From b07e0ac3501896ce18e1f96fc9442fdf359f1b12 Mon Sep 17 00:00:00 2001
From: Fabian Engelniederhammer <fabian.engelniederhammer@tngtech.com>
Date: Fri, 19 Jul 2024 12:01:23 +0200
Subject: [PATCH] refactor(components): improve types of `getMinMaxTemporal`

If the input values are narrowed to a specific version of `Temporal`,
the result will also be typed to that specific version.
---
 components/src/query/queryRelativeGrowthAdvantage.ts | 6 ++----
 components/src/utils/temporal.ts                     | 6 +++---
 2 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/components/src/query/queryRelativeGrowthAdvantage.ts b/components/src/query/queryRelativeGrowthAdvantage.ts
index f93623a6..558fcadb 100644
--- a/components/src/query/queryRelativeGrowthAdvantage.ts
+++ b/components/src/query/queryRelativeGrowthAdvantage.ts
@@ -28,12 +28,10 @@ export async function queryRelativeGrowthAdvantage<LapisDateField extends string
         mapNumerator.evaluate(lapis, signal),
         mapDenominator.evaluate(lapis, signal),
     ]);
-    const { min, max } = getMinMaxTemporal(denominatorData.content.map((d) => d.date));
-    if (!min && !max) {
+    const { min: minDate, max: maxDate } = getMinMaxTemporal(denominatorData.content.map((d) => d.date));
+    if (!minDate && !maxDate) {
         return null;
     }
-    const minDate = min as YearMonthDay;
-    const maxDate = max as YearMonthDay;
 
     const numeratorCounts = new Map<YearMonthDay, number>();
     numeratorData.content.forEach((d) => {
diff --git a/components/src/utils/temporal.ts b/components/src/utils/temporal.ts
index b920bdb5..0810fee4 100644
--- a/components/src/utils/temporal.ts
+++ b/components/src/utils/temporal.ts
@@ -345,9 +345,9 @@ export function compareTemporal(a: Temporal | null, b: Temporal | null): number
     return 0;
 }
 
-export function getMinMaxTemporal(values: Iterable<Temporal | null>) {
-    let min = null;
-    let max = null;
+export function getMinMaxTemporal<T extends Temporal>(values: Iterable<T | null>) {
+    let min: T | null = null;
+    let max: T | null = null;
     for (const value of values) {
         if (value === null) {
             continue;