From 9c6bbac7ef09213dd0e6523f30eb328716015d14 Mon Sep 17 00:00:00 2001
From: Tin Lai <tin@tinyiu.com>
Date: Sun, 21 Jul 2024 19:14:05 +1000
Subject: [PATCH 01/10] implements if conditions for pane and window

Signed-off-by: Tin Lai <tin@tinyiu.com>
---
 src/tmuxp/workspace/loader.py | 60 +++++++++++++++++++++++++++++++----
 1 file changed, 53 insertions(+), 7 deletions(-)

diff --git a/src/tmuxp/workspace/loader.py b/src/tmuxp/workspace/loader.py
index 58da0ee91a..2e616e8670 100644
--- a/src/tmuxp/workspace/loader.py
+++ b/src/tmuxp/workspace/loader.py
@@ -8,6 +8,49 @@
 logger = logging.getLogger(__name__)
 
 
+def optional_windows_and_pane(
+    workspace_dict: t.Dict[str, t.Any],
+) -> bool:
+    """Determine if a window or pane should be included based on `if` conditions.
+
+    The function evaluates the 'if' condition specified in `workspace_dict` to determine inclusion:
+    - If 'if' key is not present, it defaults to True.
+    - If 'if' is a string or boolean, it's treated as a shell variable.
+    - 'if' can be a dictionary containing 'shell' or 'python' keys with valid expressions.
+    - 'shell' expressions are expanded and checked against true values ('y', 'yes', '1', 'on', 'true', 't').
+    - 'python' expressions are evaluated using `eval()`
+
+    Parameters
+    ----------
+    workspace_dict : Dict
+        A dictionary containing pane/window configuration data.
+
+    Returns
+    -------
+    bool
+        True if the window or pane should be included, False otherwise.
+    """
+    if "if" not in workspace_dict:
+        return True
+    if_cond = workspace_dict["if"]
+    if isinstance(if_cond, (str, bool)):
+        # treat this as shell variable
+        if_cond = {"shell": if_cond}
+    if not isinstance(if_cond, dict) or not ("shell" in if_cond or "python" in if_cond):
+        raise ValueError(f"if conditions does not contains valid expression: {if_cond}")
+    if "shell" in if_cond:
+        if isinstance(if_cond["shell"], str):
+            if expandshell(if_cond["shell"]).lower() not in ("y", "yes", "1", "on", "true", "t"):
+                return False
+        elif isinstance(if_cond["shell"], bool):
+            if not if_cond["shell"]:
+                return False
+    if "python" in if_cond:
+        if if_cond["python"] and not eval(if_cond["python"]):  # dangerous
+            return False
+    return True
+
+
 def expandshell(value: str) -> str:
     """Resolve shell variables based on user's ``$HOME`` and ``env``.
 
@@ -170,18 +213,21 @@ def expand(
 
     # recurse into window and pane workspace items
     if "windows" in workspace_dict:
-        workspace_dict["windows"] = [
-            expand(window, parent=workspace_dict)
-            for window in workspace_dict["windows"]
-        ]
+        window_dicts = workspace_dict["windows"]
+        window_dicts = filter(optional_windows_and_pane, window_dicts)
+        window_dicts = map(lambda x: expand(x, parent=workspace_dict), window_dicts)
+        # remove windows that has no panels (e.g. due to if conditions)
+        window_dicts = filter(lambda x: len(x["panes"]), window_dicts)
+        workspace_dict["windows"] = list(window_dicts)
+
     elif "panes" in workspace_dict:
         pane_dicts = workspace_dict["panes"]
         for pane_idx, pane_dict in enumerate(pane_dicts):
             pane_dicts[pane_idx] = {}
             pane_dicts[pane_idx].update(expand_cmd(pane_dict))
-        workspace_dict["panes"] = [
-            expand(pane, parent=workspace_dict) for pane in pane_dicts
-        ]
+        pane_dicts = filter(optional_windows_and_pane, pane_dicts)
+        pane_dicts = map(lambda x: expand(x, parent=workspace_dict), pane_dicts)
+        workspace_dict["panes"] = list(pane_dicts)
 
     return workspace_dict
 

From f9d1f4d6ec70658c997330ef5bb8f20b172eb0f5 Mon Sep 17 00:00:00 2001
From: Tin Lai <tin@tinyiu.com>
Date: Sun, 21 Jul 2024 19:46:08 +1000
Subject: [PATCH 02/10] add workspace provided envars when not presents in
 current environ

Signed-off-by: Tin Lai <tin@tinyiu.com>
---
 src/tmuxp/workspace/loader.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/tmuxp/workspace/loader.py b/src/tmuxp/workspace/loader.py
index 2e616e8670..dfd5496625 100644
--- a/src/tmuxp/workspace/loader.py
+++ b/src/tmuxp/workspace/loader.py
@@ -157,6 +157,9 @@ def expand(
             if any(val.startswith(a) for a in [".", "./"]):
                 val = str(cwd / val)
             workspace_dict["environment"][key] = val
+            if key not in os.environ:
+                # using user provided environment variable as default vars
+                os.environ[key] = val
     if "global_options" in workspace_dict:
         for key in workspace_dict["global_options"]:
             val = workspace_dict["global_options"][key]

From a886b7f45ce047bdd6535133856080e7ac3014f2 Mon Sep 17 00:00:00 2001
From: Tin Lai <tin@tinyiu.com>
Date: Sun, 21 Jul 2024 19:46:20 +1000
Subject: [PATCH 03/10] add docs

Signed-off-by: Tin Lai <tin@tinyiu.com>
---
 docs/configuration/examples.md | 35 ++++++++++++++++++++++++
 examples/if-conditions.json    | 49 ++++++++++++++++++++++++++++++++++
 examples/if-conditions.yaml    | 29 ++++++++++++++++++++
 3 files changed, 113 insertions(+)
 create mode 100644 examples/if-conditions.json
 create mode 100644 examples/if-conditions.yaml

diff --git a/docs/configuration/examples.md b/docs/configuration/examples.md
index 010b039c17..17ab54f56e 100644
--- a/docs/configuration/examples.md
+++ b/docs/configuration/examples.md
@@ -287,6 +287,41 @@ newer and tmux 3.0 or newer.
 
 ````
 
+## `if` conditions
+
+tmuxp enables one to optionally open windows / panes based on coditions. The `if` conditions can appears in the configuration for window or pane.
+
+````{tab} YAML
+
+```{literalinclude} ../../examples/if-conditions.yaml
+:language: yaml
+
+```
+````
+
+````{tab} JSON
+
+```{literalinclude} ../../examples/if-conditions.json
+:language: json
+
+```
+
+````
+
+In the example, running the example
+
+```console
+$ tmuxp load examples/if-conditions.yaml
+```
+
+should produce **only** a window with upper and lower split panes (others should have `if` conditions that evaluates to false). This example allows for on-demand pane showing, where
+
+```console
+$ show_htop=false tmuxp load examples/if-conditions.yaml
+```
+
+will insteads suppress the `htop` command pane and resulting in a different behaviour.
+
 ## Focusing
 
 tmuxp allows `focus: true` for assuring windows and panes are attached /
diff --git a/examples/if-conditions.json b/examples/if-conditions.json
new file mode 100644
index 0000000000..1765326243
--- /dev/null
+++ b/examples/if-conditions.json
@@ -0,0 +1,49 @@
+{
+  "session_name": "if conditions test",
+  "environment": {
+    "Foo": "false",
+    "show_htop": "true"
+  },
+  "windows": [
+    {
+      "window_name": "window 1 ${ha} $Foo",
+      "if": {
+        "shell": "${Foo}"
+      },
+      "panes": [
+        {
+          "shell_command": [
+            "echo \"this shouldn't shows up\""
+          ]
+        },
+        "echo neither should this $Foo"
+      ]
+    },
+    {
+      "window_name": "window 2",
+      "panes": [
+        {
+          "if": {
+            "python": "1+1==3"
+          },
+          "shell_command": [
+            "echo the above is a false statement"
+          ]
+        },
+        {
+          "shell_command": [
+            "echo no condition",
+            "python -m http.server"
+          ]
+        },
+        {
+          "if": "${show_htop}",
+          "shell_command": [
+            "echo the above is a true statement (by default), but can be disabled on-demand",
+            "htop"
+          ]
+        }
+      ]
+    }
+  ]
+}
\ No newline at end of file
diff --git a/examples/if-conditions.yaml b/examples/if-conditions.yaml
new file mode 100644
index 0000000000..425aec4325
--- /dev/null
+++ b/examples/if-conditions.yaml
@@ -0,0 +1,29 @@
+session_name: if conditions test
+environment:
+  Foo: 'false'
+  show_htop: 'true'
+windows:
+  # the following would not shows up as it evaluates to false
+  - window_name: window 1 ${ha} $Foo
+    if:
+      shell: ${Foo}
+    panes:
+      - shell_command:
+          - echo "this shouldn't shows up"
+      - echo neither should this $Foo
+  - window_name: window 2
+    panes:
+      # should not shows up
+      - if:
+          python: 1+1==3
+        shell_command:
+          - echo the above is a false statement
+      # no if conditions
+      - shell_command:
+          - echo no condition
+          - python -m http.server
+      # display by default, but can be disabled by running `show_htop=false tmuxp load .....`
+      - if: ${show_htop}
+        shell_command:
+          - echo the above is a true statement (by default), but can be disabled on-demand
+          - htop

From e95fda969d2bcd4f5d789cb28e9aaf2c5315bdbc Mon Sep 17 00:00:00 2001
From: Tin Lai <tin@tinyiu.com>
Date: Mon, 22 Jul 2024 21:23:01 +1000
Subject: [PATCH 04/10] support shell expression and python statements

Signed-off-by: Tin Lai <tin@tinyiu.com>
---
 examples/if-conditions.yaml   | 17 +++++++++--------
 src/tmuxp/workspace/loader.py | 30 ++++++++++++++++++------------
 2 files changed, 27 insertions(+), 20 deletions(-)

diff --git a/examples/if-conditions.yaml b/examples/if-conditions.yaml
index 425aec4325..077f6ce385 100644
--- a/examples/if-conditions.yaml
+++ b/examples/if-conditions.yaml
@@ -5,25 +5,26 @@ environment:
 windows:
   # the following would not shows up as it evaluates to false
   - window_name: window 1 ${ha} $Foo
-    if:
-      shell: ${Foo}
+    if: ${Foo}
     panes:
       - shell_command:
           - echo "this shouldn't shows up"
       - echo neither should this $Foo
   - window_name: window 2
     panes:
-      # should not shows up
+      # should not shows up; using shell expression
       - if:
-          python: 1+1==3
+          shell: '[ 5 -lt 4 ]'
         shell_command:
           - echo the above is a false statement
-      # no if conditions
-      - shell_command:
-          - echo no condition
+      # python conditions
+      - if:
+          python: import os; os.path.isdir('${PWD}')
+        shell_command:
+          - echo "checking for PWD (${PWD}) is a directory in python"
           - python -m http.server
       # display by default, but can be disabled by running `show_htop=false tmuxp load .....`
       - if: ${show_htop}
         shell_command:
-          - echo the above is a true statement (by default), but can be disabled on-demand
+          - echo "the above is a true statement (by default), but can be disabled on-demand"
           - htop
diff --git a/src/tmuxp/workspace/loader.py b/src/tmuxp/workspace/loader.py
index dfd5496625..67bd6060fa 100644
--- a/src/tmuxp/workspace/loader.py
+++ b/src/tmuxp/workspace/loader.py
@@ -3,6 +3,7 @@
 import logging
 import os
 import pathlib
+import subprocess
 import typing as t
 
 logger = logging.getLogger(__name__)
@@ -16,9 +17,10 @@ def optional_windows_and_pane(
     The function evaluates the 'if' condition specified in `workspace_dict` to determine inclusion:
     - If 'if' key is not present, it defaults to True.
     - If 'if' is a string or boolean, it's treated as a shell variable.
-    - 'if' can be a dictionary containing 'shell' or 'python' keys with valid expressions.
-    - 'shell' expressions are expanded and checked against true values ('y', 'yes', '1', 'on', 'true', 't').
-    - 'python' expressions are evaluated using `eval()`
+    - 'if' can be a dictionary containing 'shell', 'shell_var' or 'python' keys with valid expressions.
+    - 'shell_var' expressions are expanded and checked against true values ('y', 'yes', '1', 'on', 'true', 't').
+    - 'shell' expressions are evaluated using subprocess
+    - 'python' expressions are evaluated using `exec()`
 
     Parameters
     ----------
@@ -35,18 +37,22 @@ def optional_windows_and_pane(
     if_cond = workspace_dict["if"]
     if isinstance(if_cond, (str, bool)):
         # treat this as shell variable
-        if_cond = {"shell": if_cond}
-    if not isinstance(if_cond, dict) or not ("shell" in if_cond or "python" in if_cond):
+        if_cond = {"shell_var": if_cond}
+    if not isinstance(if_cond, dict) or not any(predicate in if_cond for predicate in ("python", "shell", "shell_var")):
         raise ValueError(f"if conditions does not contains valid expression: {if_cond}")
+    if "shell_var" in if_cond:
+        if expandshell(str(if_cond["shell_var"])).lower() not in ("y", "yes", "1", "on", "true", "t"):
+            return False
     if "shell" in if_cond:
-        if isinstance(if_cond["shell"], str):
-            if expandshell(if_cond["shell"]).lower() not in ("y", "yes", "1", "on", "true", "t"):
-                return False
-        elif isinstance(if_cond["shell"], bool):
-            if not if_cond["shell"]:
-                return False
+        if subprocess.run(if_cond["shell"], shell=True).returncode != 0:
+            return False
     if "python" in if_cond:
-        if if_cond["python"] and not eval(if_cond["python"]):  # dangerous
+        # assign the result of the last statement from the python snippet
+        py_statements = if_cond["python"].split(";")
+        py_statements[-1] = f"ret={py_statements[-1]}"
+        locals = {}
+        exec(";".join(py_statements), {}, locals)
+        if not locals['ret']:
             return False
     return True
 

From 5c3807923da3f4045cf55556a6e43357176d5054 Mon Sep 17 00:00:00 2001
From: Tin Lai <tin@tinyiu.com>
Date: Mon, 22 Jul 2024 22:01:40 +1000
Subject: [PATCH 05/10] fix grammars

---
 docs/configuration/examples.md |  4 ++--
 examples/if-conditions.json    | 13 +++++++------
 examples/if-conditions.yaml    |  4 ++--
 3 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/docs/configuration/examples.md b/docs/configuration/examples.md
index 17ab54f56e..8fd8091a87 100644
--- a/docs/configuration/examples.md
+++ b/docs/configuration/examples.md
@@ -289,7 +289,7 @@ newer and tmux 3.0 or newer.
 
 ## `if` conditions
 
-tmuxp enables one to optionally open windows / panes based on coditions. The `if` conditions can appears in the configuration for window or pane.
+tmuxp enables one to optionally open windows / panes based on conditions. The `if` conditions can appears in the configuration for window or pane.
 
 ````{tab} YAML
 
@@ -320,7 +320,7 @@ should produce **only** a window with upper and lower split panes (others should
 $ show_htop=false tmuxp load examples/if-conditions.yaml
 ```
 
-will insteads suppress the `htop` command pane and resulting in a different behaviour.
+will instead suppress the `htop` command pane and resulting in a different behaviour.
 
 ## Focusing
 
diff --git a/examples/if-conditions.json b/examples/if-conditions.json
index 1765326243..4c34e8eae5 100644
--- a/examples/if-conditions.json
+++ b/examples/if-conditions.json
@@ -7,9 +7,7 @@
   "windows": [
     {
       "window_name": "window 1 ${ha} $Foo",
-      "if": {
-        "shell": "${Foo}"
-      },
+      "if": "${Foo}",
       "panes": [
         {
           "shell_command": [
@@ -24,22 +22,25 @@
       "panes": [
         {
           "if": {
-            "python": "1+1==3"
+            "shell": "[ 5 -lt 4 ]"
           },
           "shell_command": [
             "echo the above is a false statement"
           ]
         },
         {
+          "if": {
+            "python": "import os; os.path.isdir('${PWD}')"
+          },
           "shell_command": [
-            "echo no condition",
+            "echo \"checking for PWD (${PWD}) is a directory in python\"",
             "python -m http.server"
           ]
         },
         {
           "if": "${show_htop}",
           "shell_command": [
-            "echo the above is a true statement (by default), but can be disabled on-demand",
+            "echo \"the above is a true statement (by default), but can be disabled on-demand\"",
             "htop"
           ]
         }
diff --git a/examples/if-conditions.yaml b/examples/if-conditions.yaml
index 077f6ce385..6d07b87441 100644
--- a/examples/if-conditions.yaml
+++ b/examples/if-conditions.yaml
@@ -12,12 +12,12 @@ windows:
       - echo neither should this $Foo
   - window_name: window 2
     panes:
-      # should not shows up; using shell expression
+      # shell expression condition; should not show up
       - if:
           shell: '[ 5 -lt 4 ]'
         shell_command:
           - echo the above is a false statement
-      # python conditions
+      # python condition
       - if:
           python: import os; os.path.isdir('${PWD}')
         shell_command:

From abd97718bdeeff1107a7ac778ccb52aa3698c8bf Mon Sep 17 00:00:00 2001
From: Tin Lai <tin@tinyiu.com>
Date: Mon, 22 Jul 2024 22:13:06 +1000
Subject: [PATCH 06/10] add tests for if conditions

Signed-off-by: Tin Lai <tin@tinyiu.com>
---
 examples/if-conditions-test.yaml | 48 ++++++++++++++++++++++++++++++++
 examples/if-conditions.yaml      |  2 +-
 tests/workspace/test_builder.py  | 28 +++++++++++++++++++
 3 files changed, 77 insertions(+), 1 deletion(-)
 create mode 100644 examples/if-conditions-test.yaml

diff --git a/examples/if-conditions-test.yaml b/examples/if-conditions-test.yaml
new file mode 100644
index 0000000000..95b84ac8c6
--- /dev/null
+++ b/examples/if-conditions-test.yaml
@@ -0,0 +1,48 @@
+session_name: if conditions test conditions
+environment:
+  foo: 'false'
+  bar: '1'
+  F: '0'
+windows:
+  - window_name: window all false
+    panes:
+      - if: ${foo}
+        shell_command:
+          - echo pane 1
+      - if:
+          shell: '[ 1 -gt 2 ]'
+        shell_command:
+          - echo pane 2
+      - if:
+          shell_var: ${F}
+  - window_name: window 2 of 3 true
+    panes:
+      - if:
+          shell: '[ "foo" = "bar" ]'
+        shell_command:
+          - echo pane 3
+      - if:
+          shell: '[ "hello" != "byte" ]'
+        shell_command:
+          - echo pane 4
+      - if:
+          python: '2**4 == 16'
+        shell_command:
+          - echo pane 5
+  - window_name: window 2 of 4 true
+    panes:
+      - if:
+          shell_var: 'FALSE'
+        shell_command:
+          - echo pane 6
+      - if:
+          shell_var: ${bar}
+        shell_command:
+          - echo pane 7
+      - if:
+          python: import os; not os.path.isdir('/a/very/random/path')
+        shell_command:
+          - echo pane 8
+      - if: ${non_existing_var}
+        shell_command:
+          - echo pane 9
diff --git a/examples/if-conditions.yaml b/examples/if-conditions.yaml
index 6d07b87441..b8871d93be 100644
--- a/examples/if-conditions.yaml
+++ b/examples/if-conditions.yaml
@@ -19,7 +19,7 @@ windows:
           - echo the above is a false statement
       # python condition
       - if:
-          python: import os; os.path.isdir('${PWD}')
+          python: import os; os.path.isdir(os.path.expandvars('${PWD}'))
         shell_command:
           - echo "checking for PWD (${PWD}) is a directory in python"
           - python -m http.server
diff --git a/tests/workspace/test_builder.py b/tests/workspace/test_builder.py
index 801b462d5a..692d01ed9d 100644
--- a/tests/workspace/test_builder.py
+++ b/tests/workspace/test_builder.py
@@ -563,6 +563,34 @@ def test_blank_pane_spawn(
     assert len(window4.panes) == 2
 
 
+def test_if_conditions(
+    session: Session,
+) -> None:
+    """
+    Test various ways of spawning panes with conditions from a tmuxp configuration.
+    """
+    yaml_workspace_file = EXAMPLE_PATH / "if-conditions-test.yaml"
+    test_config = ConfigReader._from_file(yaml_workspace_file)
+
+    test_config = loader.expand(test_config)
+    builder = WorkspaceBuilder(session_config=test_config, server=session.server)
+    builder.build(session=session)
+
+    assert session == builder.session
+
+    with pytest.raises(ObjectDoesNotExist):
+        window1 = session.windows.get(window_name="window all false")
+        assert window1 is None
+
+    window2 = session.windows.get(window_name="window 2 of 3 true")
+    assert window2 is not None
+    assert len(window2.panes) == 2
+
+    window3 = session.windows.get(window_name="window 2 of 4 true")
+    assert window3 is not None
+    assert len(window3.panes) == 2
+
+
 def test_start_directory(session: Session, tmp_path: pathlib.Path) -> None:
     """Test workspace builder setting start_directory relative to current directory."""
     test_dir = tmp_path / "foo bar"

From 5b2797417378439ff8467cd29943050ebaca41ee Mon Sep 17 00:00:00 2001
From: Tin Lai <tin@tinyiu.com>
Date: Mon, 22 Jul 2024 22:18:16 +1000
Subject: [PATCH 07/10] linting

Signed-off-by: Tin Lai <tin@tinyiu.com>
---
 src/tmuxp/workspace/loader.py   | 24 +++++++++++++++++-------
 tests/workspace/test_builder.py |  4 +---
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/src/tmuxp/workspace/loader.py b/src/tmuxp/workspace/loader.py
index 67bd6060fa..b4512bc173 100644
--- a/src/tmuxp/workspace/loader.py
+++ b/src/tmuxp/workspace/loader.py
@@ -38,13 +38,23 @@ def optional_windows_and_pane(
     if isinstance(if_cond, (str, bool)):
         # treat this as shell variable
         if_cond = {"shell_var": if_cond}
-    if not isinstance(if_cond, dict) or not any(predicate in if_cond for predicate in ("python", "shell", "shell_var")):
-        raise ValueError(f"if conditions does not contains valid expression: {if_cond}")
+    if not isinstance(if_cond, dict) or not any(
+        predicate in if_cond for predicate in ("python", "shell", "shell_var")
+    ):
+        msg = f"if conditions does not contains valid expression: {if_cond}"
+        raise ValueError(msg)
     if "shell_var" in if_cond:
-        if expandshell(str(if_cond["shell_var"])).lower() not in ("y", "yes", "1", "on", "true", "t"):
+        if expandshell(str(if_cond["shell_var"])).lower() not in {
+            "y",
+            "yes",
+            "1",
+            "on",
+            "true",
+            "t",
+        }:
             return False
     if "shell" in if_cond:
-        if subprocess.run(if_cond["shell"], shell=True).returncode != 0:
+        if subprocess.run(if_cond["shell"], shell=True, check=False).returncode != 0:
             return False
     if "python" in if_cond:
         # assign the result of the last statement from the python snippet
@@ -52,7 +62,7 @@ def optional_windows_and_pane(
         py_statements[-1] = f"ret={py_statements[-1]}"
         locals = {}
         exec(";".join(py_statements), {}, locals)
-        if not locals['ret']:
+        if not locals["ret"]:
             return False
     return True
 
@@ -224,7 +234,7 @@ def expand(
     if "windows" in workspace_dict:
         window_dicts = workspace_dict["windows"]
         window_dicts = filter(optional_windows_and_pane, window_dicts)
-        window_dicts = map(lambda x: expand(x, parent=workspace_dict), window_dicts)
+        window_dicts = (expand(x, parent=workspace_dict) for x in window_dicts)
         # remove windows that has no panels (e.g. due to if conditions)
         window_dicts = filter(lambda x: len(x["panes"]), window_dicts)
         workspace_dict["windows"] = list(window_dicts)
@@ -235,7 +245,7 @@ def expand(
             pane_dicts[pane_idx] = {}
             pane_dicts[pane_idx].update(expand_cmd(pane_dict))
         pane_dicts = filter(optional_windows_and_pane, pane_dicts)
-        pane_dicts = map(lambda x: expand(x, parent=workspace_dict), pane_dicts)
+        pane_dicts = (expand(x, parent=workspace_dict) for x in pane_dicts)
         workspace_dict["panes"] = list(pane_dicts)
 
     return workspace_dict
diff --git a/tests/workspace/test_builder.py b/tests/workspace/test_builder.py
index 692d01ed9d..a36f7e7836 100644
--- a/tests/workspace/test_builder.py
+++ b/tests/workspace/test_builder.py
@@ -566,9 +566,7 @@ def test_blank_pane_spawn(
 def test_if_conditions(
     session: Session,
 ) -> None:
-    """
-    Test various ways of spawning panes with conditions from a tmuxp configuration.
-    """
+    """Test various ways of spawning panes with conditions from a tmuxp configuration."""
     yaml_workspace_file = EXAMPLE_PATH / "if-conditions-test.yaml"
     test_config = ConfigReader._from_file(yaml_workspace_file)
 

From 1ac1d8ec23bdeb0b665a502989c6f376ebdf34e4 Mon Sep 17 00:00:00 2001
From: Tin Lai <tin@tinyiu.com>
Date: Mon, 22 Jul 2024 22:21:31 +1000
Subject: [PATCH 08/10] fix grammar

Signed-off-by: Tin Lai <tin@tinyiu.com>
---
 examples/if-conditions.json | 2 +-
 examples/if-conditions.yaml | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/examples/if-conditions.json b/examples/if-conditions.json
index 4c34e8eae5..815bd192c3 100644
--- a/examples/if-conditions.json
+++ b/examples/if-conditions.json
@@ -11,7 +11,7 @@
       "panes": [
         {
           "shell_command": [
-            "echo \"this shouldn't shows up\""
+            "echo \"this shouldn't show up\""
           ]
         },
         "echo neither should this $Foo"
diff --git a/examples/if-conditions.yaml b/examples/if-conditions.yaml
index b8871d93be..b11e884d69 100644
--- a/examples/if-conditions.yaml
+++ b/examples/if-conditions.yaml
@@ -3,12 +3,12 @@ environment:
   Foo: 'false'
   show_htop: 'true'
 windows:
-  # the following would not shows up as it evaluates to false
+  # the following would not show up as it evaluates to false
   - window_name: window 1 ${ha} $Foo
     if: ${Foo}
     panes:
       - shell_command:
-          - echo "this shouldn't shows up"
+          - echo "this shouldn't show up"
       - echo neither should this $Foo
   - window_name: window 2
     panes:

From 5b1e30d0aaea8f8c74274b341008e829700ba69f Mon Sep 17 00:00:00 2001
From: Tin Lai <tin@tinyiu.com>
Date: Mon, 22 Jul 2024 22:30:12 +1000
Subject: [PATCH 09/10] more comprehensive example that uses pipe and grep

Signed-off-by: Tin Lai <tin@tinyiu.com>
---
 examples/if-conditions-test.yaml | 5 +++++
 src/tmuxp/workspace/loader.py    | 7 ++++++-
 tests/workspace/test_builder.py  | 2 +-
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/examples/if-conditions-test.yaml b/examples/if-conditions-test.yaml
index 95b84ac8c6..345f95a74a 100644
--- a/examples/if-conditions-test.yaml
+++ b/examples/if-conditions-test.yaml
@@ -3,6 +3,7 @@ environment:
   foo: 'false'
   bar: '1'
   F: '0'
+  MY_VAR: myfoobar
 windows:
   - window_name: window all false
     panes:
@@ -46,3 +47,7 @@ windows:
       - if: ${non_existing_var}
         shell_command:
           - echo pane 9
+      - if:
+          shell: echo ${MY_VAR} | grep -q foo
+        shell_command:
+          - echo pane 10
diff --git a/src/tmuxp/workspace/loader.py b/src/tmuxp/workspace/loader.py
index b4512bc173..02091a9367 100644
--- a/src/tmuxp/workspace/loader.py
+++ b/src/tmuxp/workspace/loader.py
@@ -54,7 +54,12 @@ def optional_windows_and_pane(
         }:
             return False
     if "shell" in if_cond:
-        if subprocess.run(if_cond["shell"], shell=True, check=False).returncode != 0:
+        if (
+            subprocess.run(
+                expandshell(if_cond["shell"]), shell=True, check=False
+            ).returncode
+            != 0
+        ):
             return False
     if "python" in if_cond:
         # assign the result of the last statement from the python snippet
diff --git a/tests/workspace/test_builder.py b/tests/workspace/test_builder.py
index a36f7e7836..cf5d6d05e2 100644
--- a/tests/workspace/test_builder.py
+++ b/tests/workspace/test_builder.py
@@ -586,7 +586,7 @@ def test_if_conditions(
 
     window3 = session.windows.get(window_name="window 2 of 4 true")
     assert window3 is not None
-    assert len(window3.panes) == 2
+    assert len(window3.panes) == 3
 
 
 def test_start_directory(session: Session, tmp_path: pathlib.Path) -> None:

From 3cfc5df3edb4a4cb767d1c122f01ccf3a35d568d Mon Sep 17 00:00:00 2001
From: Tin Lai <tin@tinyiu.com>
Date: Mon, 22 Jul 2024 22:36:12 +1000
Subject: [PATCH 10/10] ruff

Signed-off-by: Tin Lai <tin@tinyiu.com>
---
 src/tmuxp/workspace/loader.py | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/src/tmuxp/workspace/loader.py b/src/tmuxp/workspace/loader.py
index 02091a9367..b8d35b8b31 100644
--- a/src/tmuxp/workspace/loader.py
+++ b/src/tmuxp/workspace/loader.py
@@ -53,14 +53,15 @@ def optional_windows_and_pane(
             "t",
         }:
             return False
-    if "shell" in if_cond:
-        if (
-            subprocess.run(
-                expandshell(if_cond["shell"]), shell=True, check=False
-            ).returncode
-            != 0
-        ):
-            return False
+    if "shell" in if_cond and (
+        subprocess.run(
+            expandshell(if_cond["shell"]),
+            shell=True,
+            check=False,
+        ).returncode
+        != 0
+    ):
+        return False
     if "python" in if_cond:
         # assign the result of the last statement from the python snippet
         py_statements = if_cond["python"].split(";")