Reformatting.

[python_utils.git] / unittest_utils.py

diff --git a/unittest_utils.py b/unittest_utils.py
index 584eb3ce002d3fed3363223cbe4a3cf9059313a6..d63f2b566b51b33bc794340b0d425d29a7e89142 100644 (file)
--- a/unittest_utils.py
+++ b/unittest_utils.py
@@ -24,6 +24,7 @@ import warnings
 
 import bootstrap
 import config
+import function_utils
 import scott_secrets
 
 import sqlalchemy as sa
@@ -145,29 +146,6 @@ class DatabasePerfRegressionDataPersister(PerfRegressionDataPersister):
         self.conn.execute(sql)
 
 
-def function_identifier(f: Callable) -> str:
-    """
-    Given a callable function, return a string that identifies it.
-    Usually that string is just __module__:__name__ but there's a
-    corner case: when __module__ is __main__ (i.e. the callable is
-    defined in the same module as __main__).  In this case,
-    f.__module__ returns "__main__" instead of the file that it is
-    defined in.  Work around this using pathlib.Path (see below).
-
-    >>> function_identifier(function_identifier)
-    'unittest_utils:function_identifier'
-
-    """
-    if f.__module__ == '__main__':
-        from pathlib import Path
-        import __main__
-        module = __main__.__file__
-        module = Path(module).stem
-        return f'{module}:{f.__name__}'
-    else:
-        return f'{f.__module__}:{f.__name__}'
-
-
 def check_method_for_perf_regressions(func: Callable) -> Callable:
     """
     This is meant to be used on a method in a class that subclasses
@@ -191,8 +169,9 @@ def check_method_for_perf_regressions(func: Callable) -> Callable:
                 'Unknown/unexpected --unittests_persistance_strategy value'
             )
 
-        logger.debug(f'Watching {func.__name__}\'s performance...')
-        func_id = function_identifier(func)
+        func_id = function_utils.function_identifier(func)
+        func_name = func.__name__
+        logger.debug(f'Watching {func_name}\'s performance...')
         logger.debug(f'Canonical function identifier = {func_id}')
 
         try:
@@ -220,38 +199,40 @@ def check_method_for_perf_regressions(func: Callable) -> Callable:
         if len(hist) < config.config['unittests_num_perf_samples']:
             hist.append(run_time)
             logger.debug(
-                f'Still establishing a perf baseline for {func.__name__}'
+                f'Still establishing a perf baseline for {func_name}'
             )
         else:
             stdev = statistics.stdev(hist)
-            logger.debug(f'For {func.__name__}, performance stdev={stdev}')
+            logger.debug(f'For {func_name}, performance stdev={stdev}')
             slowest = hist[-1]
-            logger.debug(f'For {func.__name__}, slowest perf on record is {slowest:f}s')
+            logger.debug(f'For {func_name}, slowest perf on record is {slowest:f}s')
             limit = slowest + stdev * 4
             logger.debug(
-                f'For {func.__name__}, max acceptable runtime is {limit:f}s'
+                f'For {func_name}, max acceptable runtime is {limit:f}s'
             )
             logger.debug(
-                f'For {func.__name__}, actual observed runtime was {run_time:f}s'
+                f'For {func_name}, actual observed runtime was {run_time:f}s'
             )
             if (
                 run_time > limit and
                 not config.config['unittests_ignore_perf']
             ):
                 msg = f'''{func_id} performance has regressed unacceptably.
-{hist[-1]:f}s is the slowest record in {len(hist)} db perf samples.
-It just ran in {run_time:f}s which is >5 stdevs slower than the slowest sample.
+{slowest:f}s is the slowest runtime on record in {len(hist)} perf samples.
+It just ran in {run_time:f}s which is 4+ stdevs slower than the slowest.
 Here is the current, full db perf timing distribution:
 
 '''
                 for x in hist:
                     msg += f'{x:f}\n'
                 logger.error(msg)
-                slf = args[0]
-                slf.fail(msg)
+                slf = args[0]        # Peek at the wrapped function's self ref.
+                slf.fail(msg)        # ...to fail the testcase.
             else:
                 hist.append(run_time)
 
+        # Don't spam the database with samples; just pick a random
+        # sample from what we have and store that back.
         n = min(config.config['unittests_num_perf_samples'], len(hist))
         hist = random.sample(hist, n)
         hist.sort()
@@ -262,6 +243,18 @@ Here is the current, full db perf timing distribution:
 
 
 def check_all_methods_for_perf_regressions(prefix='test_'):
+    """Decorate unittests with this to pay attention to the perf of the
+    testcode and flag perf regressions.  e.g.
+
+    import unittest_utils as uu
+
+    @uu.check_all_methods_for_perf_regressions()
+    class TestMyClass(unittest.TestCase):
+
+        def test_some_part_of_my_class(self):
+            ...
+
+    """
     def decorate_the_testcase(cls):
         if issubclass(cls, unittest.TestCase):
             for name, m in inspect.getmembers(cls, inspect.isfunction):