feat(Conditionals): Add IfNot

BHC-IT · Jun 1, 2023 · 8988ca7 · 8988ca7
1 parent 3b8dd94
commit 8988ca7
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Showing 2 changed files with 16 additions and 1 deletion.
diff --git a/tests/Conditionals.test.d.ts b/tests/Conditionals.test.d.ts
@@ -12,6 +12,7 @@ import {
   IsNever,
   IfNever,
   MutuallyExtend,
+  IfNot,
 } from '../types'
 
 type __TEST__ = {
@@ -20,6 +21,11 @@ type __TEST__ = {
     ExpectTrue<If<true, true, false>>,
     ExpectFalse<If<false, true, false>>,
   ]
+  // prettier-ignore
+  IfNot: [
+    ExpectTrue<IfNot<false, true, false>>,
+    ExpectFalse<IfNot<true, true, false>>
+  ]
   // If any edge case comes up when this type misbehaves,
   // add it here before editing the type.
   Extends: [

diff --git a/types/Conditionals.d.ts b/types/Conditionals.d.ts
@@ -2,7 +2,16 @@ import { ExpectExtends, IsAny, NotAny as IsNotAny } from '@type-challenges/utils
 
 export { IsAny, IsNotAny, ExpectExtends }
 
-export type If<Test extends boolean, OnTrue, OnFalse = never> = Test extends true ? OnTrue : OnFalse
+// prettier-ignore
+export type If<Test extends boolean, OnTrue, OnFalse = never>
+  = Test extends true
+    ? OnTrue
+    : OnFalse
+// prettier-ignore
+export type IfNot<Test extends boolean, OnFalse, OnTrue = never>
+  = Test extends false
+    ? OnFalse
+    : OnTrue
 
 // prettier-ignore
 export type Extends<Type, ToExtend>