Added FuncAlias

news/funcalias.rst

@@ -0,0 +1,24 @@
+**Added:**
+
+* Added FuncAlias to process callable aliases.
+* Added alias name printing in case of exception in alias.
+
+**Changed:**
+
+* <news item>
+
+**Deprecated:**
+
+* <news item>
+
+**Removed:**
+
+* <news item>
+
+**Fixed:**
+
+* Fixed showing alias description using superhelp e.g. ``which?``.
+
+**Security:**
+
+* <news item>

tests/test_aliases.py

@@ -9,7 +9,7 @@
 from xonsh.aliases import Aliases, ExecAlias
 
 
-def cd(args, stdin=None, **kwargs):
+def cd(args, stdin=None):
     return args
 
 
@@ -30,10 +30,11 @@ def test_imports(xession):
         "o": ["omg", "lala"],
         "ls": ["ls", "-  -"],
         "color_ls": ["ls", "--color=true"],
-        "cd": cd,
+        "cd": "FuncAlias",
         "indirect_cd": ["cd", ".."],
     }
     raw = ales._raw
+    raw["cd"] = type(ales["cd"]).__name__
     assert raw == expected
 
 

tests/test_integrations.py

@@ -1000,6 +1000,177 @@ def test_run_fail_not_on_path():
     assert out != "Hello world"
 
 
+ALIASES_THREADABLE_PRINT_CASES = [
+    (
+        """
+$RAISE_SUBPROC_ERROR = False
+$XONSH_SHOW_TRACEBACK = False
+aliases['f'] = lambda: 1/0
+echo f1f1f1 ; f ; echo f2f2f2
+""",
+        "^f1f1f1\nException in thread.*FuncAlias.*\nZeroDivisionError.*\nf2f2f2\n$",
+    ),
+    (
+        """
+$RAISE_SUBPROC_ERROR = True
+$XONSH_SHOW_TRACEBACK = False
+aliases['f'] = lambda: 1/0
+echo f1f1f1 ; f ; echo f2f2f2
+""",
+        "f1f1f1\nException in thread.*\nZeroDivisionError: .*\nsubprocess.CalledProcessError.*\n$",
+    ),
+    (
+        """
+$RAISE_SUBPROC_ERROR = True
+$XONSH_SHOW_TRACEBACK = True
+aliases['f'] = lambda: 1/0
+echo f1f1f1 ; f ; echo f2f2f2
+""",
+        "f1f1f1\nException in thread.*\nTraceback.*\nZeroDivisionError: .*\nsubprocess.CalledProcessError.*\n$",
+    ),
+    (
+        """
+$RAISE_SUBPROC_ERROR = False
+$XONSH_SHOW_TRACEBACK = True
+aliases['f'] = lambda: 1/0
+echo f1f1f1 ; f ; echo f2f2f2
+""",
+        "f1f1f1\nException in thread.*FuncAlias.*\nTraceback.*\nZeroDivisionError.*\nf2f2f2\n$",
+    ),
+    (
+        """
+$RAISE_SUBPROC_ERROR = False
+$XONSH_SHOW_TRACEBACK = False
+aliases['f'] = lambda: (None, "I failed", 2)
+echo f1f1f1 ; f ; echo f2f2f2
+""",
+        "^f1f1f1\nI failed\nf2f2f2\n$",
+    ),
+    (
+        """
+$RAISE_SUBPROC_ERROR = True
+$XONSH_SHOW_TRACEBACK = False
+aliases['f'] = lambda: (None, "I failed", 2)
+echo f1f1f1 ; f ; echo f2f2f2
+""",
+        "f1f1f1\nI failed\nsubprocess.CalledProcessError.*\n$",
+    ),
+    (
+        """
+$RAISE_SUBPROC_ERROR = True
+$XONSH_SHOW_TRACEBACK = True
+aliases['f'] = lambda: (None, "I failed", 2)
+echo f1f1f1 ; f ; echo f2f2f2
+""",
+        "f1f1f1\nI failed.*\nTraceback.*\nsubprocess.CalledProcessError.*\n$",
+    ),
+    (
+        """
+$RAISE_SUBPROC_ERROR = False
+$XONSH_SHOW_TRACEBACK = True
+aliases['f'] = lambda: (None, "I failed", 2)
+echo f1f1f1 ; f ; echo f2f2f2
+""",
+        "f1f1f1\nI failed\nf2f2f2\n$",
+    ),
+]
+
+ALIASES_UNTHREADABLE_PRINT_CASES = [
+    (
+        """
+$RAISE_SUBPROC_ERROR = False
+$XONSH_SHOW_TRACEBACK = False
+aliases['f'] = lambda: 1/0
+aliases['f'].__xonsh_threadable__ = False
+echo f1f1f1 ; f ; echo f2f2f2
+""",
+        "^f1f1f1\nException in.*FuncAlias.*\nZeroDivisionError.*\nf2f2f2\n$",
+    ),
+    (
+        """
+$RAISE_SUBPROC_ERROR = True
+$XONSH_SHOW_TRACEBACK = False
+aliases['f'] = lambda: 1/0
+aliases['f'].__xonsh_threadable__ = False
+echo f1f1f1 ; f ; echo f2f2f2
+""",
+        "f1f1f1\nException in.*\nZeroDivisionError: .*\nsubprocess.CalledProcessError.*\n$",
+    ),
+    (
+        """
+$RAISE_SUBPROC_ERROR = True
+$XONSH_SHOW_TRACEBACK = True
+aliases['f'] = lambda: 1/0
+aliases['f'].__xonsh_threadable__ = False
+echo f1f1f1 ; f ; echo f2f2f2
+""",
+        "f1f1f1\nException in.*\nTraceback.*\nZeroDivisionError: .*\nsubprocess.CalledProcessError.*\n$",
+    ),
+    (
+        """
+$RAISE_SUBPROC_ERROR = False
+$XONSH_SHOW_TRACEBACK = True
+aliases['f'] = lambda: 1/0
+aliases['f'].__xonsh_threadable__ = False
+echo f1f1f1 ; f ; echo f2f2f2
+""",
+        "f1f1f1\nException in.*FuncAlias.*\nTraceback.*\nZeroDivisionError.*\nf2f2f2\n$",
+    ),
+    (
+        """
+$RAISE_SUBPROC_ERROR = False
+$XONSH_SHOW_TRACEBACK = False
+aliases['f'] = lambda: (None, "I failed", 2)
+aliases['f'].__xonsh_threadable__ = False
+echo f1f1f1 ; f ; echo f2f2f2
+""",
+        "^f1f1f1\nI failed\nf2f2f2\n$",
+    ),
+    (
+        """
+$RAISE_SUBPROC_ERROR = True
+$XONSH_SHOW_TRACEBACK = False
+aliases['f'] = lambda: (None, "I failed", 2)
+aliases['f'].__xonsh_threadable__ = False
+echo f1f1f1 ; f ; echo f2f2f2
+""",
+        "f1f1f1\nI failed\nsubprocess.CalledProcessError.*\n$",
+    ),
+    (
+        """
+$RAISE_SUBPROC_ERROR = True
+$XONSH_SHOW_TRACEBACK = True
+aliases['f'] = lambda: (None, "I failed", 2)
+aliases['f'].__xonsh_threadable__ = False
+echo f1f1f1 ; f ; echo f2f2f2
+""",
+        "f1f1f1\nI failed.*\nTraceback.*\nsubprocess.CalledProcessError.*\n$",
+    ),
+    (
+        """
+$RAISE_SUBPROC_ERROR = False
+$XONSH_SHOW_TRACEBACK = True
+aliases['f'] = lambda: (None, "I failed", 2)
+aliases['f'].__xonsh_threadable__ = False
+echo f1f1f1 ; f ; echo f2f2f2
+""",
+        "f1f1f1\nI failed\nf2f2f2\n$",
+    ),
+]
+
+
+@skip_if_on_windows
+@pytest.mark.parametrize(
+    "case", ALIASES_THREADABLE_PRINT_CASES + ALIASES_UNTHREADABLE_PRINT_CASES
+)
+def test_aliases_print(case):
+    cmd, match = case
+    out, err, ret = run_xonsh(cmd=cmd, single_command=False)
+    assert re.match(
+        match, out, re.MULTILINE | re.DOTALL
+    ), f"\nFailed:\n```\n{cmd.strip()}\n```,\nresult: {out!r}\nexpected: {match!r}."
+
+
 @skip_if_on_windows
 @pytest.mark.parametrize("interactive", [True, False])
 def test_raise_subproc_error_with_show_traceback(monkeypatch, interactive):

tests/test_tools.py

@@ -2122,17 +2122,17 @@ def test_print_exception_error(xession, capsys):
         match,
         cap.err,
         re.MULTILINE | re.DOTALL,
-    ), f"Assert: {cap.err!r} not matched with {match!r}"
+    ), f"\nAssert: {cap.err!r},\nexpected: {match!r}"
 
     with xession.env.swap(XONSH_SHOW_TRACEBACK=True):
         try:
             raise subprocess.CalledProcessError(1, ["ls", "nofile"], output="nooutput")
         except subprocess.CalledProcessError:
             print_exception(msg="MSG")
     cap = capsys.readouterr()
-    match = ".*Traceback.*subprocess.CalledProcessError: Command .* returned non-zero exit status .*\nMSG\n"
+    match = ".*Traceback.*subprocess.CalledProcessError: Command .* returned non-zero exit status .*MSG\n"
     assert re.match(
         match,
         cap.err,
         re.MULTILINE | re.DOTALL,
-    ), f"Assert: {cap.err!r} not matched with {match!r}"
+    ), f"\nAssert: {cap.err!r},\nexpected {match!r}"

xonsh/aliases.py

@@ -54,6 +54,37 @@ def EXEC_ALIAS_RE():
     return re.compile(r"@\(|\$\(|!\(|\$\[|!\[|\&\&|\|\||\s+and\s+|\s+or\s+|[>|<]")
 
 
+class FuncAlias:
+    """Provides a callable alias for xonsh commands."""
+
+    attributes_show = ["__xonsh_threadable__", "__xonsh_capturable__"]
+    attributes_inherit = attributes_show + ["__doc__"]
+
+    def __init__(self, name, func):
+        self.__name__ = self.name = name
+        self.func = func
+        for attr in self.attributes_inherit:
+            if (val := getattr(func, attr, None)) is not None:
+                self.__setattr__(attr, val)
+
+    def __repr__(self):
+        r = {"name": self.name, "func": self.func.__name__}
+        r |= {
+            attr: val
+            for attr in self.attributes_show
+            if (val := getattr(self, attr, None)) is not None
+        }
+        return f"FuncAlias({repr(r)})"
+
+    def __call__(
+        self, args=None, stdin=None, stdout=None, stderr=None, spec=None, stack=None
+    ):
+        func_args = [args, stdin, stdout, stderr, spec, stack][
+            : len(inspect.signature(self.func).parameters)
+        ]
+        return self.func(*func_args)
+
+
 class Aliases(cabc.MutableMapping):
     """Represents a location to hold and look up aliases."""
 
@@ -182,6 +213,8 @@ def __setitem__(self, key, val):
             else:
                 # need to exec alias
                 self._raw[key] = ExecAlias(val, filename=f)
+        elif isinstance(val, types.FunctionType):
+            self._raw[key] = FuncAlias(key, val)
         else:
             self._raw[key] = val
 
@@ -225,7 +258,7 @@ def __repr__(self):
 
 
 class ExecAlias:
-    """Provides a callable alias for xonsh source code."""
+    """Provides an exec alias for xonsh source code."""
 
     def __init__(self, src, filename="<exec-alias>"):
         """