feat(typescript-types): Add If<Test,TrueBranch,FalseBranch>

packages/typescript-types/src/if.ts

@@ -0,0 +1,13 @@
+import type { IsAny } from './is-any.js'
+import type { IsNever } from './is-never.js'
+
+// Note: Returns a union of TrueBranch and FalseBranch if Test is any or boolean
+// Note: Returns FalseBranch if Test is never
+export type If<Test, TrueBranch, FalseBranch> =
+	IsAny<Test> extends true
+		? FalseBranch
+		: IsNever<Test> extends true
+			? FalseBranch
+			: Test extends true
+				? TrueBranch
+				: FalseBranch