fixup! feat(Window.split_window): set up environment

Author: zappolowski

src/libtmux/window.py

@@ -9,7 +9,7 @@
 import shlex
 import typing as t
 
-from libtmux.common import tmux_cmd
+from libtmux.common import has_gte_version, tmux_cmd
 from libtmux.pane import Pane
 
 from . import exc, formats
@@ -522,8 +522,13 @@ def split_window(
             tmux_args += ("-d",)
 
         if environment:
-            for k, v in environment.items():
-                tmux_args += ("-e%s=%s" % (k, v),)
+            if has_gte_version("3.0"):
+                for k, v in environment.items():
+                    tmux_args += ("-e%s=%s" % (k, v),)
+            else:
+                logger.warning(
+                    "Cannot set up environment as tmux 3.0 or newer is required."
+                )
 
         if shell:
             tmux_args += (shell,)

tests/test_window.py

@@ -314,6 +314,10 @@ def test_empty_window_name(session: Session) -> None:
     assert "''" in cmd.stdout
 
 
+@pytest.mark.skipif(
+    has_lt_version("3.0"),
+    reason="needs -e flag for split-window which was introduced in 3.0",
+)
 def test_split_window_with_environment(session: Session) -> None:
     env = shutil.which("env")
     assert env is not None, "Cannot find usable `env` in Path."
@@ -328,3 +332,25 @@ def test_split_window_with_environment(session: Session) -> None:
     time.sleep(0.05)
     pane.send_keys("echo $ENV_VAR")
     assert pane.capture_pane() == ["$ echo $ENV_VAR", "pane", "$"]
+
+
+@pytest.mark.skipif(
+    has_gte_version("3.0"),
+    reason="3.0 has the -e flag on split-window",
+)
+def test_split_window_with_environment_logs_warning_for_old_tmux(
+    session: Session,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    env = shutil.which("env")
+    assert env is not None, "Cannot find usable `env` in Path."
+
+    window = session.new_window(window_name="split_window_with_environment")
+    window.split_window(
+        shell=f"{env} PS1='$ ' bash --norc --noprofile",
+        environment={"ENV_VAR": "pane"},
+    )
+
+    assert any(
+        "Cannot set up environment" in record.msg for record in caplog.records
+    ), "Warning missing"