Add debounce to tasq

packages/tasq/src/debounce.test.ts

@@ -0,0 +1,17 @@
+import {debounce} from './debounce'
+
+describe('debounce', () => {
+
+  it('executes only once', async () => {
+    const add = jest.fn()
+    const d = debounce(add, 0)
+    d(1, 2)
+    d(3, 4)
+    d(5, 6)
+    d(7, 8)
+
+    await new Promise(resolve => setTimeout(resolve, 0))
+    expect(add.mock.calls).toEqual([[ 7, 8 ]])
+  })
+
+})

packages/tasq/src/debounce.ts

@@ -0,0 +1,13 @@
+export function debounce<A, R>(fn: (...args: A[]) => R, delay: number) {
+  let timeout: NodeJS.Timeout | null = null
+
+  return async function debounceImpl(...args: A[]) {
+    if (timeout) {
+      clearTimeout(timeout)
+    }
+
+    timeout = setTimeout(() => {
+      fn(...args)
+    }, delay)
+  }
+}

packages/tasq/src/index.ts

@@ -1 +1 @@
-
+export * from './debounce'