refactor: raise unsupported package manager

Author: kevinobruno

src/python/pants/backend/javascript/nodejs_project.py

@@ -80,11 +80,13 @@ def generate_lockfile_args(self) -> tuple[str, ...]:
     def immutable_install_args(self) -> tuple[str, ...]:
         if self.package_manager == "npm":
             return ("clean-install",)
+        if self.package_manager == "pnpm":
+            return ("install", "--frozen-lockfile")
         if self.package_manager == "yarn":
             if nodesemver.satisfies(self.package_manager_version, "1.x"):
                 return ("install", "--frozen-lockfile")
             return ("install", "--immutable")
-        return ("install", "--frozen-lockfile")
+        raise ValueError(f"Unsupported package manager: {self.package_manager}")
 
     @property
     def workspace_specifier_arg(self) -> str:

src/python/pants/backend/javascript/nodejs_project_test.py

@@ -95,6 +95,19 @@ def test_immutable_install_args_property(rule_runner: RuleRunner) -> None:
     }
 
 
+def test_immutable_install_args_property_with_unsupported_package_manager(rule_runner: RuleRunner) -> None:
+    rule_runner.write_files(
+        {
+            "src/js/foo/BUILD": "package_json()",
+            "src/js/foo/package.json": given_package("foo", "0.0.1", package_manager="[email protected]"),
+        }
+    )
+    projects = rule_runner.request(AllNodeJSProjects, [])
+    expected_error = "Unsupported package manager: bar"
+    with pytest.raises(ValueError, match=expected_error):
+        {project.immutable_install_args for project in projects}
+
+
 def test_root_package_json_is_supported(rule_runner: RuleRunner) -> None:
     rule_runner.write_files(
         {