Convert backend code to ES modules

Bundling code now with Rollup for its flat bundling and tree shaking
support. Front end code still goes through Webpack for browser support.

lib/db.js

@@ -18,12 +18,12 @@
  */
 "use strict";
 
-const mongodb = require("mongodb");
-const config = require("./config");
-const common = require("./common");
-const expressionParser = require("./common/expression-parser");
+import { MongoClient, ObjectID } from "mongodb";
+import { get } from "./config";
+import { escapeRegExp } from "./common";
+import { parse } from "./common/expression-parser";
 
-let tasksCollection,
+export let tasksCollection,
   devicesCollection,
   presetsCollection,
   objectsCollection,
@@ -34,32 +34,28 @@ let tasksCollection,
   operationsCollection,
   configCollection;
 
-function connect(callback) {
-  mongodb.MongoClient.connect(
-    config.get("MONGODB_CONNECTION_URL"),
+export let client;
+
+export function connect(callback) {
+  MongoClient.connect(
+    get("MONGODB_CONNECTION_URL"),
     { useNewUrlParser: true },
-    (err, client) => {
+    (err, _client) => {
       if (err) return void callback(err);
-      exports.client = client;
+      client = _client;
       const db = client.db();
 
-      exports.tasksCollection = tasksCollection = db.collection("tasks");
+      tasksCollection = db.collection("tasks");
       tasksCollection.createIndex({ device: 1, timestamp: 1 });
 
-      exports.devicesCollection = devicesCollection = db.collection("devices");
-      exports.presetsCollection = presetsCollection = db.collection("presets");
-      exports.objectsCollection = objectsCollection = db.collection("objects");
-      exports.filesCollection = filesCollection = db.collection("fs.files");
-      exports.provisionsCollection = provisionsCollection = db.collection(
-        "provisions"
-      );
-      exports.virtualParametersCollection = virtualParametersCollection = db.collection(
-        "virtualParameters"
-      );
-      exports.faultsCollection = faultsCollection = db.collection("faults");
-      exports.operationsCollection = operationsCollection = db.collection(
-        "operations"
-      );
+      devicesCollection = db.collection("devices");
+      presetsCollection = db.collection("presets");
+      objectsCollection = db.collection("objects");
+      filesCollection = db.collection("fs.files");
+      provisionsCollection = db.collection("provisions");
+      virtualParametersCollection = db.collection("virtualParameters");
+      faultsCollection = db.collection("faults");
+      operationsCollection = db.collection("operations");
       configCollection = db.collection("config");
 
       callback();
@@ -67,8 +63,8 @@ function connect(callback) {
   );
 }
 
-function disconnect() {
-  if (exports.client) exports.client.close();
+export function disconnect() {
+  if (client) client.close();
 }
 
 // Optimize projection by removing overlaps
@@ -92,8 +88,8 @@ function optimizeProjection(obj) {
   return obj;
 }
 
-function fetchDevice(id, timestamp, patterns, callback) {
-  const MAX_DEPTH = config.get("MAX_DEPTH", id);
+export function fetchDevice(id, timestamp, patterns, callback) {
+  const MAX_DEPTH = get("MAX_DEPTH", id);
 
   if (!patterns || !patterns.length) patterns = [[[], (1 << MAX_DEPTH) - 1]];
 
@@ -476,7 +472,13 @@ function fetchDevice(id, timestamp, patterns, callback) {
   });
 }
 
-function saveDevice(deviceId, deviceData, isNew, sessionTimestamp, callback) {
+export function saveDevice(
+  deviceId,
+  deviceData,
+  isNew,
+  sessionTimestamp,
+  callback
+) {
   const update = { $set: {}, $unset: {}, $addToSet: {}, $pull: {} };
 
   for (const diff of deviceData.timestamps.diff()) {
@@ -724,9 +726,9 @@ function saveDevice(deviceId, deviceData, isNew, sessionTimestamp, callback) {
   );
 }
 
-function getFaults(deviceId, callback) {
+export function getFaults(deviceId, callback) {
   faultsCollection
-    .find({ _id: { $regex: `^${common.escapeRegExp(deviceId)}\\:` } })
+    .find({ _id: { $regex: `^${escapeRegExp(deviceId)}\\:` } })
     .toArray((err, res) => {
       if (err) return callback(err);
 
@@ -745,7 +747,7 @@ function getFaults(deviceId, callback) {
     });
 }
 
-function saveFault(deviceId, channel, fault, callback) {
+export function saveFault(deviceId, channel, fault, callback) {
   const id = `${deviceId}:${channel}`;
   fault = Object.assign({}, fault);
   fault._id = id;
@@ -756,11 +758,11 @@ function saveFault(deviceId, channel, fault, callback) {
   faultsCollection.replaceOne({ _id: id }, fault, { upsert: true }, callback);
 }
 
-function deleteFault(deviceId, channel, callback) {
+export function deleteFault(deviceId, channel, callback) {
   faultsCollection.deleteOne({ _id: `${deviceId}:${channel}` }, callback);
 }
 
-function getDueTasks(deviceId, timestamp, callback) {
+export function getDueTasks(deviceId, timestamp, callback) {
   const cur = tasksCollection.find({ device: deviceId }).sort(["timestamp"]);
   const tasks = [];
 
@@ -782,8 +784,8 @@ function getDueTasks(deviceId, timestamp, callback) {
       // For API compatibility
       if (task.name === "download" && task.file) {
         let q;
-        if (mongodb.ObjectID.isValid(task.file))
-          q = { _id: { $in: [task.file, new mongodb.ObjectID(task.file)] } };
+        if (ObjectID.isValid(task.file))
+          q = { _id: { $in: [task.file, new ObjectID(task.file)] } };
         else q = { _id: task.file };
 
         filesCollection.find(q).toArray((err, res) => {
@@ -805,16 +807,16 @@ function getDueTasks(deviceId, timestamp, callback) {
   );
 }
 
-function clearTasks(deviceId, taskIds, callback) {
+export function clearTasks(deviceId, taskIds, callback) {
   tasksCollection.deleteMany(
-    { _id: { $in: taskIds.map(id => new mongodb.ObjectID(id)) } },
+    { _id: { $in: taskIds.map(id => new ObjectID(id)) } },
     callback
   );
 }
 
-function getOperations(deviceId, callback) {
+export function getOperations(deviceId, callback) {
   operationsCollection
-    .find({ _id: { $regex: `^${common.escapeRegExp(deviceId)}\\:` } })
+    .find({ _id: { $regex: `^${escapeRegExp(deviceId)}\\:` } })
     .toArray((err, res) => {
       if (err) return void callback(err);
 
@@ -833,7 +835,7 @@ function getOperations(deviceId, callback) {
     });
 }
 
-function saveOperation(deviceId, commandKey, operation, callback) {
+export function saveOperation(deviceId, commandKey, operation, callback) {
   const id = `${deviceId}:${commandKey}`;
   operation = Object.assign({}, operation);
   operation._id = id;
@@ -849,34 +851,34 @@ function saveOperation(deviceId, commandKey, operation, callback) {
   );
 }
 
-function deleteOperation(deviceId, commandKey, callback) {
+export function deleteOperation(deviceId, commandKey, callback) {
   operationsCollection.deleteOne(
     { _id: `${deviceId}:${commandKey}` },
     callback
   );
 }
 
-function getPresets(callback) {
+export function getPresets(callback) {
   presetsCollection.find().toArray(callback);
 }
 
-function getObjects(callback) {
+export function getObjects(callback) {
   objectsCollection.find().toArray(callback);
 }
 
-function getProvisions(callback) {
+export function getProvisions(callback) {
   provisionsCollection.find().toArray(callback);
 }
 
-function getVirtualParameters(callback) {
+export function getVirtualParameters(callback) {
   virtualParametersCollection.find().toArray(callback);
 }
 
-function getFiles(callback) {
+export function getFiles(callback) {
   filesCollection.find().toArray(callback);
 }
 
-function getConfig(callback) {
+export function getConfig(callback) {
   configCollection.find().toArray((err, res) => {
     if (err) return void callback(err);
 
@@ -884,27 +886,8 @@ function getConfig(callback) {
       null,
       res.map(c => ({
         id: c["_id"],
-        value: expressionParser.parse(c["value"])
+        value: parse(c["value"])
       }))
     );
   });
 }
-
-exports.connect = connect;
-exports.disconnect = disconnect;
-exports.fetchDevice = fetchDevice;
-exports.saveDevice = saveDevice;
-exports.getFaults = getFaults;
-exports.saveFault = saveFault;
-exports.deleteFault = deleteFault;
-exports.clearTasks = clearTasks;
-exports.saveOperation = saveOperation;
-exports.deleteOperation = deleteOperation;
-exports.getPresets = getPresets;
-exports.getObjects = getObjects;
-exports.getProvisions = getProvisions;
-exports.getVirtualParameters = getVirtualParameters;
-exports.getFiles = getFiles;
-exports.getDueTasks = getDueTasks;
-exports.getOperations = getOperations;
-exports.getConfig = getConfig;