Add :parent path modifier

backend/src/hatchling/utils/context.py

@@ -26,6 +26,19 @@ def format_path(cls, path: str, modifier: str) -> str:
         if not modifier:
             return os.path.normpath(path)
 
+        modifiers = modifier.split(':')[::-1]
+        while modifiers and modifiers[-1] == 'parent':
+            path = os.path.dirname(path)
+            modifiers.pop()
+
+        if not modifiers:
+            return path
+
+        if len(modifiers) > 1:
+            message = f'Expected a single path modifier and instead got: {", ".join(reversed(modifiers))}'
+            raise ValueError(message)
+
+        modifier = modifiers[0]
         if modifier == 'uri':
             return path_to_uri(path)
 

docs/config/context.md

@@ -21,6 +21,17 @@ All paths support the following modifiers:
 | --- | --- |
 | `uri` | The normalized absolute URI path prefixed by `file:` |
 | `real` | The path with all symbolic links resolved |
+| `parent` | The parent of the preceding path |
+
+!!! tip
+    The `parent` modifier can be chained and may be combined with either the `uri` or `real` modifier, with the latter placed at the end. For example:
+
+    ```toml config-example
+    [tool.hatch.envs.test]
+    dependencies = [
+        "example-project @ {root:parent:parent:uri}/example-project",
+    ]
+    ```
 
 ### System separators
 

docs/history/hatchling.md

@@ -13,6 +13,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ***Added:***
 
 - Add `bypass-selection` option to the `wheel` build target to allow for empty (metadata-only) wheels
+- Add `parent` context modifier for path fields
 
 ***Fixed:***
 

tests/backend/utils/test_context.py

@@ -26,21 +26,58 @@ def test_default(self, isolation):
         context = Context(isolation)
         assert context.format('foo {root}') == f'foo {isolation}'
 
+    def test_parent(self, isolation):
+        context = Context(isolation)
+        path = os.path.dirname(str(isolation))
+        assert context.format('foo {root:parent}') == f'foo {path}'
+
+    def test_parent_parent(self, isolation):
+        context = Context(isolation)
+        path = os.path.dirname(os.path.dirname(str(isolation)))
+        assert context.format('foo {root:parent:parent}') == f'foo {path}'
+
     def test_uri(self, isolation, uri_slash_prefix):
         context = Context(isolation)
         normalized_path = str(isolation).replace(os.sep, '/')
         assert context.format('foo {root:uri}') == f'foo file:{uri_slash_prefix}{normalized_path}'
 
+    def test_uri_parent(self, isolation, uri_slash_prefix):
+        context = Context(isolation)
+        normalized_path = os.path.dirname(str(isolation)).replace(os.sep, '/')
+        assert context.format('foo {root:parent:uri}') == f'foo file:{uri_slash_prefix}{normalized_path}'
+
+    def test_uri_parent_parent(self, isolation, uri_slash_prefix):
+        context = Context(isolation)
+        normalized_path = os.path.dirname(os.path.dirname(str(isolation))).replace(os.sep, '/')
+        assert context.format('foo {root:parent:parent:uri}') == f'foo file:{uri_slash_prefix}{normalized_path}'
+
     def test_real(self, isolation):
         context = Context(isolation)
-        assert context.format('foo {root:real}') == f'foo {os.path.realpath(isolation)}'
+        real_path = os.path.realpath(isolation)
+        assert context.format('foo {root:real}') == f'foo {real_path}'
+
+    def test_real_parent(self, isolation):
+        context = Context(isolation)
+        real_path = os.path.dirname(os.path.realpath(isolation))
+        assert context.format('foo {root:parent:real}') == f'foo {real_path}'
+
+    def test_real_parent_parent(self, isolation):
+        context = Context(isolation)
+        real_path = os.path.dirname(os.path.dirname(os.path.realpath(isolation)))
+        assert context.format('foo {root:parent:parent:real}') == f'foo {real_path}'
 
     def test_unknown_modifier(self, isolation):
         context = Context(isolation)
 
         with pytest.raises(ValueError, match='Unknown path modifier: bar'):
             context.format('foo {root:bar}')
 
+    def test_too_many_modifiers_after_parent(self, isolation):
+        context = Context(isolation)
+
+        with pytest.raises(ValueError, match='Expected a single path modifier and instead got: foo, bar, baz'):
+            context.format('foo {root:parent:foo:bar:baz}')
+
 
 class TestHome:
     def test_default(self, isolation):