Test/add check if all as appears before all bs tests

problems/easy/check_if_all_a_s_appears_before_all_b_s_2124/solution.py

@@ -0,0 +1,17 @@
+# Tags: String
+class Solution:
+    def check_string(self, s: str) -> bool:
+        """
+        Time Complexity: O(n) where n is the length of string s
+                         - We iterate through the string exactly once
+        Space Complexity: O(1)
+                          - Only a single boolean variable is used
+        """
+        is_b_appear = False
+        for c in s:
+            if c == 'b':
+                is_b_appear = True
+            else:
+                if is_b_appear:
+                    return False
+        return True

problems/easy/check_if_all_a_s_appears_before_all_b_s_2124/test_solution.py

@@ -0,0 +1,15 @@
+import pytest
+from tests.base_test import BaseTestSolution
+from .solution import Solution
+
+
+class TestSolution(BaseTestSolution):
+    solution = Solution()
+
+    @pytest.mark.parametrize("method_name, s, expected, timeout", [
+        ('check_string', "aaabbb", True, None),
+        ('check_string', "abab", False, None),
+        ('check_string', "bbb", True, None),
+    ])
+    def test_check_string(self, method_name, s, expected, timeout):
+        self._run_test(self.solution, method_name, (s,), expected, timeout)