pyln: Add a version parser to pyln-testing

We changed the way we configure CLN to run in developer mode, which
promptly broke anything that wasn't v23.11 and later. So we parse the
version, and make it comparable, so we can determine what to do on the
fly, and maintain a better backwards compatibility.

Changelog-Changed: pyln-testing: pyln-testing is now version-aware and can customize the run based on the version.

contrib/pyln-testing/pyln/testing/version.py

@@ -0,0 +1,37 @@
+
+from dataclasses import dataclass
+import re
+
+
+@dataclass
+class Version:
+    year: int
+    month: int
+    patch: int = 0
+
+    def __lt__(self, other):
+        return [self.year, self.month, self.patch] < [other.year, other.month, other.patch]
+
+    def __gt__(self, other):
+        return other < self
+
+    def __le__(self, other):
+        return [self.year, self.month, self.patch] <= [other.year, other.month, other.patch]
+
+    def __ge__(self, other):
+        return other <= self
+
+    def __eq__(self, other):
+        return [self.year, self.month] == [other.year, other.month]
+
+    @classmethod
+    def from_str(cls, s: str) -> "Version":
+        m = re.search(r'^v(\d+).(\d+).?(\d+)?(rc\d+)?', s)
+        parts = [int(m.group(i)) for i in range(1, 4) if m.group(i) is not None]
+        year, month = parts[0], parts[1]
+        if len(parts) == 3:
+            patch = parts[2]
+        else:
+            patch = 0
+
+        return Version(year=year, month=month, patch=patch)

contrib/pyln-testing/tests/test_fixtures.py

@@ -0,0 +1,12 @@
+from pyln.testing.version import Version
+
+
+def test_version_parsing():
+    cases = [
+        ("v24.02", Version(24, 2)),
+        ("v23.11.2", Version(23, 11, 2)),
+    ]
+
+    for test_in, test_out in cases:
+        v = Version.from_str(test_in)
+        assert test_out == v