Install init dependencies into a project .venv

nitrostack/cli/install.py

@@ -27,8 +27,35 @@ def _optional_extra_names(pyproject_text: str) -> List[str]:
     return names
 
 
+def venv_dir(root: str) -> str:
+    return os.path.join(root, ".venv")
+
+
+def venv_python(root: str) -> str:
+    if os.name == "nt":
+        return os.path.join(venv_dir(root), "Scripts", "python.exe")
+    return os.path.join(venv_dir(root), "bin", "python")
+
+
+def ensure_project_venv(root: str) -> str:
+    """Create ``<root>/.venv`` if needed and return its Python executable."""
+    python = venv_python(root)
+    if os.path.isfile(python):
+        return python
+    dest = venv_dir(root)
+    print(f"Creating virtualenv: {dest}")
+    result = subprocess.run([sys.executable, "-m", "venv", dest])
+    if result.returncode != 0 or not os.path.isfile(python):
+        raise RuntimeError(
+            f"Failed to create {dest}.\n"
+            f"Create it manually with `{sys.executable} -m venv .venv`, then retry."
+        )
+    return python
+
+
 def _run_pip(args: List[str], cwd: str) -> None:
-    cmd = [sys.executable, "-m", "pip", "install", *args]
+    python = ensure_project_venv(cwd)
+    cmd = [python, "-m", "pip", "install", *args]
     print(f"Running: {' '.join(cmd)}")
     result = subprocess.run(cmd, cwd=cwd)
     if result.returncode != 0:
@@ -59,6 +86,7 @@ def install_dependencies(
         )
 
     print("NITROSTACK — Install" + (" (production)" if production else ""))
+    print(f"Target: {venv_dir(root)}")
 
     if os.path.isfile(pyproject):
         extras: List[str] = []

nitrostack/cli/main.py

@@ -1343,22 +1343,30 @@ def init_project(name: str = None, template: str = None, skip_install: bool = Fa
         except Exception:
             pass
 
-    # 9. Run npm install inside widgets directory
-    widgets_dir = os.path.join(name, "src", "widgets")
-    if os.path.exists(widgets_dir) and install_deps:
-        print("Installing widget dependencies...")
+    # 9. Install Python deps (requirements.txt / pyproject.toml), then widget npm if present.
+    if install_deps:
+        print("Installing dependencies...")
         try:
-            _run_npm(["--version"], capture_output=True, check=True, text=True)
-            _run_npm(["install"], cwd=widgets_dir, check=True)
-            print("\033[32m✓\033[0m Widget dependencies installed\n")
-        except FileNotFoundError as e:
-            print(f"Warning: {e}")
-            print("Please run 'npm install' inside 'src/widgets' manually.\n")
-        except subprocess.CalledProcessError as e:
-            detail = (getattr(e, "stderr", None) or getattr(e, "stdout", None) or str(e)).strip()
-            print(f"Warning: Failed to install widget dependencies: {detail}")
-            print("Please run 'npm install' inside 'src/widgets' manually.\n")
-    elif not install_deps:
+            install_dependencies(cwd=name)
+            print("\033[32m✓\033[0m Dependencies installed")
+        except Exception as e:
+            print(f"Warning: Failed to install dependencies: {e}")
+            print("Please run 'nitrostack-py install' from the project directory.\n")
+        widgets_dir = os.path.join(name, "src", "widgets")
+        if os.path.exists(widgets_dir):
+            print("Installing widget dependencies...")
+            try:
+                _run_npm(["--version"], capture_output=True, check=True, text=True)
+                _run_npm(["install"], cwd=widgets_dir, check=True)
+                print("\033[32m✓\033[0m Widget dependencies installed\n")
+            except FileNotFoundError as e:
+                print(f"Warning: {e}")
+                print("Please run 'npm install' inside 'src/widgets' manually.\n")
+            except subprocess.CalledProcessError as e:
+                detail = (getattr(e, "stderr", None) or getattr(e, "stdout", None) or str(e)).strip()
+                print(f"Warning: Failed to install widget dependencies: {detail}")
+                print("Please run 'npm install' inside 'src/widgets' manually.\n")
+    else:
         print("\033[32m✓\033[0m Skipped dependency install")
 
     run_skills_flow(os.path.abspath(name), force=force)
@@ -1727,7 +1735,7 @@ def main():
         default=None,
         help="Template to use: python-starter, python-pizzaz, python-oauth (default: interactive prompt)",
     )
-    init_parser.add_argument("--skip-install", action="store_true", help="Skip installing widget npm dependencies")
+    init_parser.add_argument("--skip-install", action="store_true", help="Skip installing Python (and widget npm) dependencies")
     init_parser.add_argument(
         "--force",
         action="store_true",

tests/test_cli.py

@@ -299,13 +299,17 @@ def test_init_port_and_widget_flags_override_defaults():
 
 
 def test_init_install_dependencies_prompt_no():
+    from unittest.mock import patch
+
     tmp = tempfile.mkdtemp(prefix="nitro-cli-install-")
     original_cwd = os.getcwd()
     original_stdin = sys.stdin
     try:
         os.chdir(tmp)
         sys.stdin = io.StringIO("desc\nauthor\nn\n")
-        init_project("no-npm", template="python-starter")
+        with patch("nitrostack.cli.main.install_dependencies") as pip_install:
+            init_project("no-npm", template="python-starter")
+            pip_install.assert_not_called()
         widgets = os.path.join(tmp, "no-npm", "src", "widgets", "node_modules")
         assert not os.path.isdir(widgets)
         print("Success! Install dependencies (Y/n) respects n.")
@@ -569,11 +573,20 @@ def test_init_project_overwrite_and_install_yes_calls_npm():
         assert not os.path.exists(os.path.join("taken", "old.txt"))
 
         sys.stdin = io.StringIO("d\na\nY\n")
-        with patch("nitrostack.cli.main._run_npm") as npm:
-            init_project("installed", template="python-starter")
-            npm.assert_not_called()
+        with patch("nitrostack.cli.main.install_dependencies") as pip_install:
+            with patch("nitrostack.cli.main._run_npm") as npm:
+                init_project("installed", template="python-starter")
+                pip_install.assert_called_once()
+                assert pip_install.call_args.kwargs["cwd"] == "installed"
+                npm.assert_not_called()
         assert os.path.isfile(os.path.join("installed", "widgets", "out", "calculator-result.html"))
-        print("Success! init_project overwrite and install-yes npm path work.")
+
+        sys.stdin = io.StringIO("d\na\n\n")
+        with patch("nitrostack.cli.main.install_dependencies") as pip_install:
+            init_project("installed-enter", template="python-starter")
+            pip_install.assert_called_once()
+            assert pip_install.call_args.kwargs["cwd"] == "installed-enter"
+        print("Success! init_project overwrite and install-yes pip path work.")
     finally:
         sys.stdin = original_stdin
         os.chdir(original_cwd)

tests/test_cli_install.py

@@ -12,7 +12,9 @@
 from nitrostack.cli.install import (
     _optional_extra_names,
     _run_pip,
+    ensure_project_venv,
     install_dependencies,
+    venv_python,
 )
 
 
@@ -68,7 +70,38 @@ def test_install_requirements_txt_and_dev_file(tmp_path):
 
 
 def test_run_pip_raises_on_nonzero_exit(tmp_path):
-    with patch("nitrostack.cli.install.subprocess.run") as run:
-        run.return_value.returncode = 3
-        with pytest.raises(RuntimeError, match="exit code 3"):
-            _run_pip(["-e", "."], cwd=str(tmp_path))
+    with patch("nitrostack.cli.install.ensure_project_venv", return_value=sys.executable):
+        with patch("nitrostack.cli.install.subprocess.run") as run:
+            run.return_value.returncode = 3
+            with pytest.raises(RuntimeError, match="exit code 3"):
+                _run_pip(["-e", "."], cwd=str(tmp_path))
+
+
+def test_ensure_project_venv_creates_and_reuses(tmp_path):
+    python = venv_python(str(tmp_path))
+
+    def fake_venv(cmd, **kwargs):
+        os.makedirs(os.path.dirname(python), exist_ok=True)
+        open(python, "w", encoding="utf-8").write("")
+        return type("R", (), {"returncode": 0})()
+
+    with patch("nitrostack.cli.install.subprocess.run", side_effect=fake_venv) as run:
+        first = ensure_project_venv(str(tmp_path))
+        second = ensure_project_venv(str(tmp_path))
+    assert first == python == second
+    run.assert_called_once()
+    assert run.call_args.args[0][:3] == [sys.executable, "-m", "venv"]
+
+
+def test_install_requirements_uses_venv_python(tmp_path):
+    (tmp_path / "requirements.txt").write_text("nitrostack\n", encoding="utf-8")
+    venv_py = venv_python(str(tmp_path))
+    with patch("nitrostack.cli.install.ensure_project_venv", return_value=venv_py) as ensure:
+        with patch("nitrostack.cli.install.subprocess.run") as run:
+            run.return_value.returncode = 0
+            install_dependencies(cwd=str(tmp_path), production=False)
+    ensure.assert_called()
+    cmd = run.call_args.args[0]
+    assert cmd[0] == venv_py
+    assert cmd[1:4] == ["-m", "pip", "install"]
+    assert cmd[4] == "-r"