Luhn: A new test case with odd number of digits (#1543)

* Luhn: A new test case with odd number of digits

A new positive test case with odd number of digits and non-zero first digit.

* Update the test file of Luhn problem using problem specification

A new positive test case with odd number of digits and non-zero first digit.

Author: fahadhk

exercises/practice/luhn/.meta/tests.toml

@@ -1,6 +1,13 @@
-# This is an auto-generated file. Regular comments will be removed when this
-# file is regenerated. Regenerating will not touch any manually added keys,
-# so comments can be added in a "comment" key.
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
 
 [792a7082-feb7-48c7-b88b-bbfec160865e]
 description = "single digit strings can not be valid"
@@ -50,6 +57,9 @@ description = "more than a single zero is valid"
 [ab56fa80-5de8-4735-8a4a-14dae588663e]
 description = "input digit 9 is correctly converted to output digit 9"
 
+[8a7c0e24-85ea-4154-9cf1-c2db90eabc08]
+description = "valid luhn with an odd number of digits and non zero first digit"
+
 [39a06a5a-5bad-4e0f-b215-b042d46209b1]
 description = "using ascii value for non-doubled non-digit isn't allowed"
 

exercises/practice/luhn/LuhnTests.cs

@@ -98,6 +98,12 @@ public void Input_digit_9_is_correctly_converted_to_output_digit_9()
         Assert.True(Luhn.IsValid("091"));
     }
 
+    [Fact(Skip = "Remove this Skip property to run this test")]
+    public void Valid_luhn_with_an_odd_number_of_digits_and_non_zero_first_digit()
+    {
+        Assert.True(Luhn.IsValid("109"));
+    }
+
     [Fact(Skip = "Remove this Skip property to run this test")]
     public void Using_ascii_value_for_non_doubled_non_digit_isnt_allowed()
     {