refactor(api): simplify 'years' endpoint

src/pages/api/v1/years/[year].json.ts

@@ -11,21 +11,21 @@ const quoteRecords = await getCollection("quoteRecords");
 const quoteDates = new Set(
   quoteRecords.flatMap((quoteRecord) => Object.keys(quoteRecord.data)),
 );
-const quoteYears = new Set(
+export const quoteYears = new Set(
   [...quoteDates].map((date) => new Date(date).getUTCFullYear()),
 );
 
-export const getStaticPaths = (() => {
-  const quotesByYearBySymbol = new Map(
-    quoteRecords.map((quoteRecord) => {
-      const quotes = Object.entries(quoteRecord.data);
-      return [
-        quoteRecord.id,
-        Map.groupBy(quotes, ([date]) => new Date(date).getUTCFullYear()),
-      ];
-    }),
-  );
+export const quotesByYearBySymbol = new Map(
+  quoteRecords.map((quoteRecord) => {
+    const quotes = Object.entries(quoteRecord.data);
+    return [
+      quoteRecord.id,
+      Map.groupBy(quotes, ([date]) => new Date(date).getUTCFullYear()),
+    ];
+  }),
+);
 
+export const getStaticPaths = (() => {
   return [...quoteYears].map((year) => ({
     params: { year: year.toString() },
     props: Object.fromEntries(

src/pages/api/v1/years/index.json.ts

@@ -1,26 +1,15 @@
 import type { APIRoute } from "astro";
-import { getCollection } from "astro:content";
 
-const quoteRecords = await getCollection("quoteRecords");
-
-const symbolsByYear = new Map<number, string[]>();
-for (const quoteRecord of quoteRecords) {
-  const years = [
-    ...new Set(
-      Object.keys(quoteRecord.data).map((date) =>
-        new Date(date).getUTCFullYear(),
-      ),
-    ),
-  ];
-  for (const year of years) {
-    let symbols = symbolsByYear.get(year);
-    if (symbols == null) {
-      symbols = [];
-      symbolsByYear.set(year, symbols);
-    }
-    symbols.push(quoteRecord.id);
-  }
-}
+import { quoteYears, quotesByYearBySymbol } from "./[year].json";
 
 export const GET: APIRoute = () =>
-  Response.json(Object.fromEntries(symbolsByYear));
+  Response.json(
+    Object.fromEntries(
+      [...quoteYears].map((year) => [
+        year,
+        [...quotesByYearBySymbol]
+          .filter(([, quotesByYear]) => quotesByYear.has(year))
+          .map(([symbol]) => symbol),
+      ]),
+    ),
+  );