feat(keyring-api): add token:disapprove transaction type + new optional details.typeLabel (#568)

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<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Low Risk**
> Additive, backward-compatible schema and enum extensions with
validation tests only; no auth or runtime behavior changes.
> 
> **Overview**
> Extends the Keyring API **transaction** model so snaps and clients can
classify token revocations and show richer activity labels.
> 
> Adds **`TransactionType.TokenDisapprove`** (`token:disapprove`)
alongside the existing `token:approve` type, and wires it into
**`TransactionStruct`** validation so listed transactions can use the
new type.
> 
> Adds an optional **`details.typeLabel`** string on
**`TransactionDetailsStruct`** for custom UI copy (e.g. “Revoke USDC
approval”) without changing the canonical `type`. Tests cover
valid/invalid `typeLabel` and combined `details` fields; the changelog
documents both additions.
> 
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
98aaf02. Bugbot is set up for automated
code reviews on this repo. Configure
[here](https://www.cursor.com/dashboard/bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: stanleyyconsensys

packages/keyring-api/CHANGELOG.md

@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Add `TransactionType.TokenDisapprove` for token disapproval transactions ([#568](https://github.com/MetaMask/accounts/pull/568))
+- Add optional `TransactionDetails.typeLabel` ([#568](https://github.com/MetaMask/accounts/pull/568))
+  - This can be used to display a custom label regarding the transaction type.
+
 ## [23.2.0]
 
 ### Added

packages/keyring-api/src/api/transaction.test.ts

@@ -46,6 +46,26 @@ describe('TransactionStruct', () => {
         },
         expected: true,
       },
+      // With typeLabel
+      {
+        transaction: {
+          ...baseTransaction,
+          details: { typeLabel: 'Revoke USDC approval' },
+        },
+        expected: true,
+      },
+      // With all details fields
+      {
+        transaction: {
+          ...baseTransaction,
+          details: {
+            origin: 'metamask',
+            securityAlertResponse: 'Benign',
+            typeLabel: 'Some label',
+          },
+        },
+        expected: true,
+      },
       // All valid securityAlertResponse values
       {
         transaction: {
@@ -76,6 +96,14 @@ describe('TransactionStruct', () => {
         },
         expected: false,
       },
+      // Invalid typeLabel
+      {
+        transaction: {
+          ...baseTransaction,
+          details: { typeLabel: 123 },
+        },
+        expected: false,
+      },
     ])(
       'returns $expected for is($transaction, TransactionStruct)',
       ({ transaction, expected }) => {

packages/keyring-api/src/api/transaction.ts

@@ -170,6 +170,11 @@ export enum TransactionType {
    */
   TokenApprove = 'token:approve',
 
+  /**
+   * Represents a token disapproval transaction.
+   */
+  TokenDisapprove = 'token:disapprove',
+
   /**
    * The transaction type is unknown. It's not possible to determine the
    * transaction type based on the information available.
@@ -215,6 +220,13 @@ export enum SecurityAlertResponse {
  *   securityAlertResponse: 'Warning',
  * }
  * ```
+ *
+ * @example
+ * ```ts
+ * {
+ *   typeLabel: 'Some label',
+ * }
+ * ```
  */
 export const TransactionDetailsStruct = object({
   /**
@@ -236,6 +248,11 @@ export const TransactionDetailsStruct = object({
       `${SecurityAlertResponse.Malicious}`,
     ]),
   ),
+
+  /**
+   * Optional transaction type label (for UI display purposes).
+   */
+  typeLabel: exactOptional(string()),
 });
 
 /**
@@ -361,6 +378,7 @@ export const TransactionStruct = object({
     `${TransactionType.StakeDeposit}`,
     `${TransactionType.StakeWithdraw}`,
     `${TransactionType.TokenApprove}`,
+    `${TransactionType.TokenDisapprove}`,
     `${TransactionType.Unknown}`,
   ]),
 
@@ -390,9 +408,9 @@ export const TransactionStruct = object({
   /**
    * Additional transaction details {@see TransactionDetailsStruct}.
    *
-   * Contains contextual information about the transaction such as its origin and
-   * security assessment. This field is optional and may not be present for all
-   * transactions.
+   * Contains contextual information about the transaction such as its origin,
+   * security assessment, and optional `typeLabel`. This field is optional and
+   * may not be present for all transactions.
    */
   details: exactOptional(TransactionDetailsStruct),
 });