Add support for .hg_archival.txt files

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## Unreleased
 
 * Added a `strict` option to prevent falling back to `0.0.0` when there are no tags.
+* Added support for `.hg_archival.txt` files (created by `hg archive`).
 
 ## v1.13.2 (2022-10-14)
 

dunamai/__init__.py

@@ -299,6 +299,23 @@ def _detect_vcs(expected_vcs: Optional[Vcs] = None) -> Vcs:
         raise RuntimeError("Unable to detect version control system.")
 
 
+def _find_higher_file(name: str, limit: Optional[str] = None, start: Path = None) -> Optional[Path]:
+    """
+    :param name: Bare name of a file we'd like to find.
+    :param limit: Give up if we find a file/folder with this name.
+    :param start: Begin recursing from this folder (default: `.`).
+    """
+
+    if start is None:
+        start = Path.cwd()
+    for level in [start, *start.parents]:
+        if (level / name).is_file():
+            return level / name
+        if limit is not None and (level / limit).exists():
+            return None
+    return None
+
+
 class _GitRefInfo:
     def __init__(
         self, ref: str, commit: str, creatordate: str, committerdate: str, taggerdate: str
@@ -933,6 +950,53 @@ def from_mercurial(
         :param full_commit: Get the full commit hash instead of the short form.
         :param strict: When there are no tags, fail instead of falling back to 0.0.0.
         """
+        archival = _find_higher_file(".hg_archival.txt", ".hg")
+        if archival is not None:
+            content = archival.read_text("utf8")
+            data = {}
+            for line in content.splitlines():
+                parts = line.split(":", 1)
+                if len(parts) != 2:
+                    continue
+                data[parts[0].strip()] = parts[1].strip()
+
+            tag = data.get("latesttag")
+            # The distance is 1 on a new repo or on a tagged commit.
+            distance = int(data.get("latesttagdistance", 1)) - 1
+            commit = data.get("node")
+            branch = data.get("branch")
+
+            if tag is None or tag == "null":
+                return cls._fallback(strict, distance=distance, commit=commit, branch=branch)
+
+            all_tags_file = _find_higher_file(".hgtags", ".hg")
+            if all_tags_file is None:
+                all_tags = [tag]
+            else:
+                all_tags = []
+                all_tags_content = all_tags_file.read_text("utf8")
+                for line in reversed(all_tags_content.splitlines()):
+                    parts = line.split(" ", 1)
+                    if len(parts) != 2:
+                        continue
+                    all_tags.append(parts[1])
+
+            tag, base, stage, unmatched, tagged_metadata, epoch = _match_version_pattern(
+                pattern, all_tags, latest_tag
+            )
+            version = cls(
+                base,
+                stage=stage,
+                distance=distance,
+                commit=commit,
+                tagged_metadata=tagged_metadata,
+                epoch=epoch,
+                branch=branch,
+            )
+            version._matched_tag = tag
+            version._newer_unmatched_tags = unmatched
+            return version
+
         _detect_vcs(Vcs.Mercurial)
 
         code, msg = _run_cmd("hg summary")

tests/integration/archival-hg-tagged/.hg_archival.txt

@@ -0,0 +1,6 @@
+repo: 25e474af1332ed4fff9351c70ef8f36352c013f2
+node: cf36273384e558411364a3a973aaa0cc08e48aea
+branch: default
+latesttag: foo bar
+latesttagdistance: 1
+changessincelatesttag: 1

tests/integration/archival-hg-tagged/.hgtags

@@ -0,0 +1,3 @@
+d80ce21ea5d88b577ee32661ffd3a5b3834f14e0 v0.1.0
+5255faf9dfb276bbe189562e9a1194f43506c21c v0.1.1
+1662f75d4df8f05506c2bc9d9801f80d879bf3f0 foo bar

tests/integration/archival-hg-untagged/.hg_archival.txt

@@ -0,0 +1,6 @@
+repo: 25e474af1332ed4fff9351c70ef8f36352c013f2
+node: 25e474af1332ed4fff9351c70ef8f36352c013f2
+branch: default
+latesttag: null
+latesttagdistance: 1
+changessincelatesttag: 1

tests/integration/test_dunamai.py

@@ -15,6 +15,9 @@ def avoid_identical_ref_timestamps() -> None:
     time.sleep(1.2)
 
 
+REPO = Path(__file__).parent.parent.parent
+
+
 @contextmanager
 def chdir(where: Path) -> Iterator[None]:
     start = Path.cwd()
@@ -426,6 +429,33 @@ def test__version__from_mercurial(tmp_path) -> None:
         assert from_vcs(latest_tag=True) == Version("0.1.0", dirty=False, branch=b)
 
 
+def test__version__from_mercurial__archival_untagged() -> None:
+    with chdir(REPO / "tests" / "integration" / "archival-hg-untagged"):
+        detected = Version.from_mercurial()
+        assert detected == Version(
+            "0.0.0",
+            branch="default",
+            commit="25e474af1332ed4fff9351c70ef8f36352c013f2",
+        )
+        assert detected._matched_tag is None
+        assert detected._newer_unmatched_tags is None
+
+        with pytest.raises(RuntimeError):
+            Version.from_mercurial(strict=True)
+
+
+def test__version__from_mercurial__archival_tagged() -> None:
+    with chdir(REPO / "tests" / "integration" / "archival-hg-tagged"):
+        detected = Version.from_mercurial()
+        assert detected == Version(
+            "0.1.1",
+            branch="default",
+            commit="cf36273384e558411364a3a973aaa0cc08e48aea",
+        )
+        assert detected._matched_tag == "v0.1.1"
+        assert detected._newer_unmatched_tags == ["foo bar"]
+
+
 @pytest.mark.skipif(shutil.which("darcs") is None, reason="Requires Darcs")
 def test__version__from_darcs(tmp_path) -> None:
     vcs = tmp_path / "dunamai-darcs"