Move repeated time validation checks to utils.

Author: alserene

src/pages/ContextFeed.jsx

@@ -27,8 +27,8 @@ import {
   isoToUTC,
   getDayobsStartUTC,
   getDayobsEndUTC,
-  millisToDateTime,
   utcDateTimeStrToMillis,
+  getValidTimeRange,
 } from "@/utils/timeUtils";
 import { getDatetimeFromDayobsStr } from "@/utils/utils";
 
@@ -80,21 +80,7 @@ function ContextFeed() {
   const [selectedTimeRange, setSelectedTimeRange] = useState(() => {
     const startMillis = Number(startTime);
     const endMillis = Number(endTime);
-
-    const [fullStart, fullEnd] = fullTimeRange;
-
-    const isValid =
-      startMillis &&
-      endMillis &&
-      !Number.isNaN(startMillis) &&
-      !Number.isNaN(endMillis) &&
-      startMillis >= fullStart.toMillis() &&
-      endMillis <= fullEnd.toMillis();
-
-    if (isValid) {
-      return [millisToDateTime(startMillis), millisToDateTime(endMillis)];
-    }
-    return fullTimeRange;
+    return getValidTimeRange(startMillis, endMillis, fullTimeRange);
   });
 
   const [contextFeedData, setContextFeedData] = useState([]);
@@ -139,30 +125,11 @@ function ContextFeed() {
   useEffect(() => {
     const startMillis = Number(startTime);
     const endMillis = Number(endTime);
+    const newRange = getValidTimeRange(startMillis, endMillis, fullTimeRange);
 
-    // Url params are optional; make sure we don't set NaNs
-    const hasValidTimes =
-      startMillis != null &&
-      !Number.isNaN(startMillis) &&
-      endMillis != null &&
-      !Number.isNaN(endMillis);
-
-    // Only accept times if they fall inside the dayobs range
-    const hasTimesInRange =
-      startMillis >= fullTimeRange[0].toMillis() &&
-      endMillis <= fullTimeRange[1].toMillis();
-
-    const newRange =
-      hasValidTimes && hasTimesInRange
-        ? [millisToDateTime(startMillis), millisToDateTime(endMillis)]
-        : fullTimeRange;
-
-    // Only update state if the numeric values changed
-    const oldRange = selectedTimeRange;
     if (
-      !oldRange ||
-      oldRange[0].toMillis() !== newRange[0].toMillis() ||
-      oldRange[1].toMillis() !== newRange[1].toMillis()
+      newRange[0].toMillis() !== selectedTimeRange[0].toMillis() ||
+      newRange[1].toMillis() !== selectedTimeRange[1].toMillis()
     ) {
       setSelectedTimeRange(newRange);
     }

src/utils/timeUtils.jsx

@@ -160,6 +160,33 @@ const dayobsAtMidnight = (dt, format = "yyyy-LL-dd") => {
   return dt.minus({ minutes: 1 }).toFormat(format);
 };
 
+/**
+ * Validate start/end millis and convert to Luxon DateTime objects if valid.
+ * Otherwise return the provided fullTimeRange.
+ *
+ * @param {number} startMillis
+ * @param {number} endMillis
+ * @param {[DateTime, DateTime]} fullTimeRange
+ * @returns {[DateTime, DateTime]} start/end DateTimes
+ */
+function getValidTimeRange(startMillis, endMillis, fullTimeRange) {
+  if (
+    startMillis != null &&
+    endMillis != null &&
+    !Number.isNaN(startMillis) &&
+    !Number.isNaN(endMillis)
+  ) {
+    const [fullStart, fullEnd] = fullTimeRange;
+    if (
+      startMillis >= fullStart.toMillis() &&
+      endMillis <= fullEnd.toMillis()
+    ) {
+      return [millisToDateTime(startMillis), millisToDateTime(endMillis)];
+    }
+  }
+  return fullTimeRange;
+}
+
 export {
   isoToTAI,
   isoToUTC,
@@ -173,6 +200,7 @@ export {
   utcDateTimeStrToTAIMillis,
   utcDateTimeStrToMillis,
   dayobsAtMidnight,
+  getValidTimeRange,
   ISO_DATETIME_FORMAT,
   TAI_OFFSET_SECONDS,
 };

tests/timeUtils.test.js

@@ -14,6 +14,7 @@ import {
   utcDateTimeStrToTAIMillis,
   utcDateTimeStrToMillis,
   dayobsAtMidnight,
+  getValidTimeRange,
 } from "../src/utils/timeUtils";
 
 const TAI_OFFSET_SECONDS = 37;
@@ -114,4 +115,50 @@ describe("timeUtils", () => {
       expect(dayobsAtMidnight(dt, "yyyyLLdd")).toBe("20250817");
     });
   });
+
+  describe("getValidTimeRange", () => {
+    const fullTimeRange = [
+      getDayobsStartUTC("20250818"),
+      getDayobsEndUTC("20250818"),
+    ];
+
+    it("returns start/end DateTimes if millis are valid and in range", () => {
+      const startMillis =
+        getDayobsStartUTC("20250818").toMillis() + 6 * 3600 * 1000; // +6h
+      const endMillis =
+        getDayobsStartUTC("20250818").toMillis() + 18 * 3600 * 1000; // +18h
+
+      const result = getValidTimeRange(startMillis, endMillis, fullTimeRange);
+
+      expect(result[0].toMillis()).toBe(startMillis);
+      expect(result[1].toMillis()).toBe(endMillis);
+    });
+
+    it("returns fullTimeRange if startMillis is null", () => {
+      const endMillis = fullTimeRange[1].toMillis();
+      const result = getValidTimeRange(null, endMillis, fullTimeRange);
+      expect(result).toEqual(fullTimeRange);
+    });
+
+    it("returns fullTimeRange if endMillis is NaN", () => {
+      const startMillis = fullTimeRange[0].toMillis();
+      const result = getValidTimeRange(startMillis, NaN, fullTimeRange);
+      expect(result).toEqual(fullTimeRange);
+    });
+
+    it("returns fullTimeRange if times are out of range", () => {
+      const startMillis = fullTimeRange[0].toMillis() - 3600 * 1000; // before range
+      const endMillis = fullTimeRange[1].toMillis() + 3600 * 1000; // after range
+
+      const result = getValidTimeRange(startMillis, endMillis, fullTimeRange);
+      expect(result).toEqual(fullTimeRange);
+    });
+
+    it("returns fullTimeRange if times partially out of range", () => {
+      const startMillis = fullTimeRange[0].toMillis() + 2 * 3600 * 1000; // in range
+      const endMillis = fullTimeRange[1].toMillis() + 3600 * 1000; // out of range
+      const result = getValidTimeRange(startMillis, endMillis, fullTimeRange);
+      expect(result).toEqual(fullTimeRange);
+    });
+  });
 });