handle pause and start similar to current behaviour

Author: amrlabib

.eslintrc

@@ -7,6 +7,7 @@
     "react-hooks/rules-of-hooks": "error",
     "react-hooks/exhaustive-deps": "warn",
     "react/jsx-filename-extension": 0,
+    "import/prefer-default-export": 0,
     "no-unused-expressions": [ 2,{
       "allowShortCircuit": true,
     }],

src/useTimer.js

@@ -1,11 +1,12 @@
-import { useState, useEffect } from 'react';
+import { useState } from 'react';
 import { Time, Validate } from './utils';
 import { useInterval } from './hooks';
 
 export default function useTimer({ expiryTimestamp: expiry, onExpire, autoStart }) {
   const [expiryTimestamp, setExpiryTimestamp] = useState(expiry);
   const [seconds, setSeconds] = useState(Time.getSecondsFromExpiry(expiryTimestamp));
-  const [isRunning, setIsRunning] = useState(false);
+  const [isRunning, setIsRunning] = useState(autoStart);
+  const [didStart, setDidStart] = useState(autoStart);
 
   function handleExpire() {
     Validate.onExpire(onExpire) && onExpire();
@@ -15,17 +16,22 @@ export default function useTimer({ expiryTimestamp: expiry, onExpire, autoStart
     setIsRunning(false);
   }
 
-  function start() {
-    setIsRunning(true);
-  }
-
   function resume() {
     const time = new Date();
     time.setSeconds(time.getSeconds() + seconds); // calculate new expiry timestamp based on last paused seconds count
     setExpiryTimestamp(time);
     setIsRunning(true);
   }
 
+  function start() {
+    if (didStart) {
+      setIsRunning(true);
+    } else {
+      resume();
+      setDidStart(true);
+    }
+  }
+
   function restart(newExpiryTimestamp) {
     setExpiryTimestamp(newExpiryTimestamp);
     setSeconds(Time.getSecondsFromExpiry(newExpiryTimestamp));
@@ -39,12 +45,6 @@ export default function useTimer({ expiryTimestamp: expiry, onExpire, autoStart
     setSeconds(secondsValue);
   } : () => {}, 1000);
 
-  useEffect(() => {
-    if (autoStart) {
-      setIsRunning(true);
-    }
-  }, [autoStart]);
-
   return {
     ...Time.getTimeFromSeconds(seconds), start, pause, resume, restart, isRunning,
   };