Merge pull request #3513 from owid/detect-country-cache

enhance(util): cache `/detect-country` fetch

packages/@ourworldindata/utils/src/Util.ts

@@ -569,14 +569,19 @@ export const fetchText = async (url: string): Promise<string> => {
     })
 }
 
-export const getUserCountryInformation = async (): Promise<
+const _getUserCountryInformation = async (): Promise<
     UserCountryInformation | undefined
 > =>
     await fetch("/detect-country")
         .then((res) => res.json())
         .then((res) => res.country)
         .catch(() => undefined)
 
+// Memoized because this will pretty much never change during a session.
+// The memoization, however, also means that any failures will also be cached.
+// This is okay currently, because currently this information is very much an optional nice-to-have.
+export const getUserCountryInformation = memoize(_getUserCountryInformation)
+
 export const stripHTML = (html: string): string => striptags(html)
 
 // Math.rand doesn't have between nor seed. Lodash's Random doesn't take a seed, making it bad for testing.