Nushell activation scripts (#2170)

4 files changed, 81 insertions, 0 deletions

diff --git a/src/virtualenv/activation/__init__.py b/src/virtualenv/activation/__init__.py
index 962cdf7..e9296d8 100644
--- a/src/virtualenv/activation/__init__.py
+++ b/src/virtualenv/activation/__init__.py
@@ -4,6 +4,7 @@ from .bash import BashActivator
 from .batch import BatchActivator
 from .cshell import CShellActivator
 from .fish import FishActivator
+from .nushell import NushellActivator
 from .powershell import PowerShellActivator
 from .python import PythonActivator
 
@@ -14,4 +15,5 @@ __all__ = [
     "PythonActivator",
     "BatchActivator",
     "FishActivator",
+    "NushellActivator",
 ]
diff --git a/src/virtualenv/activation/nushell/__init__.py b/src/virtualenv/activation/nushell/__init__.py
new file mode 100644
index 0000000..994c1fb
--- /dev/null
+++ b/src/virtualenv/activation/nushell/__init__.py
@@ -0,0 +1,28 @@
+from __future__ import absolute_import, unicode_literals
+
+import os
+
+from virtualenv.util.path import Path
+from virtualenv.util.six import ensure_text
+
+from ..via_template import ViaTemplateActivator
+
+
+class NushellActivator(ViaTemplateActivator):
+    def templates(self):
+        yield Path("activate.nu")
+        yield Path("deactivate.nu")
+
+    def replacements(self, creator, dest_folder):
+        # Due to nushell scoping, it isn't easy to create a function that will
+        # deactivate the environment. For that reason a __DEACTIVATE_PATH__
+        # replacement pointing to the deactivate.nu file is created
+
+        return {
+            "__VIRTUAL_PROMPT__": "" if self.flag_prompt is None else self.flag_prompt,
+            "__VIRTUAL_ENV__": ensure_text(str(creator.dest)),
+            "__VIRTUAL_NAME__": creator.env_name,
+            "__BIN_NAME__": ensure_text(str(creator.bin_dir.relative_to(creator.dest))),
+            "__PATH_SEP__": ensure_text(os.pathsep),
+            "__DEACTIVATE_PATH__": ensure_text(str(Path(dest_folder) / "deactivate.nu")),
+        }
diff --git a/src/virtualenv/activation/nushell/activate.nu b/src/virtualenv/activation/nushell/activate.nu
new file mode 100644
index 0000000..f0a4da4
--- /dev/null
+++ b/src/virtualenv/activation/nushell/activate.nu
@@ -0,0 +1,40 @@
+# Setting all environment variables for the venv
+let virtual-env = "__VIRTUAL_ENV__"
+let bin = "__BIN_NAME__"
+let path-sep = "__PATH_SEP__"
+
+let old-path = ($nu.path | str collect ($path-sep))
+
+let venv-path = ([$virtual-env $bin] | path join)
+let new-path = ($nu.path | prepend $venv-path | str collect ($path-sep))
+
+# environment variables that will be batched loaded to the virtual env
+let new-env = ([
+    [name, value];
+    [PATH $new-path]
+    [_OLD_VIRTUAL_PATH $old-path]
+    [VIRTUAL_ENV $virtual-env]
+])
+
+load-env $new-env
+
+# Creating the new prompt for the session
+let virtual_prompt = (if ("__VIRTUAL_PROMPT__" != "") {
+    "__VIRTUAL_PROMPT__"
+} {
+    $virtual-env | path basename
+}
+)
+
+# If there is no default prompt, then only the env is printed in the prompt
+let new_prompt = (if ( config | select prompt | empty? ) {
+    ($"build-string '(char lparen)' '($virtual_prompt)' '(char rparen) ' ")
+} {
+    ($"build-string '(char lparen)' '($virtual_prompt)' '(char rparen) ' (config get prompt | str find-replace "build-string" "")")
+})
+let-env PROMPT_COMMAND = $new_prompt
+
+# We are using alias as the function definitions because only aliases can be
+# removed from the scope
+alias pydoc = python -m pydoc
+alias deactivate = source "__DEACTIVATE_PATH__"
diff --git a/src/virtualenv/activation/nushell/deactivate.nu b/src/virtualenv/activation/nushell/deactivate.nu
new file mode 100644
index 0000000..4052438
--- /dev/null
+++ b/src/virtualenv/activation/nushell/deactivate.nu
@@ -0,0 +1,11 @@
+# Setting the old path
+let path-name = (if ((sys).host.name == "Windows") { "Path" } { "PATH" })
+let-env $path-name = $nu.env._OLD_VIRTUAL_PATH
+
+# Unleting the environment variables that were created when activating the env
+unlet-env VIRTUAL_ENV
+unlet-env _OLD_VIRTUAL_PATH
+unlet-env PROMPT_COMMAND
+
+unalias pydoc
+unalias deactivate