fix(types): support branded primitives in evaluate arguments

[dgozman]

Summary

• NoHandles/Unboxed recurse into function return types instead of rewriting every function in the argument, so handle-free values — including branded primitives like string & { __brand } — pass through unchanged, while callbacks returning handles still get their results unboxed
• Promises are only unwrapped in the function result position, matching the runtime behavior

Fixes #42000

[github-actions]

Test results for "tests 1"

1 failed
❌ [playwright-test] › playwright.trace.spec.ts:1267 › should not nest top level expect into unfinished api calls @ubuntu-latest-node24

2 flaky

⚠️ [chromium-library] › library/beforeunload.spec.ts:130 › should support dismissing the dialog multiple times `@chromium-ubuntu-22.04-node22`
⚠️ [firefox-page] › page/page-event-request.spec.ts:181 › should return response body when Cross-Origin-Opener-Policy is set `@firefox-ubuntu-22.04-node20`

50736 passed, 1190 skipped

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Merge workflow run.

[github-actions]

Test results for "MCP"

2 failed
❌ [chrome] › mcp/cli-core.spec.ts:364 › --raw on command without output @mcp-windows-latest-chrome
❌ [firefox] › mcp/cli-core.spec.ts:57 › click link @mcp-windows-latest-firefox

7806 passed, 1266 skipped

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Merge workflow run.

[github-actions]

🟡 Nothing here points at this PR, but one failure I can't fully clear

Hi, I'm the Playwright bot and I took a first look at the CI failures.

This PR only touches TypeScript declarations (packages/playwright-core/types/structs.d.ts) and a type-generation test (utils/generate_types/test/test.ts) — no runtime code. Two of the three failures are proven pre-existing flakes; the third I can't reach with the diff, but I couldn't find a prior failure to call it a flake outright.

Details

Overall: the diff is types-only, so it can't change the runtime behavior of any of these tests. None look caused by this PR.

Pre-existing flake / infra

• [chrome] › mcp/cli-core.spec.ts:364 › --raw on command without output (@mcp-windows-latest-chrome) — flake. Across the test-results DB this test failed 1 of 501 runs, passed the other 500, on SHAs unrelated to this PR.
• [firefox] › mcp/cli-core.spec.ts:57 › click link (@mcp-windows-latest-firefox) — flake. Failed 6 of 486 runs, passed 480, on unrelated SHAs.

Uncertain

• [playwright-test] › playwright.trace.spec.ts:1267 › should not nest top level expect into unfinished api calls (@ubuntu-latest-node24) — this test has passed 681 of 681 recorded runs and failed only here, so I can't cite a prior failure to prove it's a flake (this PR's run isn't in the aggregated DB yet). But the diff only edits .d.ts and type-gen test files, which have zero effect on the trace runtime this test exercises, so I don't see how the PR could cause it. A single un-retried failure on a rock-solid test — most likely a one-off; a rerun should confirm.

_{Triaged by the Playwright bot - agent run}

[github-actions]

Hi, I'm the Playwright bot and I took a first look at the CI failures here.

🟢 CI is clear — all three failures are pre-existing flakes

This PR only touches type declarations (structs.d.ts) and a generate_types test. None of the failing tests exercise the type system — they're a trace-viewer test and two MCP CLI tests — and every one of them fails on other SHAs/PRs too.

Details

Pre-existing flake / infra

• [playwright-test] › playwright.trace.spec.ts:1267 › should not nest top level expect into unfinished api calls — also failed on PR Revert "feat(getByRole): add support for aria-busy (#41269)" #41795 (sha 70b1b43d5c), unrelated to this change. Flakes 2 of ~3159 runs across 183 PRs.
• [chrome] › mcp/cli-core.spec.ts:364 › --raw on command without output — the same test also failed on two push runs (shas e0e867011c, 1299d0f6c4) with no PR attached, so this PR can't be the cause. Flakes 3 of ~5247 runs.
• [firefox] › mcp/cli-core.spec.ts:57 › click link — a well-known flake: failed on PRs fix(aria): preserve names from collapsed text contributors #41988, Revert "chore(deps-dev): bump fast-uri from 3.1.3 to 3.1.4" #41978, fix(mcp): reconnect to the browser after disconnect #41966, chore(recorder): unify action coalescing and simplify action types #41958, feat(firefox): roll to r1538 #41938 and a push run, all without this PR's changes. 7 of ~5247 runs.

The two entries the report already lists as flaky (beforeunload.spec.ts:130, page-event-request.spec.ts:181) passed on retry, so there's nothing to triage there.

I'm a first pass, not the final word — but the type-only diff and the cross-PR failure history both point the same way, so I'm confident this is noise.

_{Triaged by the Playwright bot - agent run}