chore: add case insensitive get header function (#373)

src/core.ts

@@ -1059,16 +1059,33 @@ export const isHeadersProtocol = (headers: any): headers is HeadersProtocol => {
  return typeof headers?.get === 'function';
 };
 
-export const getHeader = (headers: HeadersLike, key: string): string | null | undefined => {
- const lowerKey = key.toLowerCase();
- if (isHeadersProtocol(headers)) return headers.get(key) || headers.get(lowerKey);
- const value = headers[key] || headers[lowerKey];
- if (Array.isArray(value)) {
- if (value.length <= 1) return value[0];
- console.warn(`Received ${value.length} entries for the ${key} header, using the first entry.`);
- return value[0];
+export const getRequiredHeader = (headers: HeadersLike, header: string): string => {
+ const lowerCasedHeader = header.toLowerCase();
+ if (isHeadersProtocol(headers)) {
+ // to deal with the case where the header looks like Finch-Event-Id
+ const intercapsHeader =
+ header[0]?.toUpperCase() +
+ header.substring(1).replace(/([^\w])(\w)/g, (_m, g1, g2) => g1 + g2.toUpperCase());
+ for (const key of [header, lowerCasedHeader, header.toUpperCase(), intercapsHeader]) {
+ const value = headers.get(key);
+ if (value) {
+ return value;
+ }
+ }
  }
- return value;
+
+ for (const [key, value] of Object.entries(headers)) {
+ if (key.toLowerCase() === lowerCasedHeader) {
+ if (Array.isArray(value)) {
+ if (value.length <= 1) return value[0];
+ console.warn(`Received ${value.length} entries for the ${header} header, using the first entry.`);
+ return value[0];
+ }
+ return value;
+ }
+ }
+
+ throw new Error(`Could not find ${header} header`);
 };
 
 /**