Fix modifying global that is used in a policy on a type it refers to (#…

…7310)

Fix is simple: we need to call _propagate_if_expr_refs to eliminate
any references to the alias *before* we recompile it, not after.

edb/schema/expraliases.py

@@ -374,6 +374,12 @@ def _alter_begin(
         context: sd.CommandContext,
     ) -> s_schema.Schema:
         if not context.canonical:
+            schema = self._propagate_if_expr_refs(
+                schema,
+                context,
+                action=self.get_friendly_description(schema=schema),
+            )
+
             expr = self.get_attribute_value('expr')
             is_computable = self._is_computable(self.scls, schema)
             if expr:
@@ -415,12 +421,6 @@ def _alter_begin(
                         )
                     )
 
-            schema = self._propagate_if_expr_refs(
-                schema,
-                context,
-                action=self.get_friendly_description(schema=schema),
-            )
-
         return super()._alter_begin(schema, context)
 
 

tests/test_edgeql_data_migration.py

@@ -11336,33 +11336,6 @@ async def test_edgeql_migration_globals_01(self):
         await self.migrate(schema)
         await self.migrate(schema)
 
-    async def test_edgeql_migration_dml_rewrites_01(self):
-        await self.migrate(r"""
-            type Post {
-              required title: str;
-              modified: datetime {
-                rewrite insert, update using (datetime_of_statement())
-              }
-            }
-        """)
-        await self.migrate(r"""
-            type BlogPost {
-              required title: str;
-              modified: datetime {
-                rewrite insert, update using (datetime_of_statement())
-              }
-            }
-        """)
-        await self.migrate(r"""
-            type BlogPost {
-              required title: str;
-              modified: datetime {
-                rewrite insert, update using (datetime_of_transaction())
-              }
-            }
-        """)
-        await self.migrate('')
-
     async def test_edgeql_migration_globals_02(self):
         await self.migrate(r"""
             global current_user_id -> uuid;
@@ -11398,6 +11371,56 @@ async def test_edgeql_migration_globals_02(self):
         await self.migrate(schema)
         await self.migrate(schema)
 
+    async def test_edgeql_migration_globals_03(self):
+        # Test modifying a computed global that is used in an access
+        # policy on the type it refers to.
+        await self.migrate(r"""
+            global cur -> uuid;
+            global scopes := ((select Foo filter .id = global cur).scopes);
+
+            type Foo {
+              multi scopes: str;
+              access policy s allow select using ('f' in global scopes);
+            };
+        """)
+        await self.migrate(r"""
+            global cur -> uuid;
+            global scopes := (
+                select (select Foo filter .id = global cur).scopes);
+
+            type Foo {
+              multi scopes: str;
+              access policy s allow select using ('f' in global scopes);
+            };
+        """)
+
+    async def test_edgeql_migration_dml_rewrites_01(self):
+        await self.migrate(r"""
+            type Post {
+              required title: str;
+              modified: datetime {
+                rewrite insert, update using (datetime_of_statement())
+              }
+            }
+        """)
+        await self.migrate(r"""
+            type BlogPost {
+              required title: str;
+              modified: datetime {
+                rewrite insert, update using (datetime_of_statement())
+              }
+            }
+        """)
+        await self.migrate(r"""
+            type BlogPost {
+              required title: str;
+              modified: datetime {
+                rewrite insert, update using (datetime_of_transaction())
+              }
+            }
+        """)
+        await self.migrate('')
+
     async def test_edgeql_migration_policies_and_collections(self):
         # An infinite recursion bug with this this was found by accident
         # when a number of tests accidentally were in the non isolated test.