feat(content): function signatures + test cases

backend/data/questions/reverse-string.yaml

@@ -9,6 +9,24 @@ categories:
 patterns:
   - two-pointers
 
+function_signature: "def reverse_string(s: list[str]) -> None:"
+
+test_cases:
+  visible:
+    - input: { s: ["h", "e", "l", "l", "o"] }
+      expected: ["o", "l", "l", "e", "h"]
+    - input: { s: ["H", "a", "n", "n", "a", "h"] }
+      expected: ["h", "a", "n", "n", "a", "H"]
+  hidden:
+    - input: { s: ["a"] }
+      expected: ["a"]
+    - input: { s: ["a", "b"] }
+      expected: ["b", "a"]
+    - input: { s: ["a", "b", "c"] }
+      expected: ["c", "b", "a"]
+    - input: { s: ["1", "2", "3", "4", "5"] }
+      expected: ["5", "4", "3", "2", "1"]
+
 description: |
   Write a function that reverses a string. The input string is given as an array of characters `s`.