Make computed gqlQueryArgs side-effect free again

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aleksis/apps/alsijil/frontend/components/coursebook/Coursebook.vue

@@ -105,6 +105,8 @@ export default {
       knownDates: {},
       docsByDay: {},
       lastQuery: null,
+      dateStart: "",
+      dateEnd: "",
       // Placeholder values while query isn't completed yet
       groups: [],
       courses: [],
@@ -116,13 +118,12 @@ export default {
     //            Resets date range.
     gqlQueryArgs() {
       console.log('computing gqlQueryArgs');
-      const dateRange = this.resetDate();
       return {
         own: this.filterType === "all" ? false : true,
         objId: this.objId ? Number(this.objId) : undefined,
         objType: this.objType?.toUpperCase(),
-        dateStart: dateRange[0].toISODate(),
-        dateEnd: dateRange[1].toISODate(),
+        dateStart: this.dateStart,
+        dateEnd: this.dateEnd,
         incomplete: !!this.incomplete,
       };
     },
@@ -154,6 +155,10 @@ export default {
             },
             hash: this.$route.hash,
           });
+          // computed should not have side effects
+          // but this was actually done before filters was refactored into
+          // its own component
+          this.resetDate();
         }
       },
     },
@@ -172,7 +177,8 @@ export default {
       dateRange.forEach((ts) => this.knownDates[ts] = true);
       const lastIdx = dateRange.length - 1;
       // Returning a dateRange each around first & last date for the initial query
-      return [this.dateRange(dateRange[0])[0], this.dateRange(dateRange[lastIdx])[lastIdx]];
+      this.dateStart = this.dateRange(dateRange[0])[0].toISODate();
+      this.dateEnd = this.dateRange(dateRange[lastIdx])[lastIdx].toISODate();
     },
     // => {dt: [dt doc ...] ...}
     groupDocsByDay(docs) {
@@ -326,7 +332,8 @@ export default {
       // scroll
     },
   },
-  mounted() {
+  created() {
+    this.resetDate();
     window.addEventListener('scroll', this.debounce(this.setCurrentDay, 300));
   },
 };