Linter fixes

.eslintrc.js

@@ -0,0 +1,47 @@
+// The ESLint ecmaVersion argument is inconsistently used. Some rules will ignore it entirely, so if the rule has
+// been set, it will still error even if it's not applicable to that version number. Since Google sets these
+// rules, we have to turn them off ourselves.
+const DISABLED_ES6_OPTIONS = {
+  'no-var': 'off',
+  'prefer-rest-params': 'off'
+};
+
+const SHAREDB_RULES = {
+  // Comma dangle is not supported in ES3
+  'comma-dangle': ['error', 'never'],
+  // We control our own objects and prototypes, so no need for this check
+  'guard-for-in': 'off',
+  // Google prescribes different indents for different cases. Let's just use 2 spaces everywhere. Note that we have
+  // to override ESLint's default of 0 indents for this.
+  'indent': ['error', 2, {
+    'SwitchCase': 1
+  }],
+  // Less aggressive line length than Google, which is especially useful when we have a lot of callbacks in our code
+  'max-len': ['error',
+    {
+      code: 120,
+      tabWidth: 2,
+      ignoreUrls: true,
+    }
+  ],
+  // Google overrides the default ESLint behaviour here, which is slightly better for catching erroneously unused variables
+  'no-unused-vars': ['error', {vars: 'all', args: 'after-used'}],
+  // It's more readable to ensure we only have one statement per line
+  'max-statements-per-line': ['error', {max: 1}],
+  // as-needed quote props are easier to write
+  'quote-props': ['error', 'as-needed'],
+  'require-jsdoc': 'off',
+  'valid-jsdoc': 'off'
+};
+
+module.exports = {
+  extends: 'google',
+  parserOptions: {
+    ecmaVersion: 3
+  },
+  rules: Object.assign(
+    {},
+    DISABLED_ES6_OPTIONS,
+    SHAREDB_RULES
+  ),
+};

.travis.yml

@@ -3,6 +3,6 @@ node_js:
   - "10"
   - "8"
   - "6"
-script: "npm run jshint && npm run test-cover"
+script: "npm run lint && npm run test-cover"
 # Send coverage data to Coveralls
 after_script: "cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js"

examples/counter/server.js

@@ -29,7 +29,7 @@ function startServer() {
 
   // Connect any incoming WebSocket connection to ShareDB
   var wss = new WebSocket.Server({server: server});
-  wss.on('connection', function(ws, req) {
+  wss.on('connection', function(ws) {
     var stream = new WebSocketJSONStream(ws);
     backend.listen(stream);
   });

examples/leaderboard/server/index.js

@@ -1,37 +1,38 @@
-var http = require("http");
-var ShareDB = require("sharedb");
-var connect = require("connect");
+var http = require('http');
+var ShareDB = require('sharedb');
+var connect = require('connect');
 var serveStatic = require('serve-static');
 var ShareDBMingoMemory = require('sharedb-mingo-memory');
 var WebSocketJSONStream = require('@teamwork/websocket-json-stream');
 var WebSocket = require('ws');
-var util = require('util');
 
 // Start ShareDB
-var share = ShareDB({db: new ShareDBMingoMemory()});
+var share = new ShareDB({db: new ShareDBMingoMemory()});
 
 // Create a WebSocket server
 var app = connect();
 app.use(serveStatic('.'));
 var server = http.createServer(app);
 var wss = new WebSocket.Server({server: server});
 server.listen(8080);
-console.log("Listening on http://localhost:8080");
+console.log('Listening on http://localhost:8080');
 
 // Connect any incoming WebSocket connection with ShareDB
-wss.on('connection', function(ws, req) {
+wss.on('connection', function(ws) {
   var stream = new WebSocketJSONStream(ws);
   share.listen(stream);
 });
 
 // Create initial documents
 var connection = share.connect();
 connection.createFetchQuery('players', {}, {}, function(err, results) {
-  if (err) { throw err; }
+  if (err) {
+    throw err;
+  }
 
   if (results.length === 0) {
-    var names = ["Ada Lovelace", "Grace Hopper", "Marie Curie",
-                 "Carl Friedrich Gauss", "Nikola Tesla", "Claude Shannon"];
+    var names = ['Ada Lovelace', 'Grace Hopper', 'Marie Curie',
+      'Carl Friedrich Gauss', 'Nikola Tesla', 'Claude Shannon'];
 
     names.forEach(function(name, index) {
       var doc = connection.get('players', ''+index);

examples/rich-text/server.js

@@ -32,7 +32,7 @@ function startServer() {
 
   // Connect any incoming WebSocket connection to ShareDB
   var wss = new WebSocket.Server({server: server});
-  wss.on('connection', function(ws, req) {
+  wss.on('connection', function(ws) {
     var stream = new WebSocketJSONStream(ws);
     backend.listen(stream);
   });

examples/textarea/client.js

@@ -2,35 +2,35 @@ var sharedb = require('sharedb/lib/client');
 var StringBinding = require('sharedb-string-binding');
 
 // Open WebSocket connection to ShareDB server
-const WebSocket = require('reconnecting-websocket');
+var WebSocket = require('reconnecting-websocket');
 var socket = new WebSocket('ws://' + window.location.host);
 var connection = new sharedb.Connection(socket);
 
 var element = document.querySelector('textarea');
 var statusSpan = document.getElementById('status-span');
-statusSpan.innerHTML = "Not Connected"
+statusSpan.innerHTML = 'Not Connected';
 
-element.style.backgroundColor = "gray";
-socket.onopen = function(){
-  statusSpan.innerHTML = "Connected"
-  element.style.backgroundColor = "white";
+element.style.backgroundColor = 'gray';
+socket.onopen = function() {
+  statusSpan.innerHTML = 'Connected';
+  element.style.backgroundColor = 'white';
 };
 
-socket.onclose = function(){
-  statusSpan.innerHTML = "Closed"
-  element.style.backgroundColor = "gray";
+socket.onclose = function() {
+  statusSpan.innerHTML = 'Closed';
+  element.style.backgroundColor = 'gray';
 };
 
 socket.onerror = function() {
-  statusSpan.innerHTML = "Error"
-  element.style.backgroundColor = "red";
-}
+  statusSpan.innerHTML = 'Error';
+  element.style.backgroundColor = 'red';
+};
 
 // Create local Doc instance mapped to 'examples' collection document with id 'textarea'
 var doc = connection.get('examples', 'textarea');
 doc.subscribe(function(err) {
   if (err) throw err;
-  
+
   var binding = new StringBinding(element, doc, ['content']);
   binding.setup();
 });

examples/textarea/server.js

@@ -14,7 +14,7 @@ function createDoc(callback) {
   doc.fetch(function(err) {
     if (err) throw err;
     if (doc.type === null) {
-      doc.create({ content: '' }, callback);
+      doc.create({content: ''}, callback);
       return;
     }
     callback();
@@ -29,7 +29,7 @@ function startServer() {
 
   // Connect any incoming WebSocket connection to ShareDB
   var wss = new WebSocket.Server({server: server});
-  wss.on('connection', function(ws, req) {
+  wss.on('connection', function(ws) {
     var stream = new WebSocketJSONStream(ws);
     backend.listen(stream);
   });

lib/agent.js

@@ -56,7 +56,6 @@ Agent.prototype.close = function(err) {
 };
 
 Agent.prototype._cleanup = function() {
-
   // Only clean up once if the stream emits both 'end' and 'close'.
   if (this.closed) return;
 
@@ -265,7 +264,7 @@ Agent.prototype._open = function() {
       agent._handleMessage(request.data, callback);
     });
   });
-  
+
   var cleanup = agent._cleanup.bind(agent);
   this.stream.on('end', cleanup);
   this.stream.on('close', cleanup);
@@ -333,7 +332,9 @@ Agent.prototype._handleMessage = function(request, callback) {
 };
 function getQueryOptions(request) {
   var results = request.r;
-  var ids, fetch, fetchOps;
+  var ids;
+  var fetch;
+  var fetchOps;
   if (results) {
     ids = [];
     for (var i = 0; i < results.length; i++) {
@@ -362,7 +363,6 @@ function getQueryOptions(request) {
 
 Agent.prototype._queryFetch = function(queryId, collection, query, options, callback) {
   // Fetch the results of a query once
-  var agent = this;
   this.backend.queryFetch(this, collection, query, options, function(err, results, extra) {
     if (err) return callback(err);
     var message = {
@@ -607,10 +607,10 @@ Agent.prototype._createOp = function(request) {
   }
 };
 
-Agent.prototype._fetchSnapshot = function (collection, id, version, callback) {
+Agent.prototype._fetchSnapshot = function(collection, id, version, callback) {
   this.backend.fetchSnapshot(this, collection, id, version, callback);
 };
 
-Agent.prototype._fetchSnapshotByTimestamp = function (collection, id, timestamp, callback) {
+Agent.prototype._fetchSnapshotByTimestamp = function(collection, id, timestamp, callback) {
   this.backend.fetchSnapshotByTimestamp(this, collection, id, timestamp, callback);
 };