[No QA] Reduce unsafe type assertions in TSCompilerUtils tests

[KJ21-ENG]

Explanation of Change

Reduced @typescript-eslint/no-unsafe-type-assertion violations in
tests/unit/TSCompilerUtilsTest.ts as part of the cleanup for Expensify/App
issue #94739.

What changed:

• Replaced repeated TypeScript AST casts in the tests with local typed guard helpers.
• Used TypeScript compiler guards such as ts.isExpressionStatement,
  ts.isPropertyAssignment, and ts.isObjectLiteralExpression.
• Verified with writable lint that the generated target-rule row for this file is removed from the seatbelt TSV.
• The generated TSV diff is intentionally not included in this PR because Expensify/App post-merge OSBotify automation tightens the baseline on main.

Why this approach is safe:

• Test-only change; no product/runtime behavior changed.
• The new helpers fail explicitly if a fixture has a different AST shape.
• Existing fixture strings and assertions were preserved.

Reviewer focus:

1. Start with tests/unit/TSCompilerUtilsTest.ts and confirm the helper checks
   are real AST narrowing rather than hidden unsafe casts.
2. Check the count evidence below and confirm writable lint locally removed the
   TSCompilerUtilsTest.ts target-rule row.
3. Check the commands below; no manual QA is expected for this test-only cleanup.

Safety checks:

• No SEATBELT_INCREASE.
• No new eslint-disable for @typescript-eslint/no-unsafe-type-assertion.
• No broad as unknown as substitutions.
• No generic unsafe helper that hides casts.

Fixed Issues

$ #94739
PROPOSAL:

Count change

Current baseline source:

• config/eslint/eslint.seatbelt.tsv

Before:

• tests/unit/TSCompilerUtilsTest.ts: 96 violations
• Current global target-rule baseline: 5,449 violations

After:

• tests/unit/TSCompilerUtilsTest.ts: 0 violations
• Current global target-rule baseline: 5,353 violations

Net reduction:

• 96 fewer @typescript-eslint/no-unsafe-type-assertion violations.

TSV evidence:

• Writable lint locally removed the tests/unit/TSCompilerUtilsTest.ts row from
  config/eslint/eslint.seatbelt.tsv.
• Generated with:
  CI=true npm run lint -- --no-cache --show-warnings tests/unit/TSCompilerUtilsTest.ts
• The generated config/eslint/eslint.seatbelt.tsv diff is intentionally not
  included in this PR because Expensify/App post-merge OSBotify automation
  tightens the baseline on main.

Tests

1. Run:

   npm run lint -- --show-warnings tests/unit/TSCompilerUtilsTest.ts

   Verify lint passes with no target-rule warnings for the edited file.

2. Run:

   CI=true npm run lint -- --no-cache --show-warnings tests/unit/TSCompilerUtilsTest.ts

   Verify config/eslint/eslint.seatbelt.tsv locally contains the decrement described
   above, then restore it before committing:

   git restore config/eslint/eslint.seatbelt.tsv

3. Run:

   npm run test -- tests/unit/TSCompilerUtilsTest.ts

   Verify the targeted test suite passes.

4. Run:

   npm run typecheck

   Verify TypeScript checks pass.

Offline tests

Not applicable. This is test-only cleanup and does not change network behavior.

QA Steps

No QA required. This PR only changes tests. The ESLint seatbelt baseline is tightened by Expensify/App post-merge OSBotify automation.

PR Author Checklist

For checklist items that are not applicable to this test-only cleanup, checked
means the item was considered and determined not applicable.

• 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 any callback methods that were added or modified are named for what the method does and never what callback they handle (i.e. toggleReport and not onIconClick)
  • 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 any new file was added I verified that:
  • The file has a description of what it does and/or why is needed at the top of the file if the code is not self explanatory
• 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

Android: Native

Not applicable. This is test-only cleanup.

Android: mWeb Chrome

Not applicable. This is test-only cleanup.

iOS: Native

Not applicable. This is test-only cleanup.

iOS: mWeb Safari

Not applicable. This is test-only cleanup.

MacOS: Chrome / Safari

Not applicable. This is test-only cleanup.

cc @blimpich

[melvin-bot]

@jayeshmangwani Please copy/paste the Reviewer Checklist from here into a new comment on this PR and complete it. If you have the K2 extension, you can simply click: [this button]

[roryabraham]

It is not necessary to manually tighten the seatbelt. Entries will be removed from this file on merge. I recommend that you avoid doing it manually before merge to avoid merge conflicts.

The only time you should need to touch this file is when you're adding new exceptions (or renaming a file which contained existing exceptions).

[jayeshmangwani]

@blimpich, tagging you here since you're assigned to the issue.

I'm not sure whether this PR needs a C+ review, since its No QA and only test update.

[KJ21-ENG]

@jayeshmangwani Yes, I have tagged @blimpich on the issue thread. There will likely be no need for a C+ review now. As there will be serise of PRs under #94739 and we might not need a C+ review now but may be on later stage PRs where Prod files will be modfied for cleanup.

[blimpich]

Reviewer Checklist

• I have verified the author checklist is complete (all boxes are checked off).
• I verified the correct issue is linked in the ### Fixed Issues section above
• I verified testing steps are clear and they cover the changes made in this PR
  • I verified the steps for local testing are in the Tests section
  • I verified the steps for Staging and/or Production testing are in the QA steps section
  • I verified the steps cover any possible 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 checked that screenshots or videos are included for tests on all platforms
• I included screenshots or videos for tests on all platforms
• I verified that the composer does not automatically focus or open the keyboard on mobile unless explicitly intended. This includes checking that returning the app from the background does not unexpectedly open the keyboard.
• I verified tests pass on all platforms & I tested again on:
  • Android: HybridApp
  • Android: mWeb Chrome
  • iOS: HybridApp
  • iOS: mWeb Safari
  • MacOS: Chrome / Safari
• If there are any errors in the console that are unrelated to this PR, I either fixed them (preferred) or linked to where I reported them in Slack
• I verified proper code patterns were followed (see Reviewing the code)
  • I verified that any callback methods that were added or modified are named for what the method does and never what callback they handle (i.e. toggleReport and not onIconClick).
  • 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 verified that this PR follows the guidelines as stated in the Review Guidelines
• I verified other components that can be impacted by these changes have been tested, and I retested again (i.e. if the PR modifies a shared library or component like Avatar, I verified the components using Avatar have been tested & I retested again)
• If a new component is created I verified that:
  • A similar component doesn't exist in the codebase
  • All props are defined accurately and each prop has a /** comment above it */
  • The file is named correctly
  • The component has a clear name that is non-ambiguous and the purpose of the component can be inferred from the name alone
  • The only data being stored in the state is data necessary for rendering and nothing else
  • For Class Components, any internal methods passed to components event handlers are bound to this properly so there are no scoping issues (i.e. for onClick={this.submit} the method this.submit should be bound to this in the constructor)
  • Any internal methods bound to this are necessary to be bound (i.e. avoid this.submit = this.submit.bind(this); if this.submit is never passed to a component event handler like onClick)
  • All JSX used for rendering exists in the render method
  • The component has the minimum amount of code necessary for its purpose, and it is broken down into smaller components in order to separate concerns and functions
• If any new file was added I verified that:
  • The file has a description of what it does and/or why is needed at the top of the file if the code is not self explanatory
• 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 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.
• For any bug fix or new feature in this PR, I verified that sufficient unit tests are included to prevent regressions in this 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.
• I have checked off every checkbox in the PR reviewer checklist, including those that don't apply to this PR.

Screenshots/Videos

Android: HybridApp

Android: mWeb Chrome

iOS: HybridApp

iOS: mWeb Safari

MacOS: Chrome / Safari

[OSBotify]

🚀 Deployed to staging by https://github.com/blimpich in version: 9.4.29-0 🚀

platform	result
🕸 web 🕸	success ✅
🤖 android 🤖	success ✅
🍎 iOS 🍎	success ✅

[OSBotify]

🚀 Deployed to staging by https://github.com/blimpich in version: 9.4.31-0 🚀

platform	result
🕸 web 🕸	success ✅
🤖 android 🤖	success ✅
🍎 iOS 🍎	success ✅

[OSBotify]

🚀 Deployed to production by https://github.com/grgia in version: 9.4.31-0 🚀

platform	result
🕸 web 🕸	success ✅
🤖 android 🤖	success ✅
🍎 iOS 🍎	success ✅

Bundle Size Analysis (Sentry):

• Android