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Cannot find name and using private name when export a type. #22220
Description
typescript: 2.7.2
vscode: 1.20.1
tsconfig:
{
"compilerOptions": {
"target": "es5",
"module": "es2015",
"lib": ["es2015", "es2015.core", "dom"],
"jsx": "react",
"declaration": true,
"removeComments": true,
"noUnusedLocals": true,
"noUnusedParameters": true,
"moduleResolution": "node",
"typeRoots": ["./typings", "./node_module/@types"],
"types": ["modules", "node", "dom-align", "css-animation"],
"allowSyntheticDefaultImports": true
}
}
export type OneOf<T extends any[]> = T[number];
export const placements: string[] = [
'top',
'left',
'right',
'bottom',
'topLeft',
'topRight',
'bottomLeft',
'bottomRight',
'leftTop',
'leftBottom',
'rightTop',
'rightBottom',
];
export type Placement = OneOf<placements>;
Expected behavior: It should work well.
Actual behavior: Throw errors that cannot find name and using private name.
But if I replace the generic placements to the primitive array, it would works.
export type OneOf<T extends any[]> = T[number];
export const placements: string[] = [
'top',
'left',
'right',
'bottom',
'topLeft',
'topRight',
'bottomLeft',
'bottomRight',
'leftTop',
'leftBottom',
'rightTop',
'rightBottom',
];
export type Placement = OneOf<[
'top',
'left',
'right',
'bottom',
'topLeft',
'topRight',
'bottomLeft',
'bottomRight',
'leftTop',
'leftBottom',
'rightTop',
'rightBottom'
]>;And this code would not cause that errors.
Activity
vincentdchan commentedon Feb 28, 2018
The variable
placementswill not be regarded as a type. It's a value. That's why you can not use generic type such asOneOf.vincentdchan commentedon Feb 28, 2018
In this situation, just use:
sheltondong commentedon Feb 28, 2018
But it is still a value when I using primitive array, why should that works?
This is still a value
typescript-bot commentedon Mar 14, 2018
Automatically closing this issue for housekeeping purposes. The issue labels indicate that it is unactionable at the moment or has already been addressed.