Add support for Xonsh virtual environment activation script (activate.xsh)

crates/uv-virtualenv/src/activator/activate.xsh

@@ -0,0 +1,102 @@
+# Copyright (c) 2020-202x The virtualenv developers
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+# This file must be used with "source bin/activate.xsh" *from xonsh*.
+# You cannot run it directly.
+
+
+class _VirtualEnvActivator:
+    """xonsh activation for virtualenv."""
+
+    # Stashed in _OLD_VIRTUAL_{name} when the variable was not set before
+    # activation. deactivate treats this as "unset" rather than "restore to
+    # this string".
+    _UNSET_SENTINEL = "__virtualenv_was_not_set__"
+
+    def __init__(self):
+        from os.path import dirname, realpath
+
+        self.env = __xonsh__.env
+        self.embedded_virtual_env = dirname(dirname(realpath(__file__)))
+        self.embedded_virtual_prompt = {{ VIRTUAL_PROMPT }}
+        self.embedded_bin_name = {{ BIN_NAME }}
+        self.managed_vars = ("PATH", "PYTHONHOME")
+
+    def _backup_name(self, name):
+        return f"_OLD_VIRTUAL_{name}"
+
+    def _save(self, name):
+        backup = self._backup_name(name)
+        self.env[backup] = self.env[name] if name in self.env else self._UNSET_SENTINEL
+
+    def _override(self, name, value):
+        self._save(name)
+        self.env[name] = value
+
+    def _drop(self, name):
+        self._save(name)
+        self.env.pop(name, None)
+
+    def register_pydoc(self):
+        aliases["pydoc"] = ["python", "-m", "pydoc"]
+
+    def unregister_pydoc(self):
+        aliases.pop("pydoc", None)
+
+    def activate(self):
+        from os.path import basename, join
+
+        aliases["deactivate"] = self.deactivate
+        self.deactivate(["nondestructive"]) # wipe any stale state from a prior activation
+
+        $VIRTUAL_ENV = self.embedded_virtual_env
+        $VIRTUAL_ENV_PROMPT = self.embedded_virtual_prompt or basename($VIRTUAL_ENV)
+
+        self._override("PATH", [join($VIRTUAL_ENV, self.embedded_bin_name), *$PATH])
+        self._drop("PYTHONHOME")
+        self.register_pydoc()
+
+    def deactivate(self, args=None):
+        for name in self.managed_vars:
+            backup = self._backup_name(name)
+            if backup not in self.env:
+                continue
+            previous = self.env[backup]
+            del self.env[backup]
+            if previous == self._UNSET_SENTINEL:
+                self.env.pop(name, None)
+            else:
+                self.env[name] = previous
+        for name in ("VIRTUAL_ENV", "VIRTUAL_ENV_PROMPT"):
+            self.env.pop(name, None)
+        self.unregister_pydoc()
+        if args is None or "nondestructive" not in args:
+            del aliases["deactivate"]
+            try:
+                del __xonsh__.xontrib.virtualenv
+            except AttributeError:
+                pass
+
+
+if not hasattr(__xonsh__, "xontrib"):
+    __xonsh__.xontrib = __xonsh__.imp.types.SimpleNamespace()
+__xonsh__.xontrib.virtualenv = _VirtualEnvActivator()
+__xonsh__.xontrib.virtualenv.activate()

crates/uv-virtualenv/src/virtualenv.rs

@@ -15,7 +15,7 @@ use owo_colors::OwoColorize;
 use tracing::{debug, trace};
 
 use crate::{Error, Prompt};
-use uv_fs::{CWD, Simplified, cachedir};
+use uv_fs::{CWD, PythonExt, Simplified, cachedir};
 use uv_platform_tags::Os;
 use uv_preview::PreviewFeature;
 use uv_pypi_types::Scheme;
@@ -33,6 +33,7 @@ const ACTIVATE_TEMPLATES: &[(&str, &str)] = &[
     ("activate.csh", include_str!("activator/activate.csh")),
     ("activate.fish", include_str!("activator/activate.fish")),
     ("activate.nu", include_str!("activator/activate.nu")),
+    ("activate.xsh", include_str!("activator/activate.xsh")),
     ("activate.ps1", include_str!("activator/activate.ps1")),
     ("activate.bat", include_str!("activator/activate.bat")),
     ("deactivate.bat", include_str!("activator/deactivate.bat")),
@@ -508,13 +509,24 @@ pub(crate) fn create(
             _ => escape_posix_for_single_quotes(location_string),
         };
 
+        let virtual_prompt = prompt.as_deref().unwrap_or_default();
+        let virtual_prompt = match *name {
+            "activate.xsh" => Cow::Owned(format!(
+                r#"b"{}".decode("utf-8")"#,
+                virtual_prompt.as_bytes().escape_ascii(),
+            )),
+            _ => Cow::Borrowed(virtual_prompt),
+        };
+
+        let bin_name = match *name {
+            "activate.xsh" => Cow::Owned(bin_name.escape_for_python()),
+            _ => Cow::Borrowed(bin_name),
+        };
+
         let activator = template
             .replace("{{ VIRTUAL_ENV_DIR }}", &virtual_env_dir)
-            .replace("{{ BIN_NAME }}", bin_name)
-            .replace(
-                "{{ VIRTUAL_PROMPT }}",
-                prompt.as_deref().unwrap_or_default(),
-            )
+            .replace("{{ BIN_NAME }}", &bin_name)
+            .replace("{{ VIRTUAL_PROMPT }}", &virtual_prompt)
             .replace("{{ PATH_SEP }}", path_sep)
             .replace("{{ RELATIVE_SITE_PACKAGES }}", &relative_site_packages);
         fs_err::write(scripts.join(name), activator)?;

crates/uv/tests/python/venv.rs

@@ -1687,6 +1687,7 @@ fn verify_pyvenv_cfg() {
 #[test]
 fn verify_pyvenv_cfg_relocatable() {
     let context = uv_test::test_context!("3.12");
+    let prompt = "résumé \"quoted\"\\path\n";
 
     // Create a virtual environment at `.venv`.
     context
@@ -1695,6 +1696,8 @@ fn verify_pyvenv_cfg_relocatable() {
         .arg("--clear")
         .arg("--python")
         .arg("3.12")
+        .arg("--prompt")
+        .arg(prompt)
         .arg("--relocatable")
         .assert()
         .success();
@@ -1750,6 +1753,15 @@ fn verify_pyvenv_cfg_relocatable() {
     // be generated when --relocatable is used.
     let activate_csh = scripts.child("activate.csh");
     activate_csh.assert(predicates::path::missing());
+
+    let activate_xsh = scripts.child("activate.xsh");
+    activate_xsh.assert(predicates::path::is_file());
+    activate_xsh.assert(predicates::str::contains(
+        r"dirname(dirname(realpath(__file__)))",
+    ));
+    activate_xsh.assert(predicates::str::contains(
+        r#"self.embedded_virtual_prompt = b"r\xc3\xa9sum\xc3\xa9 \"quoted\"\\path\n".decode("utf-8")"#,
+    ));
 }
 
 /// With `UV_VENV_RELOCATABLE=1`, the virtual environment is relocatable.