diff tests/test-rust-ancestor.py @ 50979:4c5f6e95df84

rust: make `Revision` a newtype

This change is the one we've been building towards during this series.
The aim is to make `Revision` mean more than a simple integer, holding
the information that it is valid for a given revlog index.
While this still allows for programmer error, since creating a revision
directly and querying a different index with a "checked" revision are
still possible, the friction created by the newtype will hopefully make
us think twice about which type to use.

Enough of the Rust ecosystem relies on the newtype pattern to be
efficiently optimized away (even compiler in codegen tests¹), so I'm not
worried about this being a fundamental problem.

[1] https://github.com/rust-lang/rust/blob/7a70647f195f6b0a0f1ebd72b1542ba91a32f43a/tests/codegen/vec-in-place.rs#L47

--- a/tests/test-rust-ancestor.py	Thu Aug 10 11:01:07 2023 +0200
+++ b/tests/test-rust-ancestor.py	Fri Aug 18 14:34:29 2023 +0200
@@ -2,7 +2,6 @@
 import unittest
 
 from mercurial.node import wdirrev
-from mercurial import error
 
 from mercurial.testing import revlog as revlogtesting
 
@@ -144,11 +143,15 @@
 
     def testwdirunsupported(self):
         # trying to access ancestors of the working directory raises
-        # WdirUnsupported directly
         idx = self.parseindex()
-        with self.assertRaises(error.WdirUnsupported):
+        with self.assertRaises(rustext.GraphError) as arc:
             list(AncestorsIterator(idx, [wdirrev], -1, False))
 
+        exc = arc.exception
+        self.assertIsInstance(exc, ValueError)
+        # rust-cpython issues appropriate str instances for Python 2 and 3
+        self.assertEqual(exc.args, ('InvalidRevision', wdirrev))
+
     def testheadrevs(self):
         idx = self.parseindex()
         self.assertEqual(dagop.headrevs(idx, [1, 2, 3]), {3})