From 080d0e8471942acf37d2818604b1a01687cedd83 Mon Sep 17 00:00:00 2001
From: FBumann <117816358+FBumann@users.noreply.github.com>
Date: Tue, 2 Sep 2025 14:00:16 +0200
Subject: [PATCH 1/4] Improve assert_conequal

---
 tests/conftest.py | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/tests/conftest.py b/tests/conftest.py
index 5399be72a..4c483c2ca 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -457,10 +457,16 @@ def assert_conequal(actual: linopy.Constraint, desired: linopy.Constraint):
     except AssertionError as e:
         raise AssertionError(f"{name} left-hand sides don't match:\n{e}") from e
 
-    try:
-        linopy.testing.assert_linequal(actual.rhs, desired.rhs)
-    except AssertionError as e:
-        raise AssertionError(f"{name} right-hand sides don't match:\n{e}") from e
+    if isinstance(actual.rhs, xr.DataArray):
+        try:
+            xr.testing.assert_equal(actual.rhs, desired.rhs)
+        except AssertionError as e:
+            raise AssertionError(f"{name} right-hand sides don't match:\n{e}") from e
+    else:
+        try:
+            linopy.testing.assert_linequal(actual.rhs, desired.rhs)
+        except AssertionError as e:
+            raise AssertionError(f"{name} right-hand sides don't match:\n{e}") from e
 
     try:
         xr.testing.assert_equal(actual.sign, desired.sign)

From a8b748140a1edfb58c326c12efd552c70e604799 Mon Sep 17 00:00:00 2001
From: FBumann <117816358+FBumann@users.noreply.github.com>
Date: Tue, 2 Sep 2025 20:06:27 +0200
Subject: [PATCH 2/4] Improve assert_conequal and fix linopy dependency

---
 pyproject.toml    | 2 +-
 tests/conftest.py | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index 8c846dc03..4624d3a00 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -38,7 +38,7 @@ dependencies = [
     "pandas >= 2.0.0, < 3",
 
     # Optimization and data handling
-    "linopy >= 0.5.1, < 0.6.0",
+    "linopy >= 0.5.1, < 0.5.6",  # Update and test regularly
     "netcdf4 >= 1.6.1, < 2",
 
     # Utilities
diff --git a/tests/conftest.py b/tests/conftest.py
index 4c483c2ca..fbab7a388 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -457,14 +457,14 @@ def assert_conequal(actual: linopy.Constraint, desired: linopy.Constraint):
     except AssertionError as e:
         raise AssertionError(f"{name} left-hand sides don't match:\n{e}") from e
 
-    if isinstance(actual.rhs, xr.DataArray):
+    if isinstance(actual.rhs, linopy.Constraint):
         try:
-            xr.testing.assert_equal(actual.rhs, desired.rhs)
+            linopy.testing.assert_linequal(actual.rhs, desired.rhs)
         except AssertionError as e:
             raise AssertionError(f"{name} right-hand sides don't match:\n{e}") from e
     else:
         try:
-            linopy.testing.assert_linequal(actual.rhs, desired.rhs)
+            xr.testing.assert_equal(actual.rhs, desired.rhs)
         except AssertionError as e:
             raise AssertionError(f"{name} right-hand sides don't match:\n{e}") from e
 

From 19757efd1db25b74816db818a665c67790c5b83b Mon Sep 17 00:00:00 2001
From: FBumann <117816358+FBumann@users.noreply.github.com>
Date: Tue, 2 Sep 2025 21:25:37 +0200
Subject: [PATCH 3/4] Improve assert_conequal and fix linopy dependency

---
 CHANGELOG.md      |  3 +++
 tests/conftest.py | 21 +++++++--------------
 2 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6232a61f7..94ea53017 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Deprecated
 - For the classes `Sink`, `Source` and `SourceAndSink`: `.sink`, `.source` and `.prevent_simultaneous_sink_and_source` are deprecated in favor of the new arguments `inputs`, `outputs` and `prevent_simultaneous_flow_rates`.
 
+### Fixed
+- Fixed testing issue with new `linopy` version 0.5.6
+
 ## [2.1.5] - 2025-07-08
 
 ### Fixed
diff --git a/tests/conftest.py b/tests/conftest.py
index fbab7a388..c8d2e5606 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -450,28 +450,21 @@ def basic_flow_system_linopy(timesteps_linopy) -> fx.FlowSystem:
 
 def assert_conequal(actual: linopy.Constraint, desired: linopy.Constraint):
     """Assert that two constraints are equal with detailed error messages."""
-    name = actual.name
 
     try:
         linopy.testing.assert_linequal(actual.lhs, desired.lhs)
     except AssertionError as e:
-        raise AssertionError(f"{name} left-hand sides don't match:\n{e}") from e
-
-    if isinstance(actual.rhs, linopy.Constraint):
-        try:
-            linopy.testing.assert_linequal(actual.rhs, desired.rhs)
-        except AssertionError as e:
-            raise AssertionError(f"{name} right-hand sides don't match:\n{e}") from e
-    else:
-        try:
-            xr.testing.assert_equal(actual.rhs, desired.rhs)
-        except AssertionError as e:
-            raise AssertionError(f"{name} right-hand sides don't match:\n{e}") from e
+        raise AssertionError(f"{actual.name} left-hand sides don't match:\n{e}") from e
 
     try:
         xr.testing.assert_equal(actual.sign, desired.sign)
     except AssertionError as e:
-        raise AssertionError(f"{name} signs don't match:\nActual: {actual.sign}\nExpected: {desired.sign}") from e
+        raise AssertionError(f"{actual.name} signs don't match:\n{e}") from e
+
+    try:
+        xr.testing.assert_equal(actual.rhs, desired.rhs)
+    except AssertionError as e:
+        raise AssertionError(f"{actual.name} right-hand sides don't match:\n{e}") from e
 
 
 def assert_var_equal(actual: linopy.Variable, desired: linopy.Variable):

From 6bfe8ef601a53b6a4e5bdf9aeebdb315d7752b58 Mon Sep 17 00:00:00 2001
From: FBumann <117816358+FBumann@users.noreply.github.com>
Date: Tue, 2 Sep 2025 21:30:28 +0200
Subject: [PATCH 4/4] Improce CHANGELOG.md

---
 CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 94ea53017..f689f5121 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,7 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - For the classes `Sink`, `Source` and `SourceAndSink`: `.sink`, `.source` and `.prevent_simultaneous_sink_and_source` are deprecated in favor of the new arguments `inputs`, `outputs` and `prevent_simultaneous_flow_rates`.
 
 ### Fixed
-- Fixed testing issue with new `linopy` version 0.5.6
+- Fixed testing issue with new `linopy` version 0.5.6 [[#296](https://github.com/PyPSA/linopy/pull/296) by [@FBumann](https://github.com/FBumann)]
 
 ## [2.1.5] - 2025-07-08