chore: Blockaid remove unfair_trade reason type (#21386)

## **Description**
Blockaid code updates:
- remove unused unfair_trade reason type (see [Internal
Thread](https://consensys.slack.com/archives/C04D224QTLM/p1696953183067779))

## **Manual testing steps**

1. go to test-dapp
2. test PPOM buttons
3. observe no changes

## **Screenshots/Recordings**

## **Related issues**

Fixes MetaMask/MetaMask-planning#1484
Mobile update: MetaMask/metamask-mobile#7505

## **Pre-merge author checklist**

- [ ] I’ve followed [MetaMask Coding
Standards](https://github.com/MetaMask/metamask-extension/blob/develop/.github/guidelines/CODING_GUIDELINES.md).
- [ ] I've clearly explained:
  - [ ] What problem this PR is solving.
  - [ ] How this problem was solved.
  - [ ] How reviewers can test my changes.
- [ ] I’ve indicated what issue this PR is linked to: Fixes #???
- [ ] I’ve included tests if applicable.
- [ ] I’ve documented any added code.
- [ ] I’ve applied the right labels on the PR (see [labeling
guidelines](https://github.com/MetaMask/metamask-extension/blob/develop/.github/guidelines/LABELING_GUIDELINES.md)).
- [ ] I’ve properly set the pull request status:
  - [ ] In case it's not yet "ready for review", I've set it to "draft".
- [ ] In case it's "ready for review", I've changed it from "draft" to
"non-draft".

## **Pre-merge reviewer checklist**

- [ ] I've manually tested the PR (e.g. pull and build branch, run the
app, test code being changed).
- [ ] I confirm that this PR addresses all acceptance criteria described
in the ticket it closes and includes the necessary testing evidence such
as recordings and or screenshots.

shared/constants/security-provider.ts

@@ -43,12 +43,10 @@ export enum BlockaidReason {
   transferFarming = 'transfer_farming',
   /** Direct theft of assets using transferFrom  */
   transferFromFarming = 'transfer_from_farming',
-  /** Malicious trade that results in the victim being drained  */
-  unfairTrade = 'unfair_trade',
 
   other = 'other',
 
-  // Locally defined
+  // MetaMask defined reasons
   failed = 'Failed',
   notApplicable = 'NotApplicable',
 }
@@ -57,7 +55,8 @@ export enum BlockaidResultType {
   Malicious = 'Malicious',
   Warning = 'Warning',
   Benign = 'Benign',
-  // Locally defined
+
+  // MetaMask defined result types
   Failed = 'Failed',
   NotApplicable = 'NotApplicable',
 }

test/e2e/flask/ppom-blockaid-alert.spec.js

@@ -129,7 +129,7 @@ describe('Confirmation Security Alert - Blockaid', function () {
 
   /**
    * Disclaimer: This test does not test all reason types. e.g. 'blur_farming',
-   * 'malicious_domain', 'unfair_trade'. Some other tests are found in other files:
+   * 'malicious_domain'. Some other tests are found in other files:
    * e.g. test/e2e/flask/ppom-blockaid-alert-<name>.spec.js
    */
   it('should show security alerts for malicious requests', async function () {

ui/components/app/security-provider-banner-alert/blockaid-banner-alert/blockaid-banner-alert.js

@@ -32,7 +32,6 @@ const REASON_TO_DESCRIPTION_TKEY = Object.freeze({
 
   [BlockaidReason.rawSignatureFarming]: 'blockaidDescriptionMightLoseAssets',
   [BlockaidReason.tradeOrderFarming]: 'blockaidDescriptionMightLoseAssets',
-  [BlockaidReason.unfairTrade]: 'blockaidDescriptionMightLoseAssets',
 
   [BlockaidReason.rawNativeTokenTransfer]: 'blockaidDescriptionTransferFarming',
   [BlockaidReason.transferFarming]: 'blockaidDescriptionTransferFarming',

ui/components/app/security-provider-banner-alert/blockaid-banner-alert/blockaid-banner-alert.test.js

@@ -170,8 +170,6 @@ describe('Blockaid Banner Alert', () => {
         'If you approve this request, a third party known for scams will take all your assets.',
       [BlockaidReason.transferFarming]:
         'If you approve this request, a third party known for scams will take all your assets.',
-      [BlockaidReason.unfairTrade]:
-        'If you approve this request, you might lose your assets.',
     }).forEach(([reason, expectedDescription]) => {
       it(`should render for '${reason}' correctly`, () => {
         const { getByText } = renderWithLocalization(