feat(utils): tryit

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

src/utils/__tests__/tryit.spec.ts

@@ -0,0 +1,40 @@
+/**
+ * @file Unit Tests - tryit
+ * @module tutils/utils/tests/unit/tryit
+ */
+
+import INTEGER from '#fixtures/integer'
+import type { Fn } from '#src/types'
+import type { Mock } from '#tests/interfaces'
+import testSubject from '../tryit'
+
+describe('unit:utils/tryit', () => {
+  let fn: Mock<Fn<[string?], typeof INTEGER>>
+
+  beforeAll(() => {
+    fn = vi.fn()
+  })
+
+  it('should return error-first async callback', () => {
+    expect(testSubject(fn)).to.be.a('function')
+  })
+
+  describe('error-first callback', () => {
+    it('should return [error, null] if fn throws', async () => {
+      // Arrange
+      const error: Error = new Error('not implemented')
+      fn.mockRejectedValueOnce(error)
+
+      // Act + Expect
+      expect(await testSubject(fn)()).to.deep.equal([error, null])
+    })
+
+    it('should return [null, result]', async () => {
+      // Arrange
+      fn.mockResolvedValueOnce(INTEGER)
+
+      // Act + Expect
+      expect(await testSubject(fn)()).to.deep.equal([null, INTEGER])
+    })
+  })
+})

src/utils/index.ts

@@ -57,5 +57,6 @@ export { default as timeunix } from './timeunix'
 export { default as trim } from './trim'
 export { default as trimEnd } from './trim-end'
 export { default as trimStart } from './trim-start'
+export { default as tryit } from './tryit'
 export { default as unique } from './unique'
 export { default as uppercase } from './uppercase'

src/utils/tryit.ts

@@ -0,0 +1,29 @@
+/**
+ * @file Utilities - tryit
+ * @module tutils/utils/tryit
+ */
+
+import type { Fn, Tryit } from '#src/types'
+
+/**
+ * Converts `fn` to an error-first callback.
+ *
+ * @template T - Function to convert
+ * @template E - Error type
+ *
+ * @param {T} fn - Function to convert
+ * @return {Tryit<T, E>} Error first callback
+ */
+function tryit<T extends Fn, E extends Error = Error>(fn: T): Tryit<T, E> {
+  return async (
+    ...args: Parameters<T>
+  ): Promise<[E, null] | [null, Awaited<ReturnType<T>>]> => {
+    try {
+      return [null, (await fn(...args)) as Awaited<ReturnType<T>>]
+    } catch (e: unknown) {
+      return [e as E, null]
+    }
+  }
+}
+
+export default tryit