microsoft / microsoft/tslib

calls to tslib __setFunctionName fail on Cobalt 9

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Dominant language
TypeScript
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Description

We've observed new behavior after upgrading our code to TypeScript 5.0. Specifically, TS5.0 emits calls to a new tslib helper function __setFunctionName. This in turn calls Object.defineProperty(x, "name", ...) on the class, which seems to fail on Cobalt 9:

          TypeError: can't redefine non-configurable property 'name' in [object HTMLScriptElement] (line 76)

We're not sure whether this is an issue with tslib, TS5.0 or with the calling code (in our case I think it's a Jasmine test). I'd be grateful for any guidance the tslib team could provide.

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Research direction

Start by reproducing the TypeScript 5.0-generated call to tslib's __setFunctionName on Cobalt 9 and inspect the reported Object.defineProperty failure. Check whether the failure originates in tslib, TypeScript 5.0, or the Jasmine test case mentioned in the issue. Done means identifying the responsible component and providing guidance or a confirmed compatibility fix.

Written by the indexing model from the issue text.

Assessment

Tech stack
typescript
Domain
tooling
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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