[No QA] Clean up unsafe type assertions in unit tests

[KJ21-ENG]

Explanation of Change

This test-only cleanup removes 172 @typescript-eslint/no-unsafe-type-assertion findings from the ten authorized unit-test files. It replaces unsafe assertions with production-derived types, typed mocks and fixtures, and narrow type-safe handling for intentional malformed runtime fixtures while preserving the existing test scenarios and runtime behavior.

Fixed Issues

$ #94739
PROPOSAL: #94739 (comment)

Count change

Current baseline source:

• The tracked config/eslint/eslint.seatbelt.tsv at base 2c95456c78d65e54730dcde1f758292472ab59fa records the baseline for @typescript-eslint/no-unsafe-type-assertion.

Before:

• tests/unit/BankAccountUtilsTest.ts: 16 findings
• tests/unit/ImportTransactions.test.ts: 16 findings
• tests/unit/ReportUtilsTest.ts: 19 findings
• tests/unit/TransactionUtilsTest.ts: 20 findings
• tests/unit/ViolationUtilsTest.ts: 20 findings
• tests/unit/hooks/useAssignCard.test.ts: 16 findings
• tests/unit/hooks/useFilterFormValues.test.ts: 15 findings
• tests/unit/hooks/useSearchBulkActionsDuplicateTest.ts: 19 findings
• tests/unit/libs/SplitExpenseUtils.test.ts: 15 findings
• tests/unit/useAccountIndicatorChecksTest.ts: 16 findings

After:

• tests/unit/BankAccountUtilsTest.ts: 0 findings
• tests/unit/ImportTransactions.test.ts: 0 findings
• tests/unit/ReportUtilsTest.ts: 0 findings
• tests/unit/TransactionUtilsTest.ts: 0 findings
• tests/unit/ViolationUtilsTest.ts: 0 findings
• tests/unit/hooks/useAssignCard.test.ts: 0 findings
• tests/unit/hooks/useFilterFormValues.test.ts: 0 findings
• tests/unit/hooks/useSearchBulkActionsDuplicateTest.ts: 0 findings
• tests/unit/libs/SplitExpenseUtils.test.ts: 0 findings
• tests/unit/useAccountIndicatorChecksTest.ts: 0 findings

Net reduction:

• 172 fewer @typescript-eslint/no-unsafe-type-assertion findings across the ten target files.

TSV evidence:

• The exact base TSV rows above provide the 172-finding baseline. Complete cleanup-count verification at exact head 78c65d10d9a14eecc2aff2dbb488b7071bce4e51 reported zero remaining findings for every target, and the tracked TSV was restored unchanged.

Tests

1. The deterministic complete verification packet passed cleanup counting, focused formatting, focused lint, focused Jest through the worktree-aware resolver, and git diff --check for all ten targets.
2. Fork CI run 30467957722 passed typecheck, lint, format, React Compiler, and Jest for exact head 78c65d10d9a14eecc2aff2dbb488b7071bce4e51.
3. Focused typecheck is not run locally because no bounded project typecheck is available for these test files; Fork CI is authoritative for that check.
4. No manual platform testing was performed; the evidence is automated verification only.

Offline tests

N/A — this is a test-only type-safety cleanup; it changes no application runtime or network behavior, and no manual offline test was performed.

QA Steps

N/A — this is a test-only cleanup and the title starts with [No QA]; no staging or production manual QA was performed.

PR Author Checklist

Checklist note: every item below is checked to record that it was considered. Platform, staging or production, offline, screenshot or video, high-traffic, console, and product-component testing are N/A for this test-only cleanup; no manual platform or product testing is claimed. The automated evidence is listed in ### Tests.

• I linked the correct issue in the ### Fixed Issues section above
• I wrote clear testing steps that cover the changes made in this PR
  • I added steps for local testing in the Tests section
  • I added steps for the expected offline behavior in the Offline steps section
  • I added steps for Staging and/or Production testing in the QA steps section
  • I added steps to cover failure scenarios (i.e. verify an input displays the correct error message if the entered data is not correct)
  • I turned off my network connection and tested it while offline to ensure it matches the expected behavior (i.e. verify the default avatar icon is displayed if app is offline)
  • I tested this PR with a High Traffic account against the staging or production API to ensure there are no regressions (e.g. long loading states that impact usability).
• I included screenshots or videos for tests on all platforms
• I ran the tests on all platforms & verified they passed on:
  • Android: Native
  • Android: mWeb Chrome
  • iOS: Native
  • iOS: mWeb Safari
  • MacOS: Chrome / Safari
• I verified there are no console errors (if there's a console error not related to the PR, report it or open an issue for it to be fixed)
• I followed proper code patterns (see Reviewing the code)
  • I verified that comments were added to code that is not self explanatory
  • I verified that any new or modified comments were clear, correct English, and explained "why" the code was doing something instead of only explaining "what" the code was doing.
  • I verified any copy / text that was added to the app is grammatically correct in English. It adheres to proper capitalization guidelines (note: only the first word of header/labels should be capitalized), and is either coming verbatim from figma or has been approved by marketing (in order to get marketing approval, ask the Bug Zero team member to add the Waiting for copy label to the issue)
• If a new code pattern is added I verified it was agreed to be used by multiple Expensify engineers
• I followed the guidelines as stated in the Review Guidelines
• I tested other components that can be impacted by my changes (i.e. if the PR modifies a shared library or component like Avatar, I verified the components using Avatar are working as expected)
• If a new CSS style is added I verified that:
  • A similar style doesn't already exist
  • The style can't be created with an existing StyleUtils function (i.e. StyleUtils.getBackgroundAndBorderStyle(theme.componentBG))
• If new assets were added or existing ones were modified, I verified that:
  • The assets are optimized and compressed (for SVG files, run npm run compress-svg)
  • The assets load correctly across all supported platforms.
• If the PR modifies code that runs when editing or sending messages, I tested and verified there is no unexpected behavior for all supported markdown - URLs, single line code, code blocks, quotes, headings, bold, strikethrough, and italic.
• If the PR modifies a generic component, I tested and verified that those changes do not break usages of that component in the rest of the App (i.e. if a shared library or component like Avatar is modified, I verified that Avatar is working as expected in all cases)
• If the PR modifies a component related to any of the existing Storybook stories, I tested and verified all stories for that component are still working as expected.
• If the PR modifies a component or page that can be accessed by a direct deeplink, I verified that the code functions as expected when the deeplink is used - from a logged in and logged out account.
• If the PR modifies the UI (e.g. new buttons, new UI components, changing the padding/spacing/sizing, moving components, etc) or modifies the form input styles:
  • I verified that all the inputs inside a form are aligned with each other.
  • I added Design label and/or tagged @Expensify/design so the design team can review the changes.
• I added unit tests for any new feature or bug fix in this PR to help automatically prevent regressions in this user flow.
• If the main branch was merged into this PR after a review, I tested again and verified the outcome was still expected according to the Test steps.

Screenshots/Videos

N/A — no UI changes; no screenshots or videos were produced.

Changed files (10)

• tests/unit/BankAccountUtilsTest.ts
• tests/unit/ImportTransactions.test.ts
• tests/unit/ReportUtilsTest.ts
• tests/unit/TransactionUtilsTest.ts
• tests/unit/ViolationUtilsTest.ts
• tests/unit/hooks/useAssignCard.test.ts
• tests/unit/hooks/useFilterFormValues.test.ts
• tests/unit/hooks/useSearchBulkActionsDuplicateTest.ts
• tests/unit/libs/SplitExpenseUtils.test.ts
• tests/unit/useAccountIndicatorChecksTest.ts