feat(Test): Add ExpectEmpty<T extends Traversable>

BHC-IT · May 30, 2023 · 121c21e · 121c21e
1 parent 77da038
commit 121c21e
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Showing 2 changed files with 9 additions and 1 deletion.
diff --git a/tests/Test.test.d.ts b/tests/Test.test.d.ts
@@ -1,4 +1,4 @@
-import { ExpectTrue, ExpectNever, ExpectFalse, ExpectNotNever, ExpectEqual } from '../types'
+import { ExpectTrue, ExpectNever, ExpectFalse, ExpectNotNever, ExpectEqual, ExpectEmpty } from '../types'
 
 declare namespace ExpectTrue {
   export type TwentyThree = 23
@@ -44,4 +44,9 @@ type __TEST__ = {
     ExpectTrue<ExpectNotNever<'literal'>>,
     ExpectTrue<ExpectNotNever<23>>
   ]
+  // prettier-ignore
+  ExpectEmpty: [
+    ExpectTrue<ExpectEmpty<[]>>,
+    ExpectFalse<ExpectEmpty<['wesh']>>
+  ]
 }
diff --git a/types/Test.d.ts b/types/Test.d.ts
@@ -1,6 +1,7 @@
 // @ts-nocheck These types cause TS errors when not used in a testing context
 
 import { Expect, ExpectTrue, ExpectFalse, ExpectExtends, ExpectValidArgs, Equal, NotEqual } from '@type-challenges/utils'
+import { EmptyArray, Traversable } from './ArrayUtils'
 import { IsNever } from './Conditionals'
 
 export { Expect, ExpectTrue, ExpectFalse, ExpectExtends, ExpectValidArgs, Equal, NotEqual }
@@ -12,3 +13,5 @@ export type ExpectEqual<T, U> = Expect<Equal<T, U>>
 export type ExpectNotEqual<T, U> = Not<ExpectEqual<T, U>>
 
 export type ExpectNotExtends<T, U> = Not<ExpectExtends<T, U>>
+
+export type ExpectEmpty<T extends Traversable> = Expect<Equal<T, EmptyArray>>