30 lines
900 B
TypeScript
30 lines
900 B
TypeScript
// https://github.com/Microsoft/TypeScript/issues/29006
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export interface A { type: 'a' }
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export interface B { type: 'b' }
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export type AB = A | B
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const itemId = 'some-id'
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// --- test on first level ---
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const items: { [id: string]: AB } = {}
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const { [itemId]: itemOk1 } = items
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typeof itemOk1 // pass
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// --- test on second level ---
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interface ObjWithItems {
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items: {[s: string]: AB}
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}
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const objWithItems: ObjWithItems = { items: {}}
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const itemOk2 = objWithItems.items[itemId]
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typeof itemOk2 // pass
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const {
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items: { [itemId]: itemWithTSError } = {} /*happens when default value is provided*/
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} = objWithItems
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// in order to re-produce the error, uncomment next line:
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typeof itemWithTSError // :(
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// will result in:
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// Error from compilation: TypeError: Cannot read property 'charCodeAt' of undefined TypeError: Cannot read property 'charCodeAt' of undefined
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