feat: add parse-header-link helper

packages/backend/src/helpers/parse-header-link.ts

@@ -0,0 +1,48 @@
+type TParameters = {
+  [key: string]: string;
+  rel?: string;
+};
+
+type TReference = {
+  uri: string;
+  parameters: TParameters;
+};
+
+type TRel = 'next' | 'prev' | 'first' | 'last';
+
+type TParsedLinkHeader = {
+  next?: TReference;
+  prev?: TReference;
+  first?: TReference;
+  last?: TReference;
+};
+
+export default function parseLinkHeader(link: string): TParsedLinkHeader {
+  const parsed: TParsedLinkHeader = {};
+
+  if (!link) return parsed;
+
+  const items = link.split(',');
+
+  for (const item of items) {
+    const [rawUriReference, ...rawLinkParameters] = item.split(';') as [string, ...string[]];
+    const trimmedUriReference = rawUriReference.trim();
+
+    const reference = trimmedUriReference.slice(1, -1);
+    const parameters: TParameters = {};
+
+    for (const rawParameter of rawLinkParameters) {
+      const trimmedRawParameter = rawParameter.trim();
+      const [key, value] = trimmedRawParameter.split('=');
+
+      parameters[key.trim()] = value.slice(1, -1);
+    }
+
+    parsed[parameters.rel as TRel] = {
+      uri: reference,
+      parameters,
+    };
+  }
+
+  return parsed;
+}