refactor(pg-delta): use invalidates for policy replacement

RED: after rebasing onto supabase#273, the design regression using a generic invalidating change failed in expand-replace-dependencies.test.ts with Expected: true / Received: false for DropRlsPolicy because the helper still checked AlterTableAlterColumnType directly.

GREEN: expand-replace-dependencies.test.ts now passes, PG17 policy-dependencies.test.ts focused and full-file runs pass, and format-and-lint/check-types/knip pass.
Signed-off-by: xiaominghao <xiaominghao@baidu.com>

Author: xmh1011

packages/pg-delta/src/core/expand-replace-dependencies.test.ts

@@ -20,7 +20,6 @@ import { diffSequences } from "./objects/sequence/sequence.diff.ts";
 import { Sequence } from "./objects/sequence/sequence.model.ts";
 import {
   AlterTableAlterColumnSetDefault,
-  AlterTableAlterColumnType,
   AlterTableChangeOwner,
   AlterTableDropColumn,
   AlterTableDropConstraint,
@@ -49,6 +48,7 @@ function mockChange(overrides: {
     scope: "object",
     creates,
     drops,
+    invalidates: [],
     requires: [],
     table: { schema: "public", name: "t" },
     serialize: () => [],
@@ -58,6 +58,20 @@ function mockChange(overrides: {
   } as unknown as Change;
 }
 
+function mockInvalidatingChange(invalidates: string[]): Change {
+  return {
+    objectType: "table",
+    operation: "alter",
+    scope: "object",
+    creates: [],
+    drops: [],
+    invalidates,
+    requires: [],
+    table: { schema: "public", name: "t" },
+    serialize: () => "",
+  } as unknown as Change;
+}
+
 describe("expandReplaceDependencies", () => {
   test("returns changes unchanged when there are no replace roots", async () => {
     const catalog = await createEmptyCatalog(160004, "u");
@@ -826,7 +840,7 @@ describe("expandReplaceDependencies", () => {
     ).toBe(true);
   });
 
-  test("promotes dependent RLS policy when a referenced column is rewritten", async () => {
+  test("promotes dependent RLS policy when a referenced column is invalidated", async () => {
     const baseline = await createEmptyCatalog(170000, "postgres");
     const columnTemplate = {
       position: 1,
@@ -922,11 +936,9 @@ describe("expandReplaceDependencies", () => {
       withCheckExpression: branchPolicy.with_check_expression,
     });
     const changes: Change[] = [
-      new AlterTableAlterColumnType({
-        table: branchTable,
-        column: branchRoleColumn,
-        previousColumn: mainRoleColumn,
-      }),
+      mockInvalidatingChange([
+        "column:public.solution_categories_with_policy.role",
+      ]),
       alterUsing,
       alterWithCheck,
     ];

packages/pg-delta/src/core/expand-replace-dependencies.ts

@@ -13,10 +13,7 @@ import { DropProcedure } from "./objects/procedure/changes/procedure.drop.ts";
 import { CreateCommentOnRlsPolicy } from "./objects/rls-policy/changes/rls-policy.comment.ts";
 import { CreateRlsPolicy } from "./objects/rls-policy/changes/rls-policy.create.ts";
 import { DropRlsPolicy } from "./objects/rls-policy/changes/rls-policy.drop.ts";
-import {
-  AlterTableAddConstraint,
-  AlterTableAlterColumnType,
-} from "./objects/table/changes/table.alter.ts";
+import { AlterTableAddConstraint } from "./objects/table/changes/table.alter.ts";
 import { CreateCommentOnConstraint } from "./objects/table/changes/table.comment.ts";
 import { CreateTable } from "./objects/table/changes/table.create.ts";
 import { DropTable } from "./objects/table/changes/table.drop.ts";
@@ -127,7 +124,7 @@ export function expandReplaceDependencies({
   }
 
   const promotedRlsPolicyIds = new Set<string>();
-  const additions: Change[] = collectColumnRewritePolicyReplacements({
+  const additions: Change[] = collectInvalidatedRlsPolicyReplacements({
     changes,
     mainCatalog,
     branchCatalog,
@@ -304,7 +301,7 @@ export function expandReplaceDependencies({
   };
 }
 
-function collectColumnRewritePolicyReplacements({
+function collectInvalidatedRlsPolicyReplacements({
   changes,
   mainCatalog,
   branchCatalog,
@@ -319,22 +316,22 @@ function collectColumnRewritePolicyReplacements({
   droppedIds: Set<string>;
   promotedRlsPolicyIds: Set<string>;
 }): Change[] {
-  const rewrittenColumnIds = new Set<string>();
+  // In-place rewrites report stable ids through `invalidates`: the referenced
+  // object keeps its identity, but dependents bound to the old definition must
+  // be torn down first. RLS policy expressions are tracked in pg_depend, so use
+  // those catalog edges to promote only policies that depend on an invalidated
+  // id, without coupling this expansion pass to a concrete table-change class.
+  const invalidatedIds = new Set<string>();
   for (const change of changes) {
-    if (!(change instanceof AlterTableAlterColumnType)) continue;
-    rewrittenColumnIds.add(
-      stableId.column(
-        change.table.schema,
-        change.table.name,
-        change.column.name,
-      ),
-    );
+    for (const invalidatedId of change.invalidates) {
+      invalidatedIds.add(invalidatedId);
+    }
   }
-  if (rewrittenColumnIds.size === 0) return [];
+  if (invalidatedIds.size === 0) return [];
 
   const replacements: Change[] = [];
   for (const dep of mainCatalog.depends) {
-    if (!rewrittenColumnIds.has(dep.referenced_stable_id)) continue;
+    if (!invalidatedIds.has(dep.referenced_stable_id)) continue;
 
     const targetId = normalizeDependentId(dep.dependent_stable_id);
     if (!targetId?.startsWith("rlsPolicy:")) continue;