Add some docstrings for the sanity checker.

Author: Julian

bin/jsonschema_suite

@@ -33,25 +33,37 @@ with open(os.path.join(ROOT_DIR, "test-schema.json")) as schema:
 
 
 def files(paths):
+    """
+    Each test file in the provided paths.
+    """
     for path in paths:
         with open(path) as test_file:
             yield json.load(test_file)
 
 
 def groups(paths):
+    """
+    Each test group within each file in the provided paths.
+    """
     for test_file in files(paths):
         for group in test_file:
             yield group
 
 
 def cases(paths):
+    """
+    Each individual test case within all groups within the provided paths.
+    """
     for test_group in groups(paths):
         for test in test_group["tests"]:
             test["schema"] = test_group["schema"]
             yield test
 
 
 def collect(root_dir):
+    """
+    All of the test file paths within the given root directory, recursively.
+    """
     for root, _, files in os.walk(root_dir):
         for filename in fnmatch.filter(files, "*.json"):
             yield os.path.join(root, filename)