From 66c4baeabba39f063f4998917609c3705c3148ab Mon Sep 17 00:00:00 2001
From: Michael Skinner <git@mcskinner.com>
Date: Sun, 19 Apr 2020 18:38:14 -0700
Subject: [PATCH 1/2] alternative API for `multi_check` to allow parameterless
 checks, using *args

---
 bulwark/checks.py     | 23 ++++++++++++++++------
 bulwark/decorators.py | 27 +++++++++++++++++++++++++
 tests/test_checks.py  | 46 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 90 insertions(+), 6 deletions(-)

diff --git a/bulwark/checks.py b/bulwark/checks.py
index 6c83484..f5f70be 100644
--- a/bulwark/checks.py
+++ b/bulwark/checks.py
@@ -7,6 +7,7 @@
 - return the original, unaltered pd.DataFrame
 
 """
+import collections
 import warnings
 
 import numpy as np
@@ -477,22 +478,32 @@ def is_same_as(df, df_to_compare, **kwargs):
     return df
 
 
-def multi_check(df, checks, warn=False):
+def multi_check(df, checks, *more_checks, warn=False):
     """Asserts that all checks pass.
-
     Args:
         df (pd.DataFrame): Any pd.DataFrame.
-        checks (dict): Mapping of check functions to parameters for those check functions.
+        checks: A single function specification, as below.
+                This exists for backwards compatibility, and to ensure there's at least one check.
+        more_checks: Any number of check function specifications.
+                     The simplest specification is a check function, which assumes no parameters.
+                     Or it may be a Mapping of check functions to parameters for those functions.
+                     In the event of duplicates, the last specification will win.
         warn (bool): Indicates whether an error should be raised
                      or only a warning notification should be displayed.
                      Default is to error.
-
     Returns:
         Original `df`.
-
     """
+
+    checks_map = {}
+    for check in [checks, *more_checks]:
+        if isinstance(check, collections.Mapping):
+            checks_map.update(check)
+        else:
+            checks_map[check] = {}
+
     error_msgs = []
-    for func, params in checks.items():
+    for func, params in checks_map.items():
         try:
             func(df, **params)
         except AssertionError as e:
diff --git a/bulwark/decorators.py b/bulwark/decorators.py
index 4718a05..66f8708 100644
--- a/bulwark/decorators.py
+++ b/bulwark/decorators.py
@@ -45,6 +45,33 @@ class decorator_name(BaseDecorator):
     setattr(this_module, decorator_name, decorator_factory(decorator_name, func))
 
 
+class MultiCheck:
+    """
+    Notes:
+        - This code is purposefully located below the auto-generation of decorators,
+          so this overwrites the auto-generated MultiCheck.
+        - `MultiCheck`'s __init__ diverges from `BaseDecorator`, due to the use of *args.
+
+    TODO: Work this into BaseDecorator?
+
+    """
+
+    def __init__(self, checks, *more_checks, warn=False, enabled=True):
+        self.checks = checks
+        self.more_checks = more_checks
+        self.warn = warn
+        self.enabled = enabled
+
+    def __call__(self, f):
+        @functools.wraps(f)
+        def decorated(*args, **kwargs):
+            df = f(*args, **kwargs)
+            if self.enabled:
+                ck.multi_check(df, self.checks, *self.more_checks, warn=self.warn)
+            return df
+        return decorated
+
+
 class CustomCheck:
     """
     Notes:
diff --git a/tests/test_checks.py b/tests/test_checks.py
index c1707b6..b0c1690 100644
--- a/tests/test_checks.py
+++ b/tests/test_checks.py
@@ -515,6 +515,52 @@ def total_sum_not_equal(df, amt):
     # with pytest.raises(AssertionError):
 
 
+def test_multi_check_varargs():
+    df = pd.DataFrame({"a": [1, 2, 3], "b": [4, 5, 6]})
+    result = ck.multi_check(df, ck.has_no_nans, warn=False)
+    tm.assert_frame_equal(df, result)
+
+    result = ck.multi_check(df,
+                            ck.has_no_nans,
+                            {ck.is_shape: {"shape": (3, 2)}},
+                            warn=False)
+    tm.assert_frame_equal(df, result)
+
+    result = dc.MultiCheck(ck.has_no_nans,
+                           {ck.is_shape: {"shape": (3, 2)}},
+                           warn=False)(_noop)(df)
+    tm.assert_frame_equal(df, result)
+
+    def total_sum_not_equal(df, amt):
+        if amt == 51:
+            raise AssertionError("Test")
+        return True
+
+    result = ck.multi_check(df,
+                            ck.has_no_nans,
+                            {total_sum_not_equal: {"amt": 52}},
+                            warn=False)
+    tm.assert_frame_equal(df, result)
+
+    result = dc.MultiCheck(ck.has_no_nans,
+                           {total_sum_not_equal: {"amt": 52}},
+                           warn=False)(_noop)(df)
+    tm.assert_frame_equal(df, result)
+
+    result = dc.MultiCheck(ck.has_no_nans,
+                           {total_sum_not_equal: {"amt": 51}},
+                           {total_sum_not_equal: {"amt": 52}},  # last wins
+                           warn=False)(_noop)(df)
+    tm.assert_frame_equal(df, result)
+
+    with pytest.raises(AssertionError):
+        result = dc.MultiCheck(ck.has_no_nans,
+                               {total_sum_not_equal: {"amt": 51}},
+                               warn=False)(_noop)(df)
+
+    # with pytest.raises(AssertionError):
+
+
 def test_custom_check():
     def f(df, length):
         if len(df) <= length:

From b983765ce4e2f0f0f0bcc9ba48fa10527605b1b0 Mon Sep 17 00:00:00 2001
From: Michael Skinner <git@mcskinner.com>
Date: Sun, 19 Apr 2020 18:41:07 -0700
Subject: [PATCH 2/2] fix some whitespace oddness

---
 bulwark/checks.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/bulwark/checks.py b/bulwark/checks.py
index f5f70be..53988aa 100644
--- a/bulwark/checks.py
+++ b/bulwark/checks.py
@@ -491,8 +491,10 @@ def multi_check(df, checks, *more_checks, warn=False):
         warn (bool): Indicates whether an error should be raised
                      or only a warning notification should be displayed.
                      Default is to error.
+
     Returns:
         Original `df`.
+
     """
 
     checks_map = {}