fix(types): stop advertising isAction on components that cannot honour it

[IgorShevchik]

Linked issue

None — found while re-measuring #88 against upstream.

Type of change

• Documentation (updates to the documentation or readme)
• Bug fix (a non-breaking change that fixes an issue)
• Enhancement (improving an existing functionality)
• New feature (a non-breaking change that adds functionality)
• Chore (updates to the build process or auxiliary tools and libraries)
• Revert (undoing a merged change — retitle this PR revert(Scope): ...)
• Breaking change (fix or feature that would cause existing functionality to change)

⚠️ Shipping as a patch, deliberately — but it can fail a downstream build

Runtime behaviour does not change: isAction never reached anything outside Link, so nothing that worked before stops working. What changes is that TypeScript now rejects isAction where it used to accept it silently. A project passing it to B24Button or to a page/footer/content-search link will fail to compile after upgrading.

That was weighed: a BREAKING CHANGE footer would take the package to a major version for the removal of a prop that never did anything, and a silent patch would hand people a red build with no warning. The middle course is this — fix(types) with the consequence stated plainly here and in the squash body, so it reads as a visible line in the changelog rather than a surprise. The fix is a one-word deletion at the call site.

Description

isAction restyles a link as Bitrix24's dashed "action" text. src/theme/link.ts is the only theme that implements it, and it is deliberately absent from linkKeys — so pickLinkProps never forwards it downstream.

Everything spreading LinkProps inherited it anyway. A consumer could write isAction on a B24Button or a breadcrumb item, TypeScript accepted it, Vue registered it, and nothing changed on screen. Button declared it as a real runtime prop:

before   Object.keys(Button.props).length === 45   // includes 'isAction'
after    Object.keys(Button.props).length === 44

Ten types across nine files omit it now — ButtonProps, BreadcrumbItem, CommandPaletteItem, ContentSearchItem, ContentSearchLink, ContextMenuItem, DropdownMenuItem, FooterColumnLink, NavigationMenuItem, PageLink — and anything extending ButtonProps follows. Link keeps it.

Nothing in the repository passed it anywhere but B24Link, so no example, playground or documentation changes.

What is enforceable, and what is not

The omission does not mean the same thing everywhere, and the spec says so rather than pretending:

type	index signature	omission enforceable
ButtonProps	no	yes
PageLink	no	yes
FooterColumnLink	no	yes
ContentSearchLink	no	yes
BreadcrumbItem, DropdownMenuItem, NavigationMenuItem, ContextMenuItem, CommandPaletteItem, ContentSearchItem	[key: string]: any	no

Those six accept arbitrary attributes by design, so keyof includes string and no Omit can make isAction unassignable on them. Their omission states intent the compiler cannot check. The spec asserts only the four it can — a test that cannot fail is worse than none.

The guard, and why it is in two halves

They fail under different commands, and neither covers the other:

• expect(Object.keys(Button.props)).not.toContain('isAction') and expect(linkKeys).not.toContain('isAction') fail under vitest run.
• The expectTypeOf assertions are erased at runtime; only vue-tsc (pnpm run typecheck) checks them.

Both mutation-checked: reverting Button's omit reddens two tests in vitest run; reverting PageLink's or ContentSearchLink's reddens typecheck.

The type predicate is written out as type HasIsAction<T> = 'isAction' extends keyof T ? true : false rather than using expectTypeOf().not.toHaveProperty(). The latter was tried first and gave results that did not match how it reads on types with an index signature, with error TS2554: Expected 2 arguments, but got 1 as its failure message.

Review

/review caught the first sweep reading only src/runtime/components/*.vue and never descending into content/, leaving ContentSearchLink and ContentSearchItem still advertising the prop. Fixed in the second commit; the sweep is now a search across all of src/, and ContentSearchLink is mutation-checked with the rest.

The five-reviewer panel was not convened: nine one-line type edits and one spec, with both halves already proven by mutation.

Provenance

isAction is ours, not inherited: nuxt/ui@v4 has no such prop anywhere.

Gate

lint, typecheck, 322 test files / 7498 tests, test:module, and coverage 71.89 / 69.93 / 71.19 / 71.44 against thresholds of 70 / 68 / 70 / 70.

Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.