Add _constraints_to_uv: turn resolved constraints into uv array items

Author: jensens

src/mxdev/uv.py

@@ -15,6 +15,36 @@
 logger = logging.getLogger("mxdev")
 
 
+def _constraints_to_uv(constraints: list[str]) -> list[tuple[str, str]]:
+    """Turn resolved constraint lines into ordered uv array items.
+
+    Mirrors ``constraints-mxdev.txt`` into TOML-array form: specifier lines
+    become ``("entry", specifier)`` and comment lines become
+    ``("comment", text)``, preserving source order. Decorative ``####`` rules,
+    blank lines, and non-PEP-508 lines (e.g. ``--hash``) are dropped.
+    """
+    from packaging.requirements import Requirement
+
+    items: list[tuple[str, str]] = []
+    for raw in constraints:
+        stripped = raw.strip()
+        if not stripped:
+            continue
+        # Decorative full-width rule (line consisting only of '#').
+        if set(stripped) == {"#"}:
+            continue
+        if stripped.startswith("#"):
+            items.append(("comment", stripped.lstrip("#").strip()))
+            continue
+        try:
+            Requirement(stripped)
+        except Exception:
+            logger.debug("[uv] Skipping non-PEP-508 constraint line: %s", stripped)
+            continue
+        items.append(("entry", stripped))
+    return items
+
+
 class UvPyprojectUpdater(Hook):
     """An mxdev hook that updates pyproject.toml during the write phase for uv-managed projects."""
 

tests/test_uv.py

@@ -1,5 +1,6 @@
 from mxdev.config import Configuration
 from mxdev.state import State
+from mxdev.uv import _constraints_to_uv
 from mxdev.uv import UvPyprojectUpdater
 
 import pytest
@@ -459,3 +460,30 @@ def fake_import(name, *args, **kw):
 
     # Should not raise any error, even though tomlkit import is mocked to fail
     hook.write(state)
+
+
+def test_constraints_to_uv_filters_and_preserves_order():
+    constraints = [
+        "#" * 79 + "\n",
+        "# begin constraints from: https://example.com/a.txt\n",
+        "\n",
+        "Zope==6.0\n",
+        "# AccessControl==7.3 -> mxdev disabled (source)\n",
+        'backports.tarfile==1.2.0 ; python_version < "3.12"\n',
+        "--hash=sha256:deadbeef\n",
+        "# end constraints from: https://example.com/a.txt\n",
+        "#" * 79 + "\n",
+    ]
+    result = _constraints_to_uv(constraints)
+    assert result == [
+        ("comment", "begin constraints from: https://example.com/a.txt"),
+        ("entry", "Zope==6.0"),
+        ("comment", "AccessControl==7.3 -> mxdev disabled (source)"),
+        ("entry", 'backports.tarfile==1.2.0 ; python_version < "3.12"'),
+        ("comment", "end constraints from: https://example.com/a.txt"),
+    ]
+
+
+def test_constraints_to_uv_empty_input():
+    assert _constraints_to_uv([]) == []
+    assert _constraints_to_uv(["\n", "#" * 79 + "\n", "   \n"]) == []