test: improves mocks to allow plain text reponses

[christopherferreira9]

Description

• Fix geolocation mock to return plain text (us-ca) instead of a JSON object, matching the real API's response format. The app reads this with response.text(), so a JSON object gets stringified and can produce malformed URLs when used in path segments.
• Support string responses in the mock server layer — both MockServerE2E.ts and mockHelpers.ts now return string responses as raw text instead of JSON-serializing them.
• Add catch-all mock for the legacy /regions/{region}/tokens endpoint to DEFAULT_RAMPS_API_MOCKS, preventing unmocked live API calls.
• On mUSD convert disables the synchronization only after tapping the CTA to make sure it is displayed before on a first time user.

This PR addresses a gigantic mocking error on default mocks, specifically speaking the onramp geolocation. This issue was causing random flakiness due to a bad formatted url coming from a mock.
Example: https://on-ramp-cache.uat-api.cx.metamask.io/regions/%7B%22id%22:%22/regions/us-ca%22,%22name%22:%22california%22,%22emoji%22:%22%F0%9F%87%BA%F0%9F%87%B8%22,%22detected%22:true%7D/tokens?action=deposit&sdk=2.1.5 (see run reference)

The reason for this is that the request for https://on-ramp.<ENV>-api.cx.metamask.io/geolocation was returning

{
    id: region.id,
    name: region.name,
    emoji: region.emoji,
    detected: true,
}

when in reality the geolocation endpoint returns plaintext containing the country code for the user's location. This PR adds the ability to the mock server to accept plain text instead of json as a response and fixes the mocking.

It then caused perps tests to fail due to region not available since the fallback country (US) is currently being blacklisted and this was the country used in the onramps default geolocation mock.

CI changes

ref was removed from the shard runner checkout as this was causing inconsistencies with the way every single workflow uses checkout. Builds do not contain a ref which results in building apps with a merge commit instead of the branch commit while tests would run with a different ref resulting in failed tests for changes that were already fixed on main.

Changelog

CHANGELOG entry:

Related issues

Fixes:

Manual testing steps

Feature: my feature name

  Scenario: user [verb for user action]
    Given [describe expected initial app state]

    When user [verb for user action]
    Then [describe expected outcome]

Screenshots/Recordings

Before

After

Pre-merge author checklist

• I've followed MetaMask Contributor Docs and MetaMask Mobile Coding Standards.
• I've completed the PR template to the best of my ability
• I've included tests if applicable
• I've documented my code using JSDoc format if applicable
• I've applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

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.

---

Note

Medium Risk
Moderate risk: changes test infrastructure by installing a lifecycle-wide unhandledRejection filter and altering mock server shutdown behavior, which could mask unexpected promise rejections if the filter is too broad. Functional app code is untouched; impact is limited to E2E reliability and mocking fidelity.

Overview
Fixes onramp geolocation mocking to return plain text region codes (matching the real API) and updates the mocking layer (MockServerE2E, setupMockRequest) to return raw string bodies without JSON-serializing; adds a catch-all mock for legacy /regions/{region}/tokens to prevent live calls.

Hardens E2E infra by adding MockServerE2E.startDraining() (return 503 during cleanup) and installing a lifecycle-wide filter that suppresses mockttp Error('Aborted') unhandled rejections, with cleanup integrated into withFixtures.

Stabilizes flaky Detox flows: waits for elements to stop moving before taps (wallet token rows, confirm button), relaxes a swap analytics assertion to min length, adjusts unified-buy analytics region assertions to expect a string, adds perps geolocation mocking (non-blocked region), and tweaks/simplifies a few smoke tests (mUSD sync timing, SOL send assertions).

^{Written by Cursor Bugbot for commit 27fc622. This will update automatically on new commits. Configure here.}

[github-actions]

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.

[github-actions]

🔍 Smart E2E Test Selection

⏭️ Smart E2E selection skipped - skip-smart-e2e-selection label found

All E2E tests pre-selected.

View GitHub Actions results

[cursor]

Cursor Bugbot has reviewed your changes and found 2 potential issues.

^{Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, have a team admin enable autofix in the Cursor dashboard.}

[Cal-L]

LGTM