Implement asyncPipe

src/Helpers/async-pipe.test.ts

@@ -0,0 +1,34 @@
+import { identity } from 'ramda'
+import { describe } from 'riteway'
+import { asyncPipe } from './async-pipe'
+import { toPromise } from './to-promise'
+
+const double = (x: number) => x * 2
+const inc = (x: number) => x + 1
+
+const doubleP = toPromise(double)
+const incP = toPromise(inc)
+
+describe('asyncPipe', async (assert: any) => {
+  const should = 'apply the value to the functions composition correctly'
+
+  {
+    const value = 10
+    assert({
+      given: 'sync and async functions',
+      should,
+      actual: await asyncPipe(doubleP, inc)(value).catch(identity),
+      expected: inc(await doubleP(value)),
+    })
+  }
+
+  {
+    const value = 10
+    assert({
+      given: 'nested compositions of sync and async functions',
+      should,
+      actual: await asyncPipe(doubleP, inc, asyncPipe(double, incP))(value).catch(identity),
+      expected: await incP(double(inc(await doubleP(value)))),
+    })
+  }
+})

src/Helpers/async-pipe.ts

@@ -0,0 +1,4 @@
+type Func = (v?: any) => any | Promise<any>
+
+type asyncPipe = (...fns: Func[]) => (v?: any) => Promise<any>
+export const asyncPipe: asyncPipe = (...fns) => v => fns.reduce(async (a, c) => c(await a), v)

tests/unit/index.ts

@@ -14,6 +14,7 @@ import '../../src/Helpers/Configuration.test'
 import '../../src/Helpers/FetchError.test.ts'
 import '../../src/Helpers/Logging.test.ts'
 import '../../src/Helpers/Time.test.ts'
+import '../../src/Helpers/async-pipe.test.ts'
 import '../../src/Helpers/camelCaseToScreamingSnakeCase.test'
 import '../../src/Helpers/isTruthy.test'
 import '../../src/Helpers/to-promise.test.ts'