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'const enum' conflict with 'importsNotUsedAsValue'' #36003
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Also note that the type-only import of the const enum is reported as unused.
I see the motivation, but
import typemeans more than just “don’t emit this import declaration.” It filters the symbol meanings down to just type and type-containing namespace meanings. We’re currently discussing a similar scenario:import type { BaseClass } from './a' declare class C extends BaseClass {} // Should this be treated as having a value?
and the instincts on the team are mixed. But using a type-only import in the right-hand side of an assignment looks really unexpected to me.
If I use a regular import, I get
This import is never used as a value and must use 'import type' because the 'importsNotUsedAsValue' is set to 'error'.ts(1371)This part sounds like a bug
I believe the error
Enum 'E' cannot be used as a value because only its type has been imported.ts(1362)is correct. You must not use a type as a value. And I believe base classes of ambient classes should be treated as having no value because ambient declarations just declare types of existing values.
TypeScript Version: 3.8.0-dev.20200104
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Expected behavior:
No error.
Actual behavior:
Type-only import causes
Enum 'E' cannot be used as a value because only its type has been imported.ts(1362)Since importing const enums at runtime is not necessary due to inlining, they should be allowed to be used with type-only import.
If I use a regular import, I get
This import is never used as a value and must use 'import type' because the 'importsNotUsedAsValue' is set to 'error'.ts(1371)Related Issues: Introduced by Andrew Branch (@andrewbranch) in #35200