Re-enable burn tests on Kusama relay; keep them disabled on Polkadot

Kusama passes at the current known-good block because the AHM accounts
migration has not yet run there, so validator accounts still have free
balance on the relay chain and fee routing via DealWithFees/ToAuthor
succeeds. Polkadot's known-good block is past that migration, leaving
validator accounts with free = 0, which causes ToAuthor to silently
drop the fee credit and reduce TotalIssuance by 0.2 * fee, breaking
the strict equality assertion in the burn tests.

Polkadot tests will be re-enabled once DealWithFees/ToAuthor is fixed
upstream to not drop fee credits when the author account is below ED.
See paritytech/polkadot-sdk#9986.

Author: rockbmb

packages/kusama/src/kusama.accounts.e2e.test.ts

@@ -2,19 +2,14 @@ import { kusama } from '@e2e-test/networks/chains'
 import {
   accountsE2ETests,
   createAccountsConfig,
-  type DescribeNode,
   manualLockAction,
   manualReserveAction,
   multisigCreationDepositAction,
   proxyAdditionDepositAction,
-  type RootTestTree,
   registerTestTree,
   type TestConfig,
-  type TestNode,
 } from '@e2e-test/shared'
 
-import { match } from 'ts-pattern'
-
 const generalTestConfig: TestConfig = {
   testSuiteName: 'Kusama Accounts',
 }
@@ -37,30 +32,4 @@ const accountsTestCfg = createAccountsConfig({
   },
 })
 
-/**
- * `burn` tests are temporarily disabled on Kusama relay, see
- * https://github.com/paritytech/polkadot-sdk/issues/9986.
- *
- * TODO: reenable after fix
- */
-const filterOutBurnTests = (tree: RootTestTree): RootTestTree => {
-  const filterChildren = (children: (TestNode | DescribeNode)[]): (TestNode | DescribeNode)[] => {
-    return children
-      .filter((child) => !child.label.includes('burn'))
-      .map((child) => {
-        return match(child)
-          .with({ kind: 'test' }, () => child)
-          .with({ kind: 'describe' }, (desc) => {
-            return { ...desc, children: filterChildren(desc.children) }
-          })
-          .exhaustive()
-      })
-  }
-
-  return {
-    ...tree,
-    children: filterChildren(tree.children),
-  }
-}
-
-registerTestTree(filterOutBurnTests(accountsE2ETests(kusama, generalTestConfig, accountsTestCfg)))
+registerTestTree(accountsE2ETests(kusama, generalTestConfig, accountsTestCfg))

packages/polkadot/src/polkadot.accounts.e2e.test.ts

@@ -37,6 +37,24 @@ const accountsTestCfg = createAccountsConfig({
   },
 })
 
+// `burn` tests are disabled on Polkadot relay. See https://github.com/paritytech/polkadot-sdk/issues/9986.
+//
+// Root cause: post-AHM, most validator relay-chain accounts have small or zero residual
+// free balances. `DealWithFees` routes 20% of every tx fee to the block author via
+// `ToAuthor`; `pallet_balances::resolve` rejects deposits below ED, silently drops the
+// `Credit`, and `TotalIssuance` shrinks by `0.2 × fee`. The burn tests assert strict TI
+// equality, so they fail by exactly that amount.
+//
+// Whether this manifests depends on the specific block author's free balance vs ED:
+//   - Polkadot ED = 10,000,000,000 Planck (1 DOT): most post-AHM validator balances are
+//     below this, so the deposit fails consistently at the current known-good block.
+//   - Kusama ED = 333,333,333 Planck (~0.033 KSM): smaller, so the author at the current
+//     Kusama known-good block happens to clear it — but Kusama will fail too if its
+//     known-good block is updated to one where the author's balance is below that ED.
+//
+// The correct fix is upstream: `DealWithFees`/`ToAuthor` must not silently drop the fee
+// credit when the author account is below ED (e.g. route to treasury instead).
+// TODO: remove this filter once that is resolved.
 const filterOutBurnTests = (tree: RootTestTree): RootTestTree => {
   const filterChildren = (children: (TestNode | DescribeNode)[]): (TestNode | DescribeNode)[] => {
     return children