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Function: mergeHeaders()

mergeHeaders(...maps): Record<string, string>

Defined in: src/core/transport.ts:121

Merge header maps case-insensitively; a later map's value wins.

Parameters​

maps​

...(Record<string, string> | undefined)[]

Header maps in increasing precedence; undefined entries are skipped.

Returns​

Record<string, string>

A new map. When two keys differ only in case the earlier key is dropped and the later key's spelling and value are kept.

Example​

import { mergeHeaders } from './core/transport.js'; // not re-exported from the package root

mergeHeaders({ 'user-agent': 'default' }, { 'User-Agent': 'mine' });
// { 'User-Agent': 'mine' }

Remarks​

The auth providers rely on the precedence: mergeHeaders(provider, req.headers) lets a header the caller set win over the provider's.