working out promise sequence of init tasks

lib/interrupt.js

@@ -18,39 +18,40 @@ class Interrupt extends EventEmitter {
     this.num = pin_number;
     this.hook = opts.hook // will be passed back with the emit
     this.path = GPIO_ROOT_PATH + 'gpio' + this.num + '/'
-    this.edge = opts.edge ? opts.edge : 'falling'
-    this.delay = opts.delay ? opts.delay : 50
+    this.edge = opts.edge
+    this.delay = opts.delay
     this.dbt = opts.debounce ? opts.debounce : 300
-      // this.poller = new Epoll(
-      //   debounce((err, fd, events) => {
-      //     if (err) { this.emit('error', err) } else { this.clear().then(this.emit('fired', this.hook)) }
-      //   }, this.dbt, true)
-      // )
+    this.poller = new Epoll(
+      debounce((err, fd, events) => {
+        if (err) { this.emit('error', err) } else { this.clear().then(this.emit('fired', this.hook)) }
+      }, this.dbt, true)
+    )
   }
 
   init() {
 
-    let tasks = [
-      fs.writeFile(GPIO_ROOT_PATH + 'export', this.num).then(() => { console.log('exported', this.num) }),
-      pWaitFor(() => pathExists(this.path + 'direction')).then(_.pDelay(this.delay))
-      .then(() => { return fs.writeFile(this.path + 'direction', 'in').then(() => { console.log('direction', 'in') }) }),
-      fs.writeFile(this.path + 'edge', this.edge).then(() => { console.log('edge', this.edge) }),
-      fs.open(this.path + 'value', 'r+').then(fd => { this.valuefd = fd }),
-      this.clear().then(() => { return this.start() })
-    ]
-
     process.on('SIGINT', () => {
       this.exit().then(() => console.log('\nunexported and closed')) // unexport on cntrl-c
     })
 
-    return this.exit() // make sure pin is unexported
-      .then((resp) => {
-        console.log('ready to init', tasks)
-        return _.pSeries(tasks).then(console.log('finsihed tasks'))
+    return _.pSeries([
+      this.exit(),
+      this._export(this.num),
+      this._direction('in', this.delay),
+      () => this._edge(this.edge),
+      () => this._fd(),
+      () => this.clear().then(() => {
+        this.start()
+        return Promise.resolve('cleared and started')
       })
+    ])
 
   }
 
+  _test(num) {
+    return Promise.resolve(num)
+  }
+
   fire(name = 'fired') {
     this.emit(name, this.hook)
   }
@@ -62,16 +63,20 @@ class Interrupt extends EventEmitter {
 
   exit() {
     return pathExists(this.path)
-      .then(() => {
-        return fs.writeFile(GPIO_ROOT_PATH + 'unexport', this.num)
-      })
-      .then(() => {
-        if (this.valuefd) {
-          this.stop()
-          return fs.close(this.valuefd)
+      .then((exists) => {
+        // console.log('exists', exists)
+        if (exists) {
+          return fs.writeFile(GPIO_ROOT_PATH + 'unexport', this.num)
+            .then(() => {
+              if (this.valuefd) {
+                this.stop()
+                return fs.close(this.valuefd)
+              }
+              return Promise.resolve('unexported - exited')
+            })
         }
+        return Promise.resolve('already unexported')
       })
-      .catch(err => { return Promise.resolve('already unexported') })
   }
 
   start() {
@@ -82,6 +87,40 @@ class Interrupt extends EventEmitter {
     this.poller.remove(this.valuefd).close();
   }
 
+  _fd() {
+    return fs.open(this.path + 'value', 'r+')
+      .then(fd => {
+        this.valuefd = fd
+        return Promise.resolve('value fd set')
+      })
+  }
+
+  _export(num) {
+    return new Promise(function (resolve, reject) {
+      fs.writeFile(GPIO_ROOT_PATH + 'export', num)
+        .then(() => { return resolve('exported') })
+        .catch((err) => { return reject(err) })
+    })
+  }
+
+  _direction(dir = 'in', delay = 50) {
+    return pWaitFor(() => pathExists(this.path + 'direction'))
+      .then(_.pDelay(delay))
+      .then(() => {
+        return fs.writeFile(dir + 'direction', dir)
+          .then(() => {
+            return Promise.resolve('direction set')
+          })
+      })
+  }
+
+  _edge(edge = 'falling') {
+    return fs.writeFile(this.path + 'edge', edge)
+      .then(() => {
+        return Promise.resolve('edge set')
+      })
+  }
+
 }
 
 module.exports = {

test/interrupt.test.js

@@ -15,13 +15,15 @@ let inter17 = new Interrupt(17, { hook: 'a hook to something to do' })
 //   console.log('Listener fired and returned:', hook)
 // })
 
-// inter17.init()
-//   .then(() => {
-//     console.log('initialzed, waiting for interrupt to fire')
-//   })
-//   .catch(err => console.log("returned error:", err))
-//
-// inter17.on('fired', hook => { counter(hook) })
+inter17.init()
+  .then((resp) => {
+    console.log(resp)
+    console.log('initialzed, waiting for interrupt to fire')
+
+  })
+  .catch(err => console.log("returned error:", err))
+  //
+  // inter17.on('fired', hook => { counter(hook) })
 
 let count = 0