Add write recording capabilities to the mock bindings (#1249)

reconbot · web-flow · commit e8d9d2b16c66 · 2017-07-22T10:42:32.000-07:00
- change echo default
- add a bunch of logging and serialport serialnumbers
diff --git a/.docs/README.hbs b/.docs/README.hbs
@@ -330,8 +330,8 @@ Testing is an important feature of any library. To aid in our own tests we've de
 const SerialPort = require('serialport/test');
 const MockBinding = SerialPort.Binding;
 
-// Create a port and disable the echo.
-MockBinding.createPort('/dev/ROBOT', { echo: false });
+// Create a port and enable the echo and recording.
+MockBinding.createPort('/dev/ROBOT', { echo: true, record: true })
 cont port = new SerialPort('/dev/ROBOT')
 ```
 
diff --git a/README.md b/README.md
@@ -377,8 +377,8 @@ Testing is an important feature of any library. To aid in our own tests we've de
 const SerialPort = require('serialport/test');
 const MockBinding = SerialPort.Binding;
 
-// Create a port and disable the echo.
-MockBinding.createPort('/dev/ROBOT', { echo: false });
+// Create a port and enable the echo and recording.
+MockBinding.createPort('/dev/ROBOT', { echo: true, record: true })
 cont port = new SerialPort('/dev/ROBOT')
 ```
 
diff --git a/examples/mocking.js b/examples/mocking.js
@@ -8,11 +8,16 @@ const MockBinding = SerialPort.Binding;
 
 const portPath = 'COM_ANYTHING';
 
-// By default the mock bindings pretend to be an arduino with the `arduinoEcho` program loaded.
+// The mock bindings can pretend to be an arduino with the `arduinoEcho` program loaded.
 // This will echo any byte written to the port and will emit "READY" data after opening.
+// You enable this by passing `echo: true`
 
-// Create a port and disable the echo.
-MockBinding.createPort(portPath, { echo: false });
+// Another additional option is `record`, if `record: true` is present all
+// writes will be recorded into a single buffer for the lifetime of the port
+// it can be read from `port.binding.recording`.
+
+// Create a port
+MockBinding.createPort(portPath, { echo: false, record: false });
 
 const port = new SerialPort(portPath);
 port.on('open', () => {
diff --git a/lib/bindings/mock.js b/lib/bindings/mock.js
@@ -1,8 +1,10 @@
 'use strict';
+const debug = require('debug')('serialport:bindings:mock');
 const Buffer = require('safe-buffer').Buffer;
 const BaseBinding = require('./base');
 
 let ports = {};
+let serialNumber = 0;
 
 function resolveNextTick() {
   return new Promise(resolve => process.nextTick(resolve));
@@ -15,6 +17,7 @@ class MockBinding extends BaseBinding {
     this.isOpen = false;
     this.port = null;
     this.lastWrite = null;
+    this.recording = new Buffer(0);
     this.pendingWrite = null;
   }
 
@@ -25,25 +28,29 @@ class MockBinding extends BaseBinding {
 
   // Create a mock port
   static createPort(path, opt) {
+    serialNumber++;
     opt = Object.assign({
-      echo: true,
+      echo: false,
+      record: false,
       readyData: Buffer.from('READY')
     }, opt);
 
     ports[path] = {
       data: Buffer.alloc(0),
       echo: opt.echo,
-      readyData: opt.readyData,
+      record: opt.record,
+      readyData: Buffer.from(opt.readyData),
       info: {
         comName: path,
         manufacturer: 'The J5 Robotics Company',
-        serialNumber: undefined,
+        serialNumber,
         pnpId: undefined,
         locationId: undefined,
         vendorId: undefined,
         productId: undefined
       }
     };
+    debug(serialNumber, 'created port', JSON.stringify({ path, opt }));
   }
 
   static list() {
@@ -58,21 +65,27 @@ class MockBinding extends BaseBinding {
     if (!this.isOpen) {
       throw new Error('Port must be open to pretend to receive data');
     }
+    if (!Buffer.isBuffer(data)) {
+      data = Buffer.from(data);
+    }
+    debug(this.serialNumber, 'emitting data - pending read:', Boolean(this.pendingRead));
     this.port.data = Buffer.concat([this.port.data, data]);
-
     if (this.pendingRead) {
       process.nextTick(this.pendingRead);
       this.pendingRead = null;
     }
   }
 
   open(path, opt) {
+    debug(null, `opening path ${path}`);
     const port = this.port = ports[path];
     return super.open(path, opt)
+      .then(resolveNextTick)
       .then(() => {
         if (!port) {
           return Promise.reject(new Error(`Port does not exist - please call MockBinding.createPort('${path}') first`));
         }
+        this.serialNumber = port.info.serialNumber;
 
         if (port.openOpt && port.openOpt.lock) {
           return Promise.reject(new Error('Port is locked cannot open'));
@@ -84,6 +97,7 @@ class MockBinding extends BaseBinding {
 
         port.openOpt = Object.assign({}, opt);
         this.isOpen = true;
+        debug(this.serialNumber, 'port is open');
         if (port.echo) {
           process.nextTick(() => {
             if (this.isOpen) { this.emitData(port.readyData) }
@@ -94,6 +108,7 @@ class MockBinding extends BaseBinding {
 
   close() {
     const port = this.port;
+    debug(this.serialNumber, 'closing port');
     if (!port) {
       return Promise.reject(new Error('close'));
     }
@@ -104,12 +119,15 @@ class MockBinding extends BaseBinding {
         // reset data on close
         port.data = Buffer.alloc(0);
 
+        debug(this.serialNumber, 'port is closed');
         delete this.port;
+        delete this.serialNumber;
         this.isOpen = false;
       });
   }
 
   read(buffer, offset, length) {
+    debug(this.serialNumber, 'reading', length, 'bytes');
     return super.read(buffer, offset, length)
       .then(resolveNextTick())
       .then(() => {
@@ -124,42 +142,52 @@ class MockBinding extends BaseBinding {
         const data = this.port.data.slice(0, length);
         const readLength = data.copy(buffer, offset);
         this.port.data = this.port.data.slice(length);
-
+        debug(this.serialNumber, 'read', readLength, 'bytes');
         return readLength;
       });
   }
 
   write(buffer) {
+    debug(this.serialNumber, 'writing');
+    if (this.pendingWrite) {
+      throw new Error('Overlapping writes are not supported and should be queued by the serialport object');
+    }
     this.pendingWrite = super.write(buffer)
-      .then(resolveNextTick())
+      .then(resolveNextTick)
       .then(() => {
         if (!this.isOpen) {
           throw new Error('Write canceled');
         }
         const data = this.lastWrite = Buffer.from(buffer); // copy
+        if (this.port.record) {
+          this.recording = Buffer.concat([this.recording, data]);
+        }
         if (this.port.echo) {
           process.nextTick(() => {
             if (this.isOpen) { this.emitData(data) }
           });
         }
         this.pendingWrite = null;
+        debug(this.serialNumber, 'writing finished');
       });
     return this.pendingWrite;
   }
 
   update(opt) {
     return super.update(opt)
+      .then(resolveNextTick)
       .then(() => {
         this.port.openOpt.baudRate = opt.baudRate;
       });
   }
 
   set(opt) {
-    return super.set(opt);
+    return super.set(opt).then(resolveNextTick);
   }
 
   get() {
     return super.get()
+      .then(resolveNextTick)
       .then(() => {
         return {
           cts: true,
@@ -171,10 +199,10 @@ class MockBinding extends BaseBinding {
 
   flush() {
     return super.flush()
+      .then(resolveNextTick)
       .then(() => {
         this.port.data = Buffer.alloc(0);
-      })
-      .then(resolveNextTick());
+      });
   }
 
   drain() {
