From a1635276389c43a431cbc194920f88dedea0425f Mon Sep 17 00:00:00 2001
From: zweihuehner <2huehner@gmail.com>
Date: Sun, 15 Mar 2026 13:54:38 +0000
Subject: [PATCH 1/4] make test_create_decode more specific

---
 tests/test_graph_creation.py | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/tests/test_graph_creation.py b/tests/test_graph_creation.py
index b45d486..2c2d0a4 100644
--- a/tests/test_graph_creation.py
+++ b/tests/test_graph_creation.py
@@ -197,8 +197,8 @@ def test_create_lat_lon(kind):
 @pytest.mark.parametrize("kind", ["graphcast", "keisler", "oskarsson_hierarchical"])
 def test_create_decode_mask(kind):
     """
-    Tests that the decode mask for m2g works, resulting in less edges than
-    no filtering.
+    Tests that the decode mask for m2g works, resulting in less m2g edges than
+    without decode mask.
     """
     xy = test_utils.create_fake_irregular_coords(100)
     fn_name = f"create_{kind}_graph"
@@ -214,8 +214,16 @@ def test_create_decode_mask(kind):
         coords=xy, mesh_node_distance=mesh_node_distance, decode_mask=decode_mask
     )
 
-    # Check that some filtering has been performed
-    assert len(filtered_graph.edges) < len(unfiltered_graph.edges)
+    # Check that m2g edges (mesh-to-grid / decoding edges) are filtered
+    unfiltered_m2g_edges = [
+        e for e in unfiltered_graph.edges(data=True) if e[2].get("component") == "m2g"
+    ]
+    filtered_m2g_edges = [
+        e for e in filtered_graph.edges(data=True) if e[2].get("component") == "m2g"
+    ]
+    print(len(unfiltered_m2g_edges))
+    print(len(filtered_m2g_edges))
+    assert len(filtered_m2g_edges) < len(unfiltered_m2g_edges)
 
 
 @pytest.mark.parametrize("kind", ["graphcast", "oskarsson_hierarchical"])

From 3169656ce8cea546fda54881c2811666b1204687 Mon Sep 17 00:00:00 2001
From: zweihuehner <2huehner@gmail.com>
Date: Sun, 15 Mar 2026 14:15:53 +0000
Subject: [PATCH 2/4] update changelog

---
 CHANGELOG.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6cf3ab0..5223180 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Add `__version__` attribute to the package init
   [\#56](https://github.com/mllam/weather-model-graphs/pull/56) @AdMub
 
+### Changed
+
+- Make `test_create_decode_mask` more specific and future-proof by checking only m2g (decoding) edges instead of total edges. [\#104](https://github.com/mllam/weather-model-graphs/pull/104) @zweihuehner
+
 ## [v0.3.0](https://github.com/mllam/weather-model-graphs/releases/tag/v0.3.0)
 
 

From d656c58188c3f65c4f7f2d50639567c16b9bfcfb Mon Sep 17 00:00:00 2001
From: zweihuehner <2huehner@gmail.com>
Date: Sun, 15 Mar 2026 14:18:35 +0000
Subject: [PATCH 3/4] remove print statments

---
 tests/test_graph_creation.py | 2 --
 1 file changed, 2 deletions(-)

diff --git a/tests/test_graph_creation.py b/tests/test_graph_creation.py
index 2c2d0a4..f57a8f4 100644
--- a/tests/test_graph_creation.py
+++ b/tests/test_graph_creation.py
@@ -221,8 +221,6 @@ def test_create_decode_mask(kind):
     filtered_m2g_edges = [
         e for e in filtered_graph.edges(data=True) if e[2].get("component") == "m2g"
     ]
-    print(len(unfiltered_m2g_edges))
-    print(len(filtered_m2g_edges))
     assert len(filtered_m2g_edges) < len(unfiltered_m2g_edges)
 
 

From 21dc99d206e3473c1d60dd29d5af53d5505ebf11 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Faro=20Sch=C3=A4fer?=
 <58438715+zweihuehner@users.noreply.github.com>
Date: Sat, 21 Mar 2026 23:03:20 +0100
Subject: [PATCH 4/4] Apply suggestion from @Copilot

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
---
 tests/test_graph_creation.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/test_graph_creation.py b/tests/test_graph_creation.py
index f57a8f4..9b72759 100644
--- a/tests/test_graph_creation.py
+++ b/tests/test_graph_creation.py
@@ -197,8 +197,8 @@ def test_create_lat_lon(kind):
 @pytest.mark.parametrize("kind", ["graphcast", "keisler", "oskarsson_hierarchical"])
 def test_create_decode_mask(kind):
     """
-    Tests that the decode mask for m2g works, resulting in less m2g edges than
-    without decode mask.
+    Tests that the decode mask for m2g works, resulting in fewer m2g edges than
+    without a decode mask.
     """
     xy = test_utils.create_fake_irregular_coords(100)
     fn_name = f"create_{kind}_graph"