Revert "Revert #5423" (#5475)

Reverts xonsh/xonsh#5468

Closes #5466

Related #5423

---------

Co-authored-by: a <1@1.1>

news/fix_redir.rst

@@ -0,0 +1,23 @@
+**Added:**
+
+* <news item>
+
+**Changed:**
+
+* <news item>
+
+**Deprecated:**
+
+* <news item>
+
+**Removed:**
+
+* <news item>
+
+**Fixed:**
+
+* Fixed redirect with python substitution e.g. ``echo 1 > @('/tmp/file')`` is working now.
+
+**Security:**
+
+* <news item>

tests/procs/test_specs.py

@@ -353,6 +353,14 @@ def test_on_command_not_found_doesnt_fire_in_non_interactive_mode(xession):
     assert not fired
 
 
+def test_redirect_to_substitution(xession):
+    s = SubprocSpec.build(
+        # `echo hello > @('file')`
+        ["echo", "hello", (">", ["file"])]
+    )
+    assert s.stdout.name == "file"
+
+
 def test_partial_args_from_classmethod(xession):
     class Class:
         @classmethod

tests/test_integrations.py

@@ -156,6 +156,34 @@ f e>o
         "The Truth is Out There\n",
         0,
     ),
+    # test redirecting to a python substitution
+    (
+        """
+def _f():
+    print('Wow Mom!')
+aliases['f'] = _f
+f > @('tttt')
+with open('tttt') as tttt:
+    s = tttt.read().strip()
+print('REDIRECTED OUTPUT: ' + s)
+""",
+        "REDIRECTED OUTPUT: Wow Mom!\n",
+        0,
+    ),
+    # test redirecting to a python substitution with p-string
+    (
+        """
+def _f():
+    print('Wow Mom!')
+aliases['f'] = _f
+f > @(p'tttt')
+with open('tttt') as tttt:
+    s = tttt.read().strip()
+print('REDIRECTED OUTPUT: ' + s)
+""",
+        "REDIRECTED OUTPUT: Wow Mom!\n",
+        0,
+    ),
     # test system exit in function alias
     (
         """

tests/test_pipelines.py

@@ -74,7 +74,6 @@ def patched_events(monkeypatch, xonsh_events, xonsh_session):
         ("!(echo hi | grep x)", "", "", ""),
     ),
 )
-@pytest.mark.flaky(reruns=3, reruns_delay=2)
 def test_command_pipeline_capture(cmdline, stdout, stderr, raw_stdout, xonsh_execer):
     pipeline: CommandPipeline = xonsh_execer.eval(cmdline)
     assert pipeline.out == stdout

xonsh/procs/specs.py

@@ -223,6 +223,9 @@ def _parse_redirects(r, loc=None):
 
 def _redirect_streams(r, loc=None):
     """Returns stdin, stdout, stderr tuple of redirections."""
+    if isinstance(loc, list):
+        raise Exception(f"Unsupported redirect: {r!r} {loc!r}")
+
     stdin = stdout = stderr = None
     no_ampersand = r.replace("&", "")
     # special case of redirecting stderr to stdout
@@ -671,7 +674,21 @@ class SubprocSpec:
         """Weave a list of arguments into a command."""
         resolved_cmd = []
         for c in self.cmd:
-            resolved_cmd += c if isinstance(c, list) else [c]
+            if (
+                isinstance(c, tuple)
+                and len(c) == 2
+                and isinstance(c[1], list)
+                and len(c[1]) == 1
+            ):
+                # Redirect case e.g. `> file`
+                resolved_cmd.append(
+                    (
+                        c[0],
+                        c[1][0],
+                    )
+                )
+            else:
+                resolved_cmd += c if isinstance(c, list) else [c]
         self.cmd = resolved_cmd
 
     def resolve_redirects(self):