Uses an alternative wifi scan to produce consistent results

.jshintrc

@@ -15,6 +15,7 @@
   "strict": false,
   "esnext": true,
   "unused": true,
+  "evil" : true,
   "globals": {
     "exports": true,
     "document": true,

lib/controller.js

@@ -607,7 +607,7 @@ controller.printAvailableNetworks = function(opts) {
 
         // Print out networks
         networks.forEach(function(network) {
-          logs.info('\t', network.ssid, '(' + network.quality + '/' + network.quality_max + ')');
+          logs.info('\t', network.ssid, '(' + network.quality + ')');
         });
       });
   });

lib/tessel/commands.js

@@ -2,7 +2,7 @@ module.exports.readFile = function(filepath) {
   return ['cat', filepath];
 };
 module.exports.scanWiFi = function() {
-  return ['ubus', 'call', 'iwinfo', 'scan', '{"device":"wlan0"}'];
+  return ['iwinfo', 'wlan0', 'scan'];
 };
 module.exports.getWifiInfo = function() {
   return ['ubus', 'call', 'iwinfo', 'info', '{"device":"wlan0"}'];

lib/tessel/wifi.js

@@ -13,27 +13,31 @@ var Tessel = require('./tessel');
 Tessel.prototype.findAvailableNetworks = function() {
   logs.info('Scanning for available networks...');
   return this.simpleExec(commands.scanWiFi())
-    .then(function wifiScanResults(resultsJSON) {
-      // Parse the response
-      var networks = '';
-      try {
-        networks = JSON.parse(resultsJSON).results;
-      } catch (err) {
-        // Throw any unfortunate errors
-        return Promise.reject(err);
-      }
-
-      // Sort by signal strength
-      networks.sort(compareBySignal);
-
-      // Remove networks without SSIDs
-      networks.forEach(function(network, index) {
-        if (!network.ssid) {
-          networks.splice(index, 1);
+    .then(function wifiScanResults(resultsData) {
+      // For each string chunk
+      return resultsData.trim().split('\n\n').reduce((networks, entry) => {
+        try {
+
+          var ssidRegex = /ESSID: "(.*)"/;
+          var qualityRegex = /Quality: (.*)/;
+          var encryptionRegex = /Encryption: (.*)/;
+
+          var networkInfo = {
+            // Parse out the SSID
+            ssid: ssidRegex.exec(entry)[1],
+            // Parse out the quality of the connection
+            quality: qualityRegex.exec(entry)[1],
+            // Parse the security type - unused at the moment
+            security: encryptionRegex.exec(entry)[1],
+          };
+          // Add this parsed network to our array
+          networks.push(networkInfo);
+        } catch (err) {
+          // Suppress errors created by entries that cannot be parsed.
         }
-      });
 
-      return networks;
+        return networks;
+      }, []).sort(compareBySignal);
     });
 };
 
@@ -60,9 +64,10 @@ Tessel.prototype.getWifiInfo = function() {
 };
 
 function compareBySignal(a, b) {
-  if ((a.quality / a.quality_max) > (b.quality / b.quality_max)) {
+  // eval(quality) turns a string fraction like 21/70 into a decimal
+  if (eval(a.quality) > eval(b.quality)) {
     return -1;
-  } else if ((a.quality / a.quality_max) < (b.quality / b.quality_max)) {
+  } else if (eval(a.quality) < eval(b.quality)) {
     return 1;
   } else {
     return 0;

test/unit/wifi.js

@@ -27,9 +27,7 @@ exports['Tessel.prototype.findAvailableNetworks'] = {
         test.done();
       });
 
-    var networks = JSON.stringify({
-      results: []
-    });
+    var networks = '';
 
     this.tessel._rps.stdout.push(networks);
 
@@ -41,26 +39,28 @@ exports['Tessel.prototype.findAvailableNetworks'] = {
   someNetworks: function(test) {
     test.expect(2);
 
-    var networks = {
-      results: [{
-        ssid: 'ssid1',
-        quality: 21,
-        max_quality: 73,
-      }, {
-        ssid: 'ssid2',
-        quality: 5,
-        max_quality: 73,
-      }, ]
-    };
+    var networks =
+      `Cell 01 - Address: 14:35:8B:11:30:F0
+              ESSID: "technicallyHome"
+              Mode: Master  Channel: 11
+              Signal: -55 dBm  Quality: 55/70
+              Encryption: mixed WPA/WPA2 PSK (TKIP, CCMP)
+
+    Cell 02 - Address: 6C:70:9F:D9:7A:5C
+              ESSID: "Fried Chicken Sandwich"
+              Mode: Master  Channel: 2
+              Signal: -51 dBm  Quality: 59/70
+              Encryption: WPA2 PSK (CCMP)
 
+`;
     this.tessel.findAvailableNetworks()
       .then((found) => {
-        test.equal(found.length, networks.results.length);
+        test.equal(found.length, 2);
         test.equal(this.findAvailableNetworks.callCount, 1);
         test.done();
       });
 
-    this.tessel._rps.stdout.push(JSON.stringify(networks));
+    this.tessel._rps.stdout.push(networks);
 
     setImmediate(() => {
       this.tessel._rps.emit('close');
@@ -70,39 +70,37 @@ exports['Tessel.prototype.findAvailableNetworks'] = {
   compareSignalStrengths: function(test) {
     test.expect(5);
 
-    var bestNetwork = {
-      ssid: 'best',
-      quality: 60,
-      quality_max: 73,
-    };
 
-    var worstNetwork = {
-      ssid: 'worst',
-      quality: 5,
-      quality_max: 73,
-    };
+    var networks = `Cell 01 - Address: 14:35:8B:11:30:F0
+              ESSID: "middle"
+              Mode: Master  Channel: 11
+              Signal: -55 dBm  Quality: 30/70
+              Encryption: mixed WPA/WPA2 PSK (TKIP, CCMP)
 
-    var middleNetwork = {
-      ssid: 'middle',
-      quality: 10,
-      quality_max: 73,
-    };
+    Cell 02 - Address: 6C:70:9F:D9:7A:5C
+              ESSID: "worst"
+              Mode: Master  Channel: 2
+              Signal: -57 dBm  Quality: 5/70
+              Encryption: WPA2 PSK (CCMP)
 
-    var networks = {
-      results: [bestNetwork, worstNetwork, middleNetwork]
-    };
+    Cell 03 - Address: 6C:70:9F:D9:7A:5C
+            ESSID: "best"
+            Mode: Master  Channel: 2
+            Signal: -57 dBm  Quality: 60/70
+            Encryption: WPA2 PSK (CCMP)
 
+`;
     this.tessel.findAvailableNetworks()
       .then((found) => {
-        test.equal(found.length, networks.results.length);
+        test.equal(found.length, 3);
         test.equal(this.findAvailableNetworks.callCount, 1);
-        test.equal(found[0].ssid, bestNetwork.ssid);
-        test.equal(found[1].ssid, middleNetwork.ssid);
-        test.equal(found[2].ssid, worstNetwork.ssid);
+        test.equal(found[0].ssid, 'best');
+        test.equal(found[1].ssid, 'middle');
+        test.equal(found[2].ssid, 'worst');
         test.done();
       });
 
-    this.tessel._rps.stdout.push(JSON.stringify(networks));
+    this.tessel._rps.stdout.push(networks);
 
     setImmediate(() => {
       this.tessel._rps.emit('close');