feat: Allow skipping of validation when combining workspaces (#2385)

* Add validate arg to workspace.combine to allow for optionally skipping
  workspace validation during. Default is to validate.
* Add test for validate arg being used.
* Add Lorenz Gaertner to contributors list.

Author: lorenzennio

docs/contributors.rst

@@ -33,3 +33,4 @@ Contributors include:
 - Beojan Stanislaus
 - Daniel Werner
 - Jonas Rembser
+- Lorenz Gaertner

src/pyhf/workspace.py

@@ -706,7 +706,9 @@ def rename(self, modifiers=None, samples=None, channels=None, measurements=None)
         )
 
     @classmethod
-    def combine(cls, left, right, join='none', merge_channels=False):
+    def combine(
+        cls, left, right, join='none', merge_channels=False, validate: bool = True
+    ):
         """
         Return a new workspace specification that is the combination of the two workspaces.
 
@@ -733,6 +735,7 @@ def combine(cls, left, right, join='none', merge_channels=False):
             right (~pyhf.workspace.Workspace): Another workspace
             join (:obj:`str`): How to join the two workspaces. Pick from "none", "outer", "left outer", or "right outer".
             merge_channels (:obj:`bool`): Whether or not to merge channels when performing the combine. This is only done with "outer", "left outer", and "right outer" options.
+            validate (:obj:`bool`): Whether to validate against a JSON schema.
 
         Returns:
             ~pyhf.workspace.Workspace: A new combined workspace object
@@ -770,7 +773,7 @@ def combine(cls, left, right, join='none', merge_channels=False):
             'observations': new_observations,
             'version': new_version,
         }
-        return cls(newspec)
+        return cls(newspec, validate=validate)
 
     @classmethod
     def sorted(cls, workspace):

tests/test_workspace.py

@@ -791,6 +791,28 @@ def test_combine_workspace(workspace_factory, join):
     )
 
 
+@pytest.mark.parametrize("join", pyhf.Workspace.valid_joins)
+def test_combine_workspace_without_validation(mocker, workspace_factory, join):
+    ws = workspace_factory()
+    new_ws = ws.rename(
+        channels={channel: f"renamed_{channel}" for channel in ws.channels},
+        samples={sample: f"renamed_{sample}" for sample in ws.samples},
+        modifiers={
+            modifier: f"renamed_{modifier}"
+            for modifier, _ in ws.modifiers
+            if modifier != "lumi"
+        },
+        measurements={
+            measurement: f"renamed_{measurement}"
+            for measurement in ws.measurement_names
+        },
+    )
+
+    mocker.patch("pyhf.schema.validate")
+    pyhf.Workspace.combine(ws, new_ws, join=join, validate=False)
+    assert pyhf.schema.validate.called is False
+
+
 def test_workspace_equality(workspace_factory):
     ws = workspace_factory()
     ws_other = workspace_factory()