[Copilot]

Calling getSignaturesOfType on a decorator’s contextual type panics when serialization tries to create a node handle for a synthetic declaration without a source file.

• Serialization: Omit source-less signature declarations from API responses while preserving their internal checker representation.
• Regression coverage: Add async and generated sync API tests verifying the call signature, its parameters, and the absent declaration.

• Fixes Panic in getSignaturesOfType on a decorator's contextual type in JS API #64863

[Wesley Wigham (weswigham)]

Copilot this looks more like a workaround - consider where synthetic signature declarations come from in the checker and if they just need to be made a wee bit less synthetic to be serialized by the API

[Copilot]

Copilot this looks more like a workaround - consider where synthetic signature declarations come from in the checker and if they just need to be made a wee bit less synthetic to be s...

Reworked in a6da8d9 and f7d20b6: synthetic call-signature declarations now belong to a shared virtual source-file AST, so the API returns resolvable declarations rather than omitting them. Their positions remain synthesized to preserve checker/node-builder behavior, and the virtual file stays outside program inputs. Async/sync tests cover declaration resolution and checker round-tripping. npx hereby validate --api passes.

[Wesley Wigham (weswigham)]

Interesting.

Andrew Branch (@andrewbranch) how do you feel about this approach?