fix: handle unknown alembic revisions during startup

documentation/changelog.rst

@@ -33,6 +33,7 @@ Bugfixes
 * KPIs on the asset page counted one day more than the selected time range [see `PR #2434 <https://www.github.com/FlexMeasures/flexmeasures/pull/2434>`_]
 * KPIs on the asset page now total the values the chart beside them draws, counting each event under the day it starts in: a sensor reported by several sources counted only one of them, and a revised value was counted on top of the value it revised [see `PR #2434 <https://www.github.com/FlexMeasures/flexmeasures/pull/2434>`_]
 * The time range sent when loading an asset's KPIs was off by the viewer's UTC offset, so KPIs could cover the wrong days [see `PR #2435 <https://www.github.com/FlexMeasures/flexmeasures/pull/2435>`_]
+* Avoid crashing on startup when the database is stamped with an Alembic revision unknown to this FlexMeasures checkout [see `PR #2465 <https://www.github.com/FlexMeasures/flexmeasures/pull/2465>`_]
 
 
 

flexmeasures/data/tests/test_utils.py

@@ -2,6 +2,7 @@
 
 import logging
 
+from alembic.script.revision import ResolutionError
 from sqlalchemy.exc import OperationalError, ProgrammingError
 
 from flexmeasures.data import db, register_at
@@ -54,12 +55,25 @@ def iterate_revisions(self, *args, **kwargs):
         return (_DummyRevision(revision) for revision in self._revisions)
 
 
+class _DummyRevisionMapWithUnknownRevision:
+    def iterate_revisions(self, *args, **kwargs):
+        def revisions():
+            raise ResolutionError("No such revision or branch 'unknown-a'", "unknown-a")
+            yield
+
+        return revisions()
+
+
 class _DummyScriptDirectoryWithRevisionMap(_DummyScriptDirectory):
     def __init__(self, heads: tuple[str, ...], revisions: tuple[str, ...]):
         super().__init__(heads)
         self.revision_map = _DummyRevisionMap(revisions)
 
 
+class _DummyScriptDirectoryWithUnknownRevisionMap(_DummyScriptDirectory):
+    revision_map = _DummyRevisionMapWithUnknownRevision()
+
+
 def test_schema_mismatch_log_record_is_deduplicated(
     app, clean_redis, monkeypatch, caplog
 ):
@@ -237,3 +251,19 @@ def test_database_schema_has_revision_false_when_revision_is_not_in_current_hist
     )
 
     assert database_schema_has_revision(app, "required-a") is False
+
+
+def test_database_schema_has_revision_false_when_current_revision_is_unknown(
+    app, monkeypatch
+):
+    monkeypatch.setattr(db.engine, "connect", lambda: _DummyConnection())
+    monkeypatch.setattr(
+        "flexmeasures.data.utils.MigrationContext.configure",
+        lambda connection: _DummyMigrationContext(("unknown-a",)),
+    )
+    monkeypatch.setattr(
+        "flexmeasures.data.utils.ScriptDirectory.from_config",
+        lambda config: _DummyScriptDirectoryWithUnknownRevisionMap(("head-a",)),
+    )
+
+    assert database_schema_has_revision(app, "required-a") is False

flexmeasures/data/utils.py

@@ -112,10 +112,10 @@ def database_schema_has_revision(app, required_revision: str) -> bool:
                 inclusive=True,
                 assert_relative_length=False,
             )
+            if any(revision.revision == required_revision for revision in revisions):
+                return True
         except RevisionError:
             continue
-        if any(revision.revision == required_revision for revision in revisions):
-            return True
     return False