Adding in port selection to serialport-term. (serialport#1448)

* Adding in port selection to serialport-term.

This makes the terminal command much more useable when you need to open
it multiple times in a row; especially when the names of the serialports
are rapidly changing.

* Fix the command line arguments.

* Fixing eslint mistakes.

* Make all of the negative errors positive in serialport-terminal.

bin/terminal.js

@@ -4,17 +4,17 @@
 const SerialPort = require('../lib/');
 const version = require('../package.json').version;
 const args = require('commander');
+const List = require('prompt-list');
 
 function makeNumber(input) {
   return Number(input);
 }
 
 args
   .version(version)
-  .usage('-p <port> [options]')
+  .usage('[options]')
   .description('A basic terminal interface for communicating over a serial port. Pressing ctrl+c exits.')
   .option('-l --list', 'List available ports then exit')
-  // TODO make the port not a flag as it's always required
   .option('-p, --port <port>', 'Path or Name of serial port')
   .option('-b, --baud <baudrate>', 'Baud rate default: 9600', makeNumber, 9600)
   .option('--databits <databits>', 'Data bits default: 8', makeNumber, 8)
@@ -36,21 +36,53 @@ function listPorts() {
   });
 };
 
-function createPort() {
-  if (!args.port) {
-    args.outputHelp();
-    args.missingArgument('port');
-    process.exit(-1);
+function setupPort() {
+  if (args.port) {
+    createPort(args.port);
   }
 
+  SerialPort.list((err, ports) => {
+    if (err) {
+      console.error('Error listing ports, and missing port argument.', err);
+      args.outputHelp();
+      args.missingArgument('port');
+      process.exit(4);
+    } else {
+      if (ports.length > 0) {
+        const portSelection = new List({
+          name: 'serial-port-selection',
+          message: 'Select a serial port to open',
+          choices: ports.map((port, i) => `[${i + 1}]\t${port.comName}\t${port.pnpId || ''}\t${port.manufacturer || ''}`)
+        });
+
+        portSelection.run()
+          .then(answer => {
+            const choice = answer.split('\t')[1];
+            console.log(`Opening serial port: ${choice}`);
+            createPort(choice);
+          })
+          .catch(error => {
+            console.log(`Could not select a port: ${error}`);
+            process.exit(2);
+          });
+      } else {
+        args.outputHelp();
+        args.missingArgument('port');
+        process.exit(3);
+      }
+    }
+  });
+}
+
+function createPort(selectedPort) {
   const openOptions = {
     baudRate: args.baud,
     dataBits: args.databits,
     parity: args.parity,
     stopBits: args.stopbits
   };
 
-  const port = new SerialPort(args.port, openOptions);
+  const port = new SerialPort(selectedPort, openOptions);
 
   process.stdin.resume();
   process.stdin.setRawMode(true);
@@ -82,5 +114,5 @@ function createPort() {
 if (args.list) {
   listPorts();
 } else {
-  createPort();
+  setupPort();
 }

package.json

@@ -62,6 +62,7 @@
     "nan": "^2.6.2",
     "prebuild-install": "^2.4.1",
     "promirepl": "^1.0.1",
+    "prompt-list": "^3.1.2",
     "safe-buffer": "^5.0.1"
   },
   "devDependencies": {
@@ -99,6 +100,7 @@
     "lint": "eslint lib test bin examples",
     "rebuild-all": "npm rebuild && node-gyp rebuild",
     "repl": "node bin/repl.js",
+    "terminal": "node bin/terminal.js",
     "stress": "mocha --no-timeouts test/arduinoTest/stress.js",
     "test": "istanbul cover ./node_modules/mocha/bin/_mocha",
     "test:watch": "mocha -w",