Compilation error using conditional types + property decorators #27999
Description
TypeScript Version: 3.1.3 and 3.2.0-dev.20181019
Search Terms: Debug Failure. Unexpected node. Node 173 was unexpected.
Code
function Column(): PropertyDecorator {
return () => undefined;
}
export abstract class BaseEntity<T> {
@Column()
public attributes: T extends { attributes: infer A } ? A : undefined;
}Expected behavior:
The program should successfully compile. Note that the specific implementation of the decorator function does not matter.
Actual behavior:
Error: Debug Failure. Unexpected node.
Node 173 was unexpected.
at serializeTypeNode (/opt/app/node_modules/typescript/lib/tsc.js:54893:37)
at serializeTypeOfNode (/opt/app/node_modules/typescript/lib/tsc.js:54779:28)
at addOldTypeMetadata (/opt/app/node_modules/typescript/lib/tsc.js:54721:92)
at addTypeMetadata (/opt/app/node_modules/typescript/lib/tsc.js:54715:17)
at transformAllDecoratorsOfDeclaration (/opt/app/node_modules/typescript/lib/tsc.js:54634:13)
at generateClassElementDecorationExpression (/opt/app/node_modules/typescript/lib/tsc.js:54659:40)
at generateClassElementDecorationExpressions (/opt/app/node_modules/typescript/lib/tsc.js:54645:34)
at addClassElementDecorationStatements (/opt/app/node_modules/typescript/lib/tsc.js:54638:44)
at visitClassDeclaration (/opt/app/node_modules/typescript/lib/tsc.js:54314:13)
at visitTypeScript (/opt/app/node_modules/typescript/lib/tsc.js:54206:28)