Fix length validation error on HookName deletion (#71)

packages/xahau/HISTORY.md

@@ -2,6 +2,9 @@
 
 ## Unreleased Changes
 
+### Fixed
+* Fix HookName validation on HookName deletion
+
 ## 4.1.0 (2026-06-23)
 
 ### Added

packages/xahau/src/models/transactions/setHook.ts

@@ -79,7 +79,11 @@ export function validateSetHook(tx: Record<string, unknown>): void {
         `SetHook: HookNamespace in Hook must be a 256-bit (32-byte) hexadecimal value`,
       )
     }
-    if (HookName !== undefined && !HOOKNAME_REGEX.test(HookName)) {
+    if (
+      HookName !== undefined &&
+      HookName.length !== 0 &&
+      !HOOKNAME_REGEX.test(HookName)
+    ) {
       throw new ValidationError(
         `SetHook: HookName in Hook must be a hex string of 8-32 hex characters`,
       )

packages/xahau/test/integration/transactions/setHook.test.ts

@@ -135,4 +135,49 @@ describe('SetHook', function () {
     },
     TIMEOUT,
   )
+
+  it('hook name update', async () => {
+    let setHookTx: SetHook = {
+      TransactionType: 'SetHook',
+      Account: wallet.classicAddress,
+      Hooks: [
+        {
+          Hook: {
+            CreateCode: acceptHook,
+            HookApiVersion: 0,
+            HookName: '484F4F4B',
+            HookOn: '00'.repeat(32),
+            HookNamespace: '00'.repeat(32),
+          },
+        },
+      ],
+    }
+    await testTransaction(testContext.client, setHookTx, wallet)
+    {
+      const ledgerEntryResponse = await testContext.client.request({
+        command: 'ledger_entry',
+        hook: { account: wallet.classicAddress },
+      })
+      const node = ledgerEntryResponse.result.node as Hook
+      const hook = node.Hooks[0].Hook
+      expect(hook.HookName).toEqual('484F4F4B')
+    }
+
+    // delete HookName
+    setHookTx = {
+      TransactionType: 'SetHook',
+      Account: wallet.classicAddress,
+      Hooks: [{ Hook: { HookName: '' } }],
+    }
+    await testTransaction(testContext.client, setHookTx, wallet)
+    {
+      const ledgerEntryResponse = await testContext.client.request({
+        command: 'ledger_entry',
+        hook: { account: wallet.classicAddress },
+      })
+      const node = ledgerEntryResponse.result.node as Hook
+      const hook = node.Hooks[0].Hook
+      expect(hook.HookName).toBeUndefined()
+    }
+  })
 })

packages/xahau/test/models/setHook.test.ts

@@ -175,7 +175,7 @@ describe('SetHook', function () {
     assert.throws(() => validate(setHookTx), ValidationError, errorMessage)
   })
 
-  it.each(['', '0'.repeat(7), '0'.repeat(33), 'ZZZZZZZZ'])(
+  it.each(['00', '0000', '000000', '0'.repeat(7), '0'.repeat(33), 'ZZZZZZZZ'])(
     `throws w/ invalid HookName in Hooks: %s`,
     function (value: string) {
       setHookTx.Hooks = [
@@ -195,4 +195,16 @@ describe('SetHook', function () {
       assert.throws(() => validate(setHookTx), ValidationError, errorMessage)
     },
   )
+
+  it(`valid HookName "" (deletion) in Hooks`, function () {
+    setHookTx.Hooks = [
+      {
+        Hook: {
+          HookName: '',
+        },
+      },
+    ]
+    assert.doesNotThrow(() => validateSetHook(setHookTx))
+    assert.doesNotThrow(() => validate(setHookTx))
+  })
 })