diff --git a/tests/scripts/check_test_cases.py b/tests/scripts/check_test_cases.py
index 35a9987..f25b602 100755
--- a/tests/scripts/check_test_cases.py
+++ b/tests/scripts/check_test_cases.py
@@ -76,10 +76,13 @@
                         len(description))
     seen[description] = line_number
 
-def check_test_suite(results, data_file_name):
-    """Check the test cases in the given unit test data file."""
+def walk_test_suite(function, results, descriptions, data_file_name):
+    """Iterate over the test cases in the given unit test data file.
+
+Call function(results, descriptions, data_file_name, line_number, description)
+on each description.
+"""
     in_paragraph = False
-    descriptions = {}
     with open(data_file_name, 'rb') as data_file:
         for line_number, line in enumerate(data_file, 1):
             line = line.rstrip(b'\r\n')
@@ -90,13 +93,16 @@
                 continue
             if not in_paragraph:
                 # This is a test case description line.
-                check_description(results, descriptions,
-                                  data_file_name, line_number, line)
+                function(results, descriptions,
+                         data_file_name, line_number, line)
             in_paragraph = True
 
-def check_ssl_opt_sh(results, file_name):
-    """Check the test cases in ssl-opt.sh or a file with a similar format."""
-    descriptions = {}
+def walk_ssl_opt_sh(function, results, descriptions, file_name):
+    """Iterate over the test cases in ssl-opt.sh or a file with a similar format.
+
+Call function(results, descriptions, file_name, line_number, description)
+on each description.
+"""
     with open(file_name, 'rb') as file_contents:
         for line_number, line in enumerate(file_contents, 1):
             # Assume that all run_test calls have the same simple form
@@ -106,8 +112,23 @@
             if not m:
                 continue
             description = m.group(1)
-            check_description(results, descriptions,
-                              file_name, line_number, description)
+            function(results, descriptions,
+                     file_name, line_number, description)
+
+def walk_all(function, results):
+    """Iterate over all named test cases.
+
+Call function(results, {}, file_name, line_number, description)
+on each description.
+"""
+    test_directories = collect_test_directories()
+    for directory in test_directories:
+        for data_file_name in glob.glob(os.path.join(directory, 'suites',
+                                                     '*.data')):
+            walk_test_suite(function, results, {}, data_file_name)
+        ssl_opt_sh = os.path.join(directory, 'ssl-opt.sh')
+        if os.path.exists(ssl_opt_sh):
+            walk_ssl_opt_sh(function, results, {}, ssl_opt_sh)
 
 def main():
     parser = argparse.ArgumentParser(description=__doc__)
@@ -118,15 +139,8 @@
                         action='store_false', dest='quiet',
                         help='Show warnings (default: on; undoes --quiet)')
     options = parser.parse_args()
-    test_directories = collect_test_directories()
     results = Results(options)
-    for directory in test_directories:
-        for data_file_name in glob.glob(os.path.join(directory, 'suites',
-                                                     '*.data')):
-            check_test_suite(results, data_file_name)
-        ssl_opt_sh = os.path.join(directory, 'ssl-opt.sh')
-        if os.path.exists(ssl_opt_sh):
-            check_ssl_opt_sh(results, ssl_opt_sh)
+    walk_all(check_description, results)
     if (results.warnings or results.errors) and not options.quiet:
         sys.stderr.write('{}: {} errors, {} warnings\n'
                          .format(sys.argv[0], results.errors, results.warnings))