record: Nummern unter 1 und Text sind ein Fehler statt Zeilen vom Ende

test/rdb_test.rb

@@ -5,6 +5,20 @@ require 'pty'
 require_relative '../lib/rdb'
 
 class SelectionTest < RdbCase
+  def test_record_rejects_numbers_below_one_and_junk
+    %w[0 -1 abc 2.5].each do |n|
+      out, err, st = run3('record', n, stdin: File.read(File.join(@dir, 'owners')))
+      refute st.success?, "record #{n} should fail"
+      assert_equal '', out
+      assert_match(/not a record number/, err)
+    end
+  end
+
+  def test_record_beyond_the_end_is_an_empty_table
+    assert_equal [], data(rdb('record', '9', file: 'owners'))
+    assert_equal [%w[6 cy]], data(rdb('record', '3', file: 'owners'))
+  end
+
   def test_row_numeric_condition
     out = rdb('row', 'Cost > 5', file: 'inventory')
     assert_equal %w[3 6 7], data(out).map(&:first)