[FIX]: Attempt creation of symlink on Windows and handle exceptions. (#…

…958)

Co-authored-by: Bradley Dice <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

changelog.txt

@@ -14,6 +14,7 @@ Changed
 +++++++
 
  - linked views now can contain spaces and other characters except directory separators (#926).
+ - linked views now can be created on Windows, if 'Developer mode' is enabled (#430).
 
 [2.1.0] -- 2023-07-12
 ---------------------

contributors.yaml

@@ -138,4 +138,8 @@ contributors:
     family-names: Kadar
     given-names: Alain
     affiliation: "University of Michigan"
+  -
+    family-names: Stoimenov
+    given-names: Boyko
+    affiliation: "JTEKT Corp."
 ...

signac/linked_view.py

@@ -7,6 +7,7 @@
 import logging
 import os
 import sys
+import textwrap
 from itertools import chain
 
 from ._utility import _mkdir_p
@@ -38,21 +39,15 @@ def create_linked_view(project, prefix=None, job_ids=None, path=None):
     Raises
     ------
     OSError
-        Linked views cannot be created on Windows because
-        symbolic links are not supported by the platform.
+        If symbolic links are not enabled on Windows,
+        linked views cannot be created.
+
     RuntimeError
         When state points contain ``os.sep``.
 
     """
     from .import_export import _check_directory_structure_validity, _make_path_function
 
-    # Windows does not support the creation of symbolic links.
-    if sys.platform == "win32":
-        raise OSError(
-            "signac cannot create linked views on Windows, because "
-            "symbolic links are not supported by the platform."
-        )
-
     if prefix is None:
         prefix = "view"
 
@@ -85,8 +80,34 @@ def create_linked_view(project, prefix=None, job_ids=None, path=None):
         for job in project.find_jobs():
             links["./job"] = job.path
         assert len(links) < 2
-    _check_directory_structure_validity(links.keys())
-    _update_view(prefix, links)
+
+    # Updating the view will fail on Windows, if symlinks are not enabled.
+    # Before re-raising the exception, print a helpful message for the expected error.
+    try:
+        _check_directory_structure_validity(links.keys())
+        _update_view(prefix, links)
+    except OSError as err:
+        if sys.platform == "win32" and err.winerror == 1314:
+            print(
+                textwrap.dedent(
+                    f"""\
+                -------------------------------------------------------------------
+                Error:
+                {err.strerror}
+
+                You may not have permission to create Windows symlinks.
+                To enable the creation of symlinks on Windows you need
+                to enable 'Developer mode' (requires administrative rights).
+                To enable 'Developer mode':
+                  1. Go to 'Settings'.
+                  2. In the search bar type 'Use developer features'.
+                  3. Enable the item 'Developer mode'.
+                The details for Home edition and between Windows versions may vary.
+                -------------------------------------------------------------------
+                """
+                )
+            )
+        raise err.with_traceback(sys.exc_info()[2])
 
     return links
 

tests/test_project.py

@@ -1,6 +1,7 @@
 # Copyright (c) 2017 The Regents of the University of Michigan
 # All rights reserved.
 # This software is licensed under the BSD 3-Clause License.
+import functools
 import gzip
 import io
 import json
@@ -61,10 +62,31 @@
 except ImportError:
     NUMPY = False
 
-# Skip linked view tests on Windows
 WINDOWS = sys.platform == "win32"
 
 
+@functools.lru_cache
+def _check_symlinks_supported():
+    """Check if symlinks are supported on the current platform."""
+    try:
+        with TemporaryDirectory() as tmp_dir:
+            os.symlink(
+                os.path.realpath(__file__), os.path.join(tmp_dir, "test_symlink")
+            )
+        return True
+    except (NotImplementedError, OSError):
+        return False
+
+
+def skip_windows_without_symlinks(test_func):
+    """Skip test if platform is Windows and symlinks are not supported."""
+
+    return pytest.mark.skipif(
+        WINDOWS and not _check_symlinks_supported(),
+        reason="Symbolic links are unsupported on Windows unless in Developer Mode.",
+    )(test_func)
+
+
 class TestProjectBase(TestJobBase):
     pass
 
@@ -188,7 +210,7 @@ def test_no_workspace_warn_on_find(self, caplog):
             # constructor: https://bugs.python.org/issue33234
             assert len(caplog.records) in (2, 3)
 
-    @pytest.mark.skipif(WINDOWS, reason="Symbolic links are unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_workspace_broken_link_error_on_find(self):
         with TemporaryDirectory() as tmp_dir:
             project = self.project_class.init_project(path=tmp_dir)
@@ -1534,7 +1556,7 @@ def test_Schema_repr_methods(self, project_generator, num_jobs):
 
 
 class TestLinkedViewProject(TestProjectBase):
-    @pytest.mark.skipif(WINDOWS, reason="Linked views unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_create_linked_view(self):
         def clean(filter=None):
             """Helper function for wiping out views"""
@@ -1620,7 +1642,7 @@ def clean(filter=None):
         src = set(map(lambda j: os.path.realpath(j.path), self.project.find_jobs()))
         assert src == dst
 
-    @pytest.mark.skipif(WINDOWS, reason="Linked views unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_create_linked_view_homogeneous_schema_tree(self):
         view_prefix = os.path.join(self._tmp_pr, "view")
         a_vals = range(10)
@@ -1650,7 +1672,7 @@ def test_create_linked_view_homogeneous_schema_tree(self):
                         )
                     )
 
-    @pytest.mark.skipif(WINDOWS, reason="Linked views unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_create_linked_view_homogeneous_schema_tree_tree(self):
         view_prefix = os.path.join(self._tmp_pr, "view")
         a_vals = range(10)
@@ -1680,7 +1702,7 @@ def test_create_linked_view_homogeneous_schema_tree_tree(self):
                         )
                     )
 
-    @pytest.mark.skipif(WINDOWS, reason="Linked views unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_create_linked_view_homogeneous_schema_tree_flat(self):
         view_prefix = os.path.join(self._tmp_pr, "view")
         a_vals = range(10)
@@ -1707,7 +1729,7 @@ def test_create_linked_view_homogeneous_schema_tree_flat(self):
                         )
                     )
 
-    @pytest.mark.skipif(WINDOWS, reason="Linked views unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_create_linked_view_homogeneous_schema_flat_flat(self):
         view_prefix = os.path.join(self._tmp_pr, "view")
         a_vals = range(10)
@@ -1734,7 +1756,7 @@ def test_create_linked_view_homogeneous_schema_flat_flat(self):
                         )
                     )
 
-    @pytest.mark.skipif(WINDOWS, reason="Linked views unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_create_linked_view_homogeneous_schema_flat_tree(self):
         view_prefix = os.path.join(self._tmp_pr, "view")
         a_vals = range(10)
@@ -1769,7 +1791,7 @@ def test_create_linked_view_homogeneous_schema_flat_tree(self):
                             )
                         )
 
-    @pytest.mark.skipif(WINDOWS, reason="Linked views unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_create_linked_view_homogeneous_schema_nested(self):
         view_prefix = os.path.join(self._tmp_pr, "view")
         a_vals = range(2)
@@ -1801,7 +1823,7 @@ def test_create_linked_view_homogeneous_schema_nested(self):
                         )
                     )
 
-    @pytest.mark.skipif(WINDOWS, reason="Linked views unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_create_linked_view_homogeneous_schema_nested_provide_partial_path(self):
         view_prefix = os.path.join(self._tmp_pr, "view")
         a_vals = range(2)
@@ -1841,7 +1863,7 @@ def test_create_linked_view_homogeneous_schema_nested_provide_partial_path(self)
                         )
                     )
 
-    @pytest.mark.skipif(WINDOWS, reason="Linked views unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_create_linked_view_heterogeneous_disjoint_schema(self):
         view_prefix = os.path.join(self._tmp_pr, "view")
         a_vals = range(5)
@@ -1871,7 +1893,7 @@ def test_create_linked_view_heterogeneous_disjoint_schema(self):
                     os.path.join(view_prefix, "c", sp["c"], "a", str(sp["a"]), "job")
                 )
 
-    @pytest.mark.skipif(WINDOWS, reason="Linked views unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_create_linked_view_heterogeneous_disjoint_schema_nested(self):
         view_prefix = os.path.join(self._tmp_pr, "view")
         a_vals = range(2)
@@ -1902,7 +1924,7 @@ def test_create_linked_view_heterogeneous_disjoint_schema_nested(self):
                     )
                 )
 
-    @pytest.mark.skipif(WINDOWS, reason="Linked views unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_create_linked_view_heterogeneous_fizz_schema_flat(self):
         view_prefix = os.path.join(self._tmp_pr, "view")
         a_vals = range(5)
@@ -1943,7 +1965,7 @@ def test_create_linked_view_heterogeneous_fizz_schema_flat(self):
                             )
                         )
 
-    @pytest.mark.skipif(WINDOWS, reason="Linked views unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_create_linked_view_heterogeneous_schema_nested(self):
         view_prefix = os.path.join(self._tmp_pr, "view")
         a_vals = range(5)
@@ -1979,7 +2001,7 @@ def test_create_linked_view_heterogeneous_schema_nested(self):
                         )
                     )
 
-    @pytest.mark.skipif(WINDOWS, reason="Linked views unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_create_linked_view_heterogeneous_schema_nested_partial_homogenous_path_provide(
         self,
     ):
@@ -2028,25 +2050,27 @@ def test_create_linked_view_heterogeneous_schema_nested_partial_homogenous_path_
                         )
                     )
 
-    @pytest.mark.skipif(WINDOWS, reason="Linked views unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_create_linked_view_heterogeneous_schema_problematic(self):
         self.project.open_job(dict(a=1)).init()
         self.project.open_job(dict(a=1, b=1)).init()
         view_prefix = os.path.join(self._tmp_pr, "view")
         with pytest.raises(RuntimeError):
             self.project.create_linked_view(view_prefix)
 
-    @pytest.mark.skipif(WINDOWS, reason="Linked views unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_create_linked_view_with_slash_raises_error(self):
         statepoint = {"b": f"bad{os.sep}val"}
         view_prefix = os.path.join(self._tmp_pr, "view")
         self.project.open_job(statepoint).init()
         with pytest.raises(RuntimeError):
             self.project.create_linked_view(prefix=view_prefix)
 
-    @pytest.mark.skipif(WINDOWS, reason="Linked views unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_create_linked_view_weird_chars_in_file_name(self):
-        shell_escaped_chars = [" ", "*", "~"]
+        shell_escaped_chars = [" ", "~"]
+        if not WINDOWS:
+            shell_escaped_chars.append("*")
         statepoints = [
             {f"a{i}b": 0, "b": f"escaped{i}val"} for i in shell_escaped_chars
         ]
@@ -2055,7 +2079,7 @@ def test_create_linked_view_weird_chars_in_file_name(self):
             self.project.open_job(sp).init()
             self.project.create_linked_view(prefix=view_prefix)
 
-    @pytest.mark.skipif(WINDOWS, reason="Linked views unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_create_linked_view_duplicate_paths(self):
         view_prefix = os.path.join(self._tmp_pr, "view")
         a_vals = range(2)
@@ -2268,7 +2292,7 @@ def test_get_job_nested_project_subdir(self):
         assert project.get_job(job.fn("test_subdir")) == job
         assert signac.get_job(job.fn("test_subdir")) == job
 
-    @pytest.mark.skipif(WINDOWS, reason="Symbolic links are unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_get_job_symlink_other_project(self):
         # Test case: Get a job from a symlink in another project workspace
         path = self._tmp_dir.name

tests/test_shell.py

@@ -9,14 +9,11 @@
 from tempfile import TemporaryDirectory
 
 import pytest
-from test_project import _initialize_v1_project
+from test_project import WINDOWS, _initialize_v1_project, skip_windows_without_symlinks
 
 import signac
 from signac._config import USER_CONFIG_FN, _Config, _load_config, _read_config_file
 
-# Skip linked view tests on Windows
-WINDOWS = sys.platform == "win32"
-
 
 class DummyFile:
     "We redirect sys stdout into this file during console tests."
@@ -154,7 +151,7 @@ def test_document(self):
             assert str(key) in out
             assert str(value) in out
 
-    @pytest.mark.skipif(WINDOWS, reason="Symbolic links are unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_view_single(self):
         """Check whether command line views work for single job workspaces."""
         self.call("python -m signac init".split())
@@ -170,7 +167,7 @@ def test_view_single(self):
                 project.open_job(sp).path
             )
 
-    @pytest.mark.skipif(WINDOWS, reason="Symbolic links are unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_view(self):
         self.call("python -m signac init".split())
         project = signac.Project()
@@ -186,7 +183,7 @@ def test_view(self):
                 "view/a/{}/job".format(sp["a"])
             ) == os.path.realpath(project.open_job(sp).path)
 
-    @pytest.mark.skipif(WINDOWS, reason="Symbolic links are unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_view_prefix(self):
         self.call("python -m signac init".split())
         project = signac.Project()
@@ -202,7 +199,7 @@ def test_view_prefix(self):
                 "view/test_dir/a/{}/job".format(sp["a"])
             ) == os.path.realpath(project.open_job(sp).path)
 
-    @pytest.mark.skipif(WINDOWS, reason="Symbolic links are unsupported on Windows.")
+    @skip_windows_without_symlinks
     def test_view_incomplete_path_spec(self):
         self.call("python -m signac init".split())
         project = signac.Project()