error handling

package-lock.json

@@ -1,5 +1,5 @@
 {
   "name": "safe-redis-leader",
-  "version": "0.0.1",
+  "version": "0.0.4",
   "lockfileVersion": 1
 }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "safe-redis-leader",
-  "version": "0.0.4",
+  "version": "0.0.5",
   "description": "Redis leader election implementation that does not have any race conditions",
   "main": "src/src/index.js",
   "scripts": {

src/src/index.js

@@ -26,37 +26,41 @@ async function createSafeRedisLeader({
   let renewTimeoutId,
       electTimeoutId
 
+  let isStarted = false
+
 
 
   async function renew(){
-    const leading = await isLeader()
-    if(leading){
-      await asyncRedis.pexpire(key, ttl)
-      setTimeout(renew, ttl / 2)
-    }
-    else{
-      clearTimeout(renewTimeoutId)
-      electTimeoutId = setTimeout(elect, wait);
-    }
+    await emitOnError(async ()=>{
+      const leading = await isLeader()
+      if(leading){
+        await asyncRedis.pexpire(key, ttl)
+        setTimeout(renew, ttl / 2)
+      }
+      else{
+        clearTimeout(renewTimeoutId)
+        electTimeoutId = setTimeout(elect, wait);
+      }
+    })
   }
 
+  async function runElection(){
+    await emitOnError(async ()=>{
+      const res = await asyncRedis.set(key, id, 'PX', ttl, 'NX')
+
+      if(res !== null) {
+        emitter.emit('elected')
+        renewTimeoutId = setTimeout(renew, ttl / 2)
+      } 
+      else{
+        electTimeoutId = setTimeout(elect, wait)
+      }
+    })
+  }
 
   async function elect(){
-    let res
-    try{
-      res = await asyncRedis.set(key, id, 'PX', ttl, 'NX')
-    }
-    catch(e){
-      return emitter.emit('error', e)
-    }
-
-    if(res !== null) {
-      emitter.emit('elected')
-      renewTimeoutId = setTimeout(renew, ttl / 2)
-    } 
-    else{
-      electTimeoutId = setTimeout(elect, wait)
-    }
+    isStarted = true
+    await runElection()
   }
 
 
@@ -88,7 +92,19 @@ async function createSafeRedisLeader({
     emitter.removeAllListeners()
   }
 
+  async function emitOnError(fn){
+    try{
+      await fn()
+    }
+    catch(e){
+      if(isStarted){
+        emitter.emit('error', e)
+      }
+    }
+  }
+
   async function shutdown(){
+    isStarted = false
     renewTimeoutId && clearTimeout(renewTimeoutId) 
     electTimeoutId && clearTimeout(electTimeoutId)
     await stop()

src/src/testHelpers/index.js

@@ -14,4 +14,11 @@ async function tryCatchIgnore(fn, errorMessage){
   }
 }
 
-module.exports.tryCatchIgnore = tryCatchIgnore
+module.exports.tryCatchIgnore = tryCatchIgnore
+
+
+async function delay(ms) {
+  return new Promise(resolve => setTimeout(resolve, ms))
+}
+
+module.exports.delay = delay

src/src/tests/index.test.js

@@ -1,6 +1,6 @@
 const {createSafeRedisLeader} = require('../index')
 const connectToRedis = require('../../library/connect-to-redis')
-const {tryCatchIgnore} = require('../testHelpers')
+const {tryCatchIgnore, delay} = require('../testHelpers')
 
 describe("createSafeRedisLeader", function(){
   afterEach(async function(){
@@ -18,7 +18,7 @@ describe("createSafeRedisLeader", function(){
       wait: 3000,
       key
     })
-
+    await delay(1000)
 
   })
 })