaped, "hello"
+      assert_nil statement.closing
+    end
+
+    def test_unterminated_interpolated_string_closing
+      statement = Prism.parse_statement('"hello')
+      assert_equal statement.unescaped, "hello"
+      assert_nil statement.closing
+    end
+
+    def test_unterminated_empty_string_closing
+      statement = Prism.parse_statement('"')
+      assert_empty statement.unescaped
+      assert_nil statement.closing
+    end
+
+    def test_regexp_encoding_option_mismatch_error
+      # UTF-8 char with ASCII-8BIT modifier
+      result = Prism.parse('/Ȃ/n')
+      assert_includes result.errors.map(&:type), :regexp_encoding_option_mismatch
+
+      # UTF-8 char with EUC-JP modifier
+      result = Prism.parse('/Ȃ/e')
+      assert_includes result.errors.map(&:type), :regexp_encoding_option_mismatch
+
+      # UTF-8 char with Windows-31J modifier
+      result = Prism.parse('/Ȃ/s')
+      assert_includes result.errors.map(&:type), :regexp_encoding_option_mismatch
+
+      # UTF-8 char with UTF-8 modifier
+      result = Prism.parse('/Ȃ/u')
+      assert_empty result.errors
+    end
+
+    def test_incomplete_def_closing_loc
+      statement = Prism.parse_statement("def f; 123")
+      assert_nil(statement.end_keyword)
+    end
+
+    def test_unclosed_interpolation
+      statement = Prism.parse_statement("\"\#{")
+      assert_equal('"', statement.opening)
+      assert_nil(statement.closing)
+
+      assert_equal(1, statement.parts.count)
+      assert_equal('#{', statement.parts[0].opening)
+      assert_equal("", statement.parts[0].closing)
+      assert_nil(statement.parts[0].statements)
+    end
+
+    def test_unclosed_heredoc_and_interpolation
+      statement = Prism.parse_statement("<<D\n\#{")
+      assert_equal("<<D", statement.opening)
+      assert_nil(statement.closing)
+
+      assert_equal(1, statement.parts.count)
+      assert_equal('#{', statement.parts[0].opening)
+      assert_equal("", statement.parts[0].closing)
+      assert_nil(statement.parts[0].statements)
+    end
+
+    private
+
+    def assert_errors(filepath, version)
+      expected = File.read(filepath, binmode: true, external_encoding: Encoding::UTF_8)
+
+      source = expected.lines.grep_v(/^\s*\^/).join.gsub(/\n*\z/, "")
+      if CURRENT_MAJOR_MINOR == version && !PARSE_Y_EXCLUDES.include?(filepath)
+        refute_valid_syntax(source)
+      end
+
+      result = Prism.parse(source, version: version)
+      errors = result.errors
+      refute_empty errors, "Expected errors in #{filepath}"
+
+      actual = result.errors_format
+      if expected != actual && ENV["UPDATE_SNAPSHOTS"]
+        File.write(filepath, actual)
+      end
+
+      assert_equal expected, actual, "Expected errors to match for #{filepath}"
+    end
+  end
+end