config: resolve: handle ~ home dir

Fixes #9822

dvc/config.py

@@ -250,21 +250,30 @@ class Config(dict):
         return conf
 
     @staticmethod
-    def _load_paths(conf, filename):
-        abs_conf_dir = os.path.abspath(os.path.dirname(filename))
+    def _resolve(conf_dir, path):
+        from .config_schema import ExpPath, RelPath
 
-        def resolve(path):
-            from .config_schema import RelPath
+        if re.match(r"\w+://", path):
+            return path
 
-            if os.path.isabs(path) or re.match(r"\w+://", path):
-                return path
+        if os.path.isabs(path):
+            return path
 
-            # on windows convert slashes to backslashes
-            # to have path compatible with abs_conf_dir
-            if os.path.sep == "\\" and "/" in path:
-                path = path.replace("/", "\\")
+        # on windows convert slashes to backslashes
+        # to have path compatible with abs_conf_dir
+        if os.path.sep == "\\" and "/" in path:
+            path = path.replace("/", "\\")
 
-            return RelPath(os.path.join(abs_conf_dir, path))
+        expanded = os.path.expanduser(path)
+        if os.path.isabs(expanded):
+            return ExpPath(expanded, path)
+
+        return RelPath(os.path.abspath(os.path.join(conf_dir, path)))
+
+    @classmethod
+    def _load_paths(cls, conf, filename):
+        conf_dir = os.path.abspath(os.path.dirname(filename))
+        resolve = partial(cls._resolve, conf_dir)
 
         return Config._map_dirs(conf, resolve)
 
@@ -273,11 +282,17 @@ class Config(dict):
         from dvc.fs import localfs
         from dvc.utils import relpath
 
-        from .config_schema import RelPath
+        from .config_schema import ExpPath, RelPath
 
         if re.match(r"\w+://", path):
             return path
 
+        if isinstance(path, ExpPath):
+            return path.def_path
+
+        if os.path.expanduser(path) != path:
+            return localfs.path.as_posix(path)
+
         if isinstance(path, RelPath) or not os.path.isabs(path):
             path = relpath(path, conf_dir)
             return localfs.path.as_posix(path)

dvc/config_schema.py

@@ -75,6 +75,17 @@ def ByUrl(mapping):  # noqa: N802
     return validate
 
 
+class ExpPath(str):
+    __slots__ = ("def_path",)
+
+    def_path: str
+
+    def __new__(cls, string, def_path):
+        ret = super().__new__(cls, string)
+        ret.def_path = def_path
+        return ret
+
+
 class RelPath(str):
     __slots__ = ()
 

tests/func/test_config.py

@@ -265,14 +265,16 @@ def test_load_relative_paths(dvc, field, remote_url):
 
     # check if written paths are correct
     dvc_dir = dvc.config.dvc_dir
-    assert dvc.config["remote"]["test"][field] == os.path.join(
-        dvc_dir, "..", "file.txt"
+    assert dvc.config["remote"]["test"][field] == os.path.abspath(
+        os.path.join(dvc_dir, "..", "file.txt")
     )
 
     # load config and check that it contains what we expect
     # (relative paths are evaluated correctly)
     cfg = Config(dvc_dir)
-    assert cfg["remote"]["test"][field] == os.path.join(dvc_dir, "..", "file.txt")
+    assert cfg["remote"]["test"][field] == os.path.abspath(
+        os.path.join(dvc_dir, "..", "file.txt")
+    )
 
 
 def test_config_gdrive_fields(tmp_dir, dvc):

tests/unit/test_config.py

@@ -21,6 +21,29 @@ def test_to_relpath(path, expected):
     assert Config._to_relpath(os.path.join(".", "config"), path) == expected
 
 
+@pytest.mark.parametrize(
+    "path, expected",
+    [
+        ("cache", os.path.abspath(os.path.join("conf_dir", "cache"))),
+        ("dir/cache", os.path.abspath(os.path.join("conf_dir", "dir", "cache"))),
+        ("../cache", os.path.abspath("cache")),
+        (os.getcwd(), os.getcwd()),
+        ("ssh://some/path", "ssh://some/path"),
+    ],
+)
+def test_resolve(path, expected):
+    conf_dir = os.path.abspath("conf_dir")
+    assert Config._resolve(conf_dir, path) == expected
+
+
+def test_resolve_homedir():
+    # NOTE: our test suit patches $HOME, but that only works within the
+    # test itself, so we can't use expanduser in @parametrize here.
+    conf_dir = os.path.abspath("conf_dir")
+    expected = os.path.expanduser(os.path.join("~", "cache"))
+    assert Config._resolve(conf_dir, "~/cache") == expected
+
+
 def test_get_fs(tmp_dir, scm):
     tmp_dir.scm_gen("foo", "foo", commit="add foo")