refactor and remove coverage dependencies

Author: grindcode

.travis.yml

@@ -1,13 +1,7 @@
 language: node_js
 node_js:
-  - '9'
-  - '8'
-  - '7'
-  - '6'
   - 'lts/*'
   - 'node'
 branches:
   only:
-  - master
-after_script:
-  - npm run report
+  - master

README.md

@@ -1,7 +1,7 @@
 # Elastic Loop
-[![Build Status](https://travis-ci.org/grindcode/elastic-loop.svg?branch=master)](https://travis-ci.org/grindcode/elastic-loop) [![Test Coverage](https://codeclimate.com/github/grindcode/elastic-loop/badges/coverage.svg)](https://codeclimate.com/github/grindcode/elastic-loop/coverage) [![Dependency Status](https://david-dm.org/grindcode/elastic-loop.svg)](https://david-dm.org/grindcode/elastic-loop) [![devDependency Status](https://david-dm.org/grindcode/elastic-loop/dev-status.svg)](https://david-dm.org/grindcode/elastic-loop#info=devDependencies)
+[![Build Status](https://travis-ci.org/grindcode/elastic-loop.svg?branch=master)](https://travis-ci.org/grindcode/elastic-loop) [![Dependency Status](https://david-dm.org/grindcode/elastic-loop.svg)](https://david-dm.org/grindcode/elastic-loop) [![devDependency Status](https://david-dm.org/grindcode/elastic-loop/dev-status.svg)](https://david-dm.org/grindcode/elastic-loop#info=devDependencies)
 
-Runs an interval with elastic timeout. Useful for loops supporting heavy load situations.
+Runs an interval with variable timeout. Useful for loops adapting to heavy load or other kind of situations.
 
 ## Get Started
 ```bash
@@ -21,22 +21,22 @@ Runs `function` in loop, mutating timeout depending on `stress`. Returns instanc
 
 ### Usage
 ```javascript
-var loop = require('elastic-loop')
-var busy = require('node-busy')
+const loop = require('elastic-loop')
+const busy = require('node-busy')
 
-monitor = busy()
+const monitor = busy()
 
 // @cycle: current cycle fingerprint
-var run = function (cycle) {
+function run (cycle) {
   // → @cycle: { timeout: 1000, stress: 1 }
 }
 
-var stress = function () {
+function stress () {
   // returns true if overloaded, false otherwise
   return monitor.blocked
 }
 
-var cycle = loop(run, stress)
+const cycle = loop(run, stress)
 
 // cycle.end()
 

index.js

@@ -1,36 +1,36 @@
-module.exports = function (fn, lever, opts) {
-  var stress = 1
-  var cycle
-  var options = Object.assign({
-    modifier: 1.20, timeout: 1000, min: 1, max: 0
-  }, opts)
-  var increase = function () {
-    var s = stress * options.modifier
-    return (s < options.max || !options.max)? s: options.max
-  }
-  var decrease = function () {
-    var s = stress / options.modifier
-    return (s > options.min)? s: options.min
-  }
-  var balance = function () {
-    var s = stress
-    stress = (lever())? increase(): decrease()
-    return stress !== s
-  }
-  var end = function () {
-    clearInterval(cycle)
-  }
-  var run = function () {
-    var timeout = options.timeout * stress
-    var runInterval = function () {
-      fn({ stress: stress, timeout: timeout })
-      if (balance()) run()
+module.exports = function (fn, relay, options = {}) {
+    const {modifier = 1.20, timeout = 1000, min = 1, max = 0} = options
+    let stress = 1
+    let cycle
+    function increase () {
+        const nextStress = stress * modifier
+        return (nextStress < max || !max) ? nextStress : max
     }
-    end()
-    cycle = setInterval(runInterval, timeout)
-  }
-  run()
-  return {
-    end: end
-  }
+    function decrease () {
+        const nextStress = stress / modifier
+        return nextStress > min ? nextStress : min
+    }
+    function balance () {
+        const prevStress = stress
+        stress = relay() ? increase() : decrease()
+        return prevStress !== stress
+    }
+    function start (nextTimeout) {
+        cycle = setInterval(run, nextTimeout)
+    }
+    function run () {
+        const nextTimeout = timeout * stress
+        fn({stress, timeout: nextTimeout, cycle})
+        if (balance()) {
+            clear()
+            start(nextTimeout)
+        }
+    }
+    function clear () {
+        if (cycle) {
+            clearInterval(cycle)
+        }
+    }
+    start()
+    return clear
 }