From c4e841c28a7781f170906350f7299c8f4d0e385c Mon Sep 17 00:00:00 2001
From: Fabian Zills <46721498+PythonFZ@users.noreply.github.com>
Date: Fri, 18 Oct 2024 15:30:04 +0200
Subject: [PATCH] support empty groups (#115)

* support empty groups

* bump version test

* add url
---
 pyproject.toml            |  5 ++++-
 tests/test_graph_group.py | 21 +++++++++++++++++++++
 tests/test_znflow.py      |  2 +-
 znflow/graph.py           |  2 +-
 4 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index 6a8feb5..8f5549d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,11 +1,14 @@
 [tool.poetry]
 name = "znflow"
-version = "0.2.1"
+version = "0.2.2"
 description = "A general purpose framework for building and running computational graphs."
 authors = ["zincwarecode <zincwarecode@gmail.com>"]
 license = "Apache-2.0"
 readme = "README.md"
 
+[tool.poetry.urls]
+repository = "https://github.com/zincware/znflow"
+
 [tool.poetry.dependencies]
 python = ">=3.9,<4.0"
 networkx = "^3"
diff --git a/tests/test_graph_group.py b/tests/test_graph_group.py
index 7d285f0..4b37c58 100644
--- a/tests/test_graph_group.py
+++ b/tests/test_graph_group.py
@@ -276,3 +276,24 @@ def test_grp_nodes():
     assert grp.nodes == [n1, n2]
     assert grp.uuids == [n1.uuid, n2.uuid]
     assert grp.names == ("grp1",)
+
+
+def test_empty_grps():
+    graph = znflow.DiGraph()
+
+    with graph.group("grp1") as grp1:
+        pass
+    with graph.group("grp2") as grp2:
+        pass
+
+    assert len(grp1) == 0
+    assert len(grp2) == 0
+    assert grp1.uuids == []
+    assert grp2.uuids == []
+
+    assert grp1.names == ("grp1",)
+    assert grp2.names == ("grp2",)
+
+    assert len(graph.groups) == 2
+    assert grp1.names in graph.groups
+    assert grp2.names in graph.groups
diff --git a/tests/test_znflow.py b/tests/test_znflow.py
index 85dabc2..314bec9 100644
--- a/tests/test_znflow.py
+++ b/tests/test_znflow.py
@@ -5,4 +5,4 @@
 
 def test_version():
     """Test the version."""
-    assert znflow.__version__ == "0.2.1"
+    assert znflow.__version__ == "0.2.2"
diff --git a/znflow/graph.py b/znflow/graph.py
index b4de400..ee155df 100644
--- a/znflow/graph.py
+++ b/znflow/graph.py
@@ -247,9 +247,9 @@ def group(self, *names: str) -> typing.Generator[Group, None, None]:
         group = self.groups.get(names, Group(names=names, uuids=[], graph=self))
 
         def finalize_group():
+            self.groups[group.names] = group
             for node_uuid in self.nodes:
                 if node_uuid not in existing_nodes:
-                    self.groups[group.names] = group
                     group.uuids.append(node_uuid)
 
         try: