Split init / exec of tmux_cmd for debuggability

libtmux/common.py

@@ -147,8 +147,7 @@ def show_environment(self, name=None):
         return vars_dict
 
 
-class tmux_cmd:
-
+class TmuxCommand:
     """
     :term:`tmux(1)` command via :py:mod:`subprocess`.
 
@@ -165,7 +164,12 @@ class tmux_cmd:
 
     .. code-block:: python
 
-        proc = tmux_cmd('new-session', '-s%' % 'my session')
+        c = tmux_cmd('new-session', '-s%' % 'my session')
+
+        # You can actually see the command in the .cmd attribute
+        print(c.cmd)
+
+        proc = c.execute()
 
         if proc.stderr:
             raise exc.LibTmuxException(
@@ -183,8 +187,8 @@ class tmux_cmd:
     Notes
     -----
 
-    .. versionchanged:: 0.8
-        Renamed from ``tmux`` to ``tmux_cmd``.
+    .. versionadded:: 0.8.4
+        Wrap to split execution from command from instance of it
     """
 
     def __init__(self, *args, **kwargs):
@@ -205,6 +209,8 @@ def __init__(self, *args, **kwargs):
 
         self.cmd = cmd
 
+    def execute(self):
+        cmd = self.cmd
         try:
             self.process = subprocess.Popen(
                 cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE
@@ -229,6 +235,39 @@ def __init__(self, *args, **kwargs):
                 self.stdout = self.stderr[0]
 
         logger.debug("self.stdout for {}: \n{}".format(" ".join(cmd), self.stdout))
+        return self
+
+
+def tmux_cmd(*args, **kwargs):
+    """Wrapper around TmuxCommand. Executes instantly.
+
+    Examples
+    --------
+
+    .. code-block:: python
+
+        proc = tmux_cmd('new-session', '-s%' % 'my session')
+
+        if proc.stderr:
+            raise exc.LibTmuxException(
+                'Command: %s returned error: %s' % (proc.cmd, proc.stderr)
+            )
+
+        print('tmux command returned %s' % proc.stdout)
+
+    Equivalent to:
+
+    .. code-block:: bash
+
+        $ tmux new-session -s my session
+
+    Notes
+    -----
+
+    .. versionchanged:: 0.8
+        Renamed from ``tmux`` to ``tmux_cmd``.
+    """
+    return TmuxCommand(*args, **kwargs).execute()
 
 
 class TmuxMappingObject(MutableMapping):

libtmux/server.py

@@ -13,11 +13,11 @@
     EnvironmentMixin,
     PaneDict,
     SessionDict,
+    TmuxCommand,
     TmuxRelationalObject,
     WindowDict,
     has_gte_version,
     session_check_name,
-    tmux_cmd,
 )
 from .session import Session
 
@@ -127,7 +127,7 @@ def cmd(self, *args, **kwargs):
             else:
                 raise ValueError("Server.colors must equal 88 or 256")
 
-        return tmux_cmd(*args, **kwargs)
+        return TmuxCommand(*args, **kwargs).execute()
 
     def _list_sessions(self) -> t.List[SessionDict]:
         """
@@ -136,7 +136,7 @@ def _list_sessions(self) -> t.List[SessionDict]:
         Retrieved from ``$ tmux(1) list-sessions`` stdout.
 
         The :py:obj:`list` is derived from ``stdout`` in
-        :class:`common.tmux_cmd` which wraps :py:class:`subprocess.Popen`.
+        :class:`common.TmuxCommand` which wraps :py:class:`subprocess.Popen`.
 
         Returns
         -------
@@ -199,7 +199,7 @@ def _list_windows(self) -> t.List[WindowDict]:
         Retrieved from ``$ tmux(1) list-windows`` stdout.
 
         The :py:obj:`list` is derived from ``stdout`` in
-        :class:`common.tmux_cmd` which wraps :py:class:`subprocess.Popen`.
+        :class:`common.TmuxCommand` which wraps :py:class:`subprocess.Popen`.
 
         Returns
         -------
@@ -261,7 +261,7 @@ def _list_panes(self) -> t.List[PaneDict]:
         Retrieved from ``$ tmux(1) list-panes`` stdout.
 
         The :py:obj:`list` is derived from ``stdout`` in
-        :class:`util.tmux_cmd` which wraps :py:class:`subprocess.Popen`.
+        :class:`util.TmuxCommand` which wraps :py:class:`subprocess.Popen`.
 
         Returns
         -------

tests/test_common.py

@@ -27,15 +27,28 @@
 version_regex = re.compile(r"([0-9]\.[0-9])|(master)")
 
 
-def test_allows_master_version(monkeypatch):
-    def mock_tmux_cmd(param):
+@pytest.mark.parametrize("executor", ["mock_tmux_cmd", "mock_TmuxCommand"])
+def test_allows_master_version(monkeypatch, executor):
+    def mock_TmuxCommand(param):
         class Hi:
             stdout = ["tmux master"]
             stderr = None
 
+            def execute(self):
+                return self
+
         return Hi()
 
-    monkeypatch.setattr(libtmux.common, "tmux_cmd", mock_tmux_cmd)
+    def mock_tmux_cmd(param):
+        class Hi(object):
+            stdout = ["tmux master"]
+            stderr = None
+
+        return Hi()
+
+    mock_cmd = locals()[executor]
+
+    monkeypatch.setattr(libtmux.common, "tmux_cmd", mock_cmd)
 
     assert has_minimum_version()
     assert has_gte_version(TMUX_MIN_VERSION)
@@ -51,6 +64,9 @@ class Hi:
             stdout = ["tmux next-2.9"]
             stderr = None
 
+            def execute(self):
+                return self
+
         return Hi()
 
     monkeypatch.setattr(libtmux.common, "tmux_cmd", mock_tmux_cmd)
@@ -66,6 +82,9 @@ def mock_tmux_cmd(param):
         class Hi:
             stderr = ["tmux: unknown option -- V"]
 
+            def execute(self):
+                return self
+
         return Hi()
 
     monkeypatch.setattr(libtmux.common, "tmux_cmd", mock_tmux_cmd)
@@ -83,6 +102,9 @@ def mock_tmux_cmd(param):
         class Hi:
             stderr = ["tmux: unknown option -- V"]
 
+            def execute(self):
+                return self
+
         return Hi()
 
     monkeypatch.setattr(libtmux.common, "tmux_cmd", mock_tmux_cmd)
@@ -183,6 +205,12 @@ def test_tmux_cmd_unicode(session):
     session.cmd("new-window", "-t", 3, "-n", "юникод", "-F", "Ελληνικά")
 
 
+def test_tmux_cmd_makes_cmd_available():
+    """tmux_cmd objects should make .cmd attribute available."""
+    command = tmux_cmd("-V")
+    assert hasattr(command, "cmd")
+
+
 @pytest.mark.parametrize(
     "session_name,raises,exc_msg_regex",
     [