fix: Convert TimeInterval.js back to CommonJS

Previously, this file was `TimeInterval.mjs` and exported things with
ESM. This was originally done to make Vite happy, but however, this
didn't actually work server-side. This is because the server is written
in CommonJS - and to import ESM from CommonJS, one needs to use dynamic
import. And, since the imports are at the top of the file, TLA
(top-level await) must be active so the module is implemented
(rather than Promise<Module>, which was previously occuring). And, TLA
is only available in ECMAScript Modules. Migrating everything to ESM would
take a lot of work, and it's not guaranteed everything will work the same.

So revisit keeping `TimeInterval.js` CommonJS. This was previously not
possible becaues Vite errored out. But now, Vite accepts this perfectly
fine.

package.json

@@ -60,7 +60,6 @@
 			"react-dom": "$react-dom"
 		},
 		"@formatjs/ecma402-abstract": "1.13.0"
-
 	},
 	"dependencies": {
 		"@formatjs/intl": "~1.17.0",

src/common/TimeInterval.js

@@ -0,0 +1,105 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+const moment = require('moment')
+
+exports.TimeInterval = class TimeInterval {
+	constructor(startTimestamp, endTimestamp) {
+		// utc keeps the moments from changing timezone.
+		this.startTimestamp = startTimestamp && moment.utc(startTimestamp);
+		this.endTimestamp = endTimestamp && moment.utc(endTimestamp);
+		this.isBounded = (this.startTimestamp !== null) && (this.endTimestamp !== null);
+	}
+
+	toString() {
+		if (this.isBounded) {
+			// Using '_' as a separator character since it doesn't appear in ISO dates
+			if (this.startTimestamp === undefined || this.endTimestamp === undefined) {
+				throw Error('startTimestamp or endTimestamp was undefined in a bounded TimeInterval');
+			}
+			return `${this.startTimestamp.format()}_${this.endTimestamp.format()}`;
+		}
+		return 'all';
+	}
+
+	equals(other) {
+		return (other instanceof TimeInterval) && this.toString() === other.toString();
+	}
+
+	/**
+	 * Returns the duration of the time interval
+	 * @param specifier - Optional parameter, defaults to milliseconds
+	 * @returns {number}
+	 */
+	duration(specifier) {
+		if (specifier) {
+			return this.endTimestamp.diff(this.startTimestamp, specifier);
+		}
+		return this.endTimestamp.diff(this.startTimestamp);
+	}
+
+	/**
+	 * Test if this time interval is contains another.
+	 * Intervals are considered to contain equal intervals.
+	 * @param other
+	 * @return {boolean}
+	 */
+	contains(other) {
+		if (!(other instanceof TimeInterval)) {
+			throw new Error('TimeInterval objects can only be compared to other TimeInterval objects');
+		}
+		/* The logic here is:
+		 *
+		 * THIS starts at -∞ OR not after OTHER
+		 * AND
+		 * THIS ends at +∞ OR not before OTHER
+		 */
+		return (
+			((this.startTimestamp === null) || (this.startTimestamp <= other.startTimestamp))
+			&&
+			((this.endTimestamp === null) || (this.endTimestamp >= other.endTimestamp))
+		);
+	}
+
+	/**
+	 * Returns TimeInterval.toString() so that using a time interval as an object key will
+	 * have reasonable behaviour.
+	 * @return {*}
+	 */
+	valueOf() {
+		return this.toString();
+	}
+
+	getStartTimestamp() {
+		return this.startTimestamp;
+	}
+
+	getEndTimestamp() {
+		return this.endTimestamp;
+	}
+
+	/**
+	 * Creates a new unbounded time interval
+	 * @return {TimeInterval}
+	 */
+	static unbounded() {
+		return new TimeInterval(null, null);
+	}
+
+	/**
+	 * Creates a new TimeInterval from its string representation
+	 * @param {string} stringified the string representation
+	 * @return {TimeInterval}
+	 */
+	static fromString(stringified) {
+		if (stringified === 'all') {
+			return TimeInterval.unbounded();
+		}
+		// Using '_' as a separator character since it doesn't appear in ISO dates
+		const [startTimestamp, endTimestamp] = stringified.split('_').map(timestamp => moment(timestamp));
+		return new TimeInterval(startTimestamp, endTimestamp);
+	}
+}

src/server/models/Baseline.js

@@ -3,7 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 const database = require('./database');
-const { TimeInterval } = import('../../common/TimeInterval.mjs');
+const { TimeInterval } = require('../../common/TimeInterval.js');
 const sqlFile = database.sqlFile;
 class Baseline {
 	constructor(meterID, applyStart, applyEnd, calcStart, calcEnd, note = null, baselineValue = null) {

src/server/routes/readings.js

@@ -7,7 +7,7 @@ const _ = require('lodash');
 const moment = require('moment');
 const Meter = require('../models/Meter');
 const Reading = require('../models/Reading');
-const { TimeInterval } = import('../../common/TimeInterval.mjs');
+const { TimeInterval } = require('../../common/TimeInterval.js');
 const { log } = require('../log');
 const validate = require('jsonschema').validate;
 const { getConnection } = require('../db');

src/server/routes/unitReadings.js

@@ -10,7 +10,7 @@ const _ = require('lodash');
 
 const { getConnection } = require('../db');
 const Reading = require('../models/Reading');
-const { TimeInterval } = import('../../common/TimeInterval.mjs');
+const { TimeInterval } = require('../../common/TimeInterval.js');
 
 function validateMeterLineReadingsParams(params) {
 	const validParams = {

src/server/test/routes/unitReadingsRouteTests.js

@@ -21,7 +21,7 @@ const { meterLineReadings,
 	validateBarReadingsQueryParams
 } = require('../../routes/unitReadings');
 
-const { TimeInterval } = import('../../../common/TimeInterval.mjs');
+const { TimeInterval } = require('../../../common/TimeInterval.js');
 
 function mockResponse() {
 	return {

src/server/test/timeIntervalTests.js

@@ -8,7 +8,7 @@ const chai = require('chai');
 const chaiAsPromised = require('chai-as-promised');
 chai.use(chaiAsPromised);
 const expect = chai.expect;
-const { TimeInterval } = import('../../common/TimeInterval.mjs');
+const { TimeInterval } = require('../../common/TimeInterval.js');
 
 
 mocha.describe('Time Intervals', () => {

src/server/test/web/readings.js

@@ -14,7 +14,7 @@
 */
 
 const { chai, mocha, expect, app, testDB } = require('../common');
-const { TimeInterval } = import('../../../common/TimeInterval.mjs');
+const { TimeInterval } = require('../../../common/TimeInterval.js');
 const { insertUnits, insertConversions, insertMeters, insertGroups } = require('../../util/insertData');
 const Unit = require('../../models/Unit');
 const { redoCik } = require('../../services/graph/redoCik');