http-header-normalizer
This middleware normalizes HTTP header names to their canonical format. Very useful if clients are
not using the canonical names of header (e.g. content-type
as opposed to Content-Type
).
API Gateway does not perform any normalization, so the headers are propagated to Lambda exactly as they were sent by the client.
Other middlewares like jsonBodyParser
or urlEncodeBodyParser
will rely on headers to be in the canonical format, so if you want to support non-normalized headers in your
app you have to use this middleware before those ones.
This middleware will copy the original headers in event.rawHeaders
.
Install
To install this middleware you can use NPM:
- npm
- Yarn
npm install --save @middy/http-header-normalizer
yarn add @middy/http-header-normalizer
Options
normalizeHeaderKey
(function) (optional): a function that accepts an header name as a parameter and returns its canonical representation.canonical
(bool) (optional): if true, modifies the headers to canonical format, otherwise the headers are normalized to lowercase (defaultfalse
)
Sample usage
import middy from '@middy/core'
import httpHeaderNormalizer from '@middy/http-header-normalizer'
const handler = middy((event, context) => {
return {}
})
handler
.use(httpHeaderNormalizer())