feat(types): IfTuple

Signed-off-by: Lexus Drumgold <[email protected]>

src/types/__tests__/if-tuple.spec-d.ts

@@ -0,0 +1,19 @@
+/**
+ * @file Type Tests - IfTuple
+ * @module tutils/types/tests/unit-d/IfTuple
+ */
+
+import type TestSubject from '../if-tuple'
+
+describe('unit-d:types/IfTuple', () => {
+  type False = false
+  type True = true
+
+  it('should equal False if IsTuple<T> extends false', () => {
+    expectTypeOf<TestSubject<number[], True, False>>().toEqualTypeOf<False>()
+  })
+
+  it('should equal True if IsTuple<T> extends true', () => {
+    expectTypeOf<TestSubject<[0, 1, 2], True, False>>().toEqualTypeOf<True>()
+  })
+})

src/types/if-tuple.ts

@@ -0,0 +1,22 @@
+/**
+ * @file Type Definitions - IfTuple
+ * @module tutils/types/IfTuple
+ */
+
+import type IsTuple from './is-tuple'
+
+/**
+ * Conditional type that resolves depending on whether or not `T` is a
+ * [tuple][1] type.
+ *
+ * [1]: https://www.codecademy.com/resources/docs/typescript/tuples
+ *
+ * @see {@linkcode IsTuple}
+ *
+ * @template T - Type to evaluate
+ * @template True - Type if `T` is tuple type
+ * @template False - Type if `T` is not tuple type
+ */
+type IfTuple<T, True, False> = IsTuple<T> extends true ? True : False
+
+export type { IfTuple as default }

src/types/index.ts

@@ -36,6 +36,7 @@ export type { default as IfNumeric } from './if-numeric'
 export type { default as IfPrimitive } from './if-primitive'
 export type { default as IfString } from './if-string'
 export type { default as IfSymbol } from './if-symbol'
+export type { default as IfTuple } from './if-tuple'
 export type { default as IndexSignature } from './index-signature'
 export type { default as IsAny } from './is-any'
 export type { default as IsArray } from './is-array'