fix(release): the package version and the tag that installs it must agree

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "views-postprocessing"
-version = "1.0.0"
+version = "1.1.0"
 description = ""
 authors = [
     "Dylan Pinheiro <dylpin@prio.org>",

tests/test_release_version.py

@@ -0,0 +1,81 @@
+"""The package version and the git tag that installs it must agree.
+
+Consumers install this package by tag — `views-models`' launchers do exactly that — and
+then read `importlib.metadata.version(...)` to decide what the installed build can do
+(views-models#294). So the number in `pyproject.toml` is what a consumer *believes* it
+installed, and the tag is what it *actually* installed. Nothing compared them.
+
+Measured 2026-08-13: tag `1.1.0` was cut at `main` while `pyproject.toml` still said
+`1.0.0`, so an install from that tag reported the previous release. Caught before any
+consumer pinned. Third time in this arc a version has been declared twice with a guard on
+one copy (register C-80, C-82).
+"""
+
+import re
+import subprocess
+from pathlib import Path
+
+import pytest
+
+_REPO = Path(__file__).resolve().parent.parent
+
+
+def _declared_version() -> str:
+    text = (_REPO / "pyproject.toml").read_text()
+    match = re.search(r'^version = "([^"]+)"', text, re.M)
+    assert match, (
+        "pyproject.toml no longer declares a version in the form this guard reads. If the "
+        "packaging changed, teach this test the new form — do not delete it, or the number "
+        "a consumer installs goes unchecked again."
+    )
+    return match.group(1)
+
+
+def _tags_at(commit: str) -> list[str]:
+    out = subprocess.run(
+        ["git", "-C", str(_REPO), "tag", "--points-at", commit],
+        capture_output=True, text=True, check=False, timeout=30,
+    )
+    return sorted(t for t in out.stdout.split() if re.fullmatch(r"\d+\.\d+\.\d+", t))
+
+
+def test_a_release_tag_declares_the_version_the_package_declares():
+    """If HEAD carries a release tag, `pyproject.toml` must say the same number.
+
+    Silent off a tagged commit — most commits are not releases, and firing on them would
+    be the false alarm that gets a guard deleted (ADR-014 §3).
+    """
+    tags = _tags_at("HEAD")
+    if not tags:
+        pytest.skip("HEAD carries no release tag; nothing to compare")
+
+    declared = _declared_version()
+    assert tags == [declared], (
+        f"HEAD is tagged {tags} but pyproject.toml declares {declared!r}. A consumer "
+        "installing by tag would read the wrong version from importlib.metadata, which is "
+        "what views-models#294's capability assert reads. Bump the file and re-point the "
+        "tag, or tag a commit that already carries the right number."
+    )
+
+
+def test_the_newest_release_tag_is_not_ahead_of_the_declared_version():
+    """A tag newer than the file means a release was cut without bumping.
+
+    This is the direction that actually bit: the tag moved, the file did not. Runs on
+    every commit, not only tagged ones, so the gap is visible the moment it opens.
+    """
+    out = subprocess.run(
+        ["git", "-C", str(_REPO), "tag", "-l", "--sort=-v:refname"],
+        capture_output=True, text=True, check=False, timeout=30,
+    )
+    releases = [t for t in out.stdout.split() if re.fullmatch(r"\d+\.\d+\.\d+", t)]
+    if not releases:
+        pytest.skip("no release tags in this checkout (a shallow clone, or none cut yet)")
+
+    newest, declared = releases[0], _declared_version()
+    as_tuple = lambda v: tuple(int(p) for p in v.split("."))  # noqa: E731
+    assert as_tuple(newest) <= as_tuple(declared), (
+        f"the newest release tag is {newest} but pyproject.toml declares {declared}. A "
+        "release was cut without bumping the file, so an install from that tag reports a "
+        "version older than itself."
+    )