fix: don't materialize a callable leaf's built-in members as child endpoints - #307
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…dpoints The wrapper get trap resolved a property read to `impl[prop]` and, for any function-valued result, wrapped it as a child endpoint and registered ownership. On a callable leaf, that meant merely READING an inherited Function.prototype member — `apply`, `call`, `bind`, `constructor` — (or the non-enumerable own `prototype` slot) rewrote the leaf's loader record: it flipped from kind "function" to "namespace" and grew a phantom child (`leaf.apply`, …). A later leaves() or re-composition then surfaced Function.prototype.apply in place of the leaf. `leaf.apply(thisArg, args)` — a common forwarding idiom — silently corrupted the served surface (Reflect.apply was the only safe workaround). The get trap now returns the function's own built-in members directly instead of wrapping them: for a function impl, a property that is not a user-added ENUMERABLE own property is returned as-is. Genuine enumerable own children of a callable still materialize as endpoints. Covered in eager and lazy modes, including a callable that carries a real user child. Fixes #304
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Pull request overview
This PR fixes a UnifiedWrapper get-trap behavior where reading built-in callable members (e.g. apply/call/bind/constructor/prototype) on a callable leaf could incorrectly materialize them as child endpoints, mutating ownership records (turning a function leaf into a namespace) and creating “phantom” children.
Changes:
- Adds a get-trap guard to return non-enumerable callable members directly instead of wrapping/materializing them as child endpoints.
- Introduces a new Vitest regression suite covering eager and lazy modes, ensuring built-in callable members don’t mutate leaf records while real enumerable children still materialize.
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.
| File | Description |
|---|---|
| src/lib/handlers/unified-wrapper.mjs | Adds a guard in the get trap to avoid wrapping callable built-in members as child endpoints. |
| tests/vitests/suites/unified-wrapper/leaf-function-prototype-read.test.vitest.mjs | Adds regression coverage ensuring Function.prototype member reads don’t create phantom children and don’t mutate leaf kind/records. |
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…port Address Copilot review on #307: add an afterAll that removes the per-run temp fixture dir under tmp/ (it was left behind on every run), and drop the unused `dirname` import.
Shinrai
approved these changes
Aug 24, 2026
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