update queries to return consistent values

Server/db/mongo/modules/checkModule.js

@@ -123,8 +123,12 @@ const getChecksByMonitor = async (req) => {
 			},
 			{
 				$project: {
-					checksCount: { $arrayElemAt: ["$summary.checksCount", 0] },
-					checks: "$checks",
+					checksCount: {
+						$ifNull: [{ $arrayElemAt: ["$summary.checksCount", 0] }, 0],
+					},
+					checks: {
+						$ifNull: ["$checks", []],
+					},
 				},
 			},
 		]);

Server/db/mongo/modules/monitorModule.js

@@ -340,6 +340,7 @@ const getUptimeDetailsById = async (req) => {
 		};
 
 		const dateString = formatLookup[dateRange];
+
 		const results = await Check.aggregate(
 			buildUptimeDetailsPipeline(monitor, dates, dateString)
 		);

Server/db/mongo/modules/monitorModuleQueries.js

@@ -218,18 +218,20 @@ const buildUptimeDetailsPipeline = (monitor, dates, dateString) => {
 		{
 			$project: {
 				uptimeStreak: {
-					$cond: [
-						{ $eq: [{ $size: { $first: "$uptimeStreak.streak.checks" } }, 0] },
-						0,
-						{
-							$subtract: [
-								new Date(),
+					$let: {
+						vars: {
+							checks: { $ifNull: [{ $first: "$uptimeStreak.streak.checks" }, []] },
+						},
+						in: {
+							$cond: [
+								{ $eq: [{ $size: "$$checks" }, 0] },
+								0,
 								{
-									$last: { $first: "$uptimeStreak.streak.checks.createdAt" },
+									$subtract: [new Date(), { $last: "$$checks.createdAt" }],
 								},
 							],
 						},
-					],
+					},
 				},
 				avgResponseTime: {
 					$arrayElemAt: ["$aggregateData.avgResponseTime", 0],