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A community effort to enrich TypeScript diagnostics.

Editing TS1059:

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TS1059

A promise must have a 'then' method.

This is caused by the global Promise not containing a callable then method and therefore not supporting async/await downlevel emit.

Fix: Issue with types.

The most common fix for this is that is the types for the 3rd party promise library is not configured properly. Refer to current documentation for using the 3rd party promise library.