apollo-server-plugin-http-headers

Allows you to set HTTP Headers and Cookies easily in your resolvers. This is especially useful in apollo-server-lambda, because you don't have any other options there to set headers or cookies.

The way it works is simple: you put an array for cookies and an array for headers in your context; you can then access them in your resolvers (and therefore add, alter or delete headers and cookies). Before your request is sent to the client this plugin loops through the arrays and adds every item to the HTTP response. The logic is very easy, actually the documentation is way longer than the source code.

Installation

$3

npm install apollo-server-plugin-http-headers

$3

Import and register the plugin, then add setHeaders and setCookies to context:

``javascript
const httpHeadersPlugin = require("apollo-server-plugin-http-headers");

const server = new ApolloServer({
typeDefs,
resolvers,
plugins: [httpHeadersPlugin],
context: {
setCookies: new Array(),
setHeaders: new Array()
}
});
`

Please note: The context argument varies depending on the specific integration (e.g. Express, Koa, Lambda, etc.) being used. See the official apollo-server documentation for more details.
Example for the Lambda integration (apollo-server-lambda):

`javascript
const httpHeadersPlugin = require("apollo-server-plugin-http-headers");

const server = new ApolloServer({
typeDefs,
resolvers,
plugins: [httpHeadersPlugin],
context: ({ event, context }) => {
return {
event,
context,
setCookies: new Array(),
setHeaders: new Array()
};
}
});
`

Usage

$3

Set a header in a resolver:

`javascript
context.setHeaders.push({ key: "headername", value: "headercontent" });
`

Complete example:

`javascript
const resolvers = {
Query: {
hello: async (parent, args, context, info) => {
context.setHeaders.push({ key: "X-TEST-ONE", value: "abc" });
context.setHeaders.push({ key: "X-TEST-TWO", value: "def" });
return "Hello world!";
}
}
};
`

$3

Set a cookie in a resolver:

`javascript
context.setCookies.push({
name: "cookieName",
value: "cookieContent",
options: {
domain: "example.com",
expires: new Date("2021-01-01T00:00:00"),
httpOnly: true,
maxAge: 3600,
path: "/",
sameSite: true,
secure: true
}
});
`

Complete example:

`javascript
const resolvers = {
Query: {
hello: async (parent, args, context, info) => {

context.setCookies.push({
name: "cookieName",
value: "cookieContent",
options: {
domain: "example.com",
expires: new Date("2021-01-01T00:00:00"),
httpOnly: true,
maxAge: 3600,
path: "/",
sameSite: true,
secure: true
}
});

return "Hello world!";
}
}
};
`

#### Cookie Options

This package uses jshttp/cookie for serializing cookies and you can use all the options they provide. Find an overview below or the complete documentation here.

option | description
--- | ---
domain | Specifies the value for the Domain Set-Cookie attribute. By default, no domain is set.
encode | Specifies a function that will be used to encode a cookie's value. Default: encodeURIComponent
expires | Specifies the Date object to be the value for the Expires Set-Cookie attribute. If expires and maxAge are set, maxAge mostly wins on the client side. By default, no expiration is set.
httpOnly | Specifies the boolean value for the HttpOnly Set-Cookie attribute. Defaults to false.
maxAge | Specifies the number (in seconds) to be the value for the Max-Age Set-Cookie attribute. By default, no maximum age is set.
path | Specifies the value for the Path Set-Cookie attribute. By default, no path is set and the user agent computes a path according to these algorithms.
sameSite | Specifies the boolean or string to be the value for the SameSite Set-Cookie attribute. Valid values: true, false, 'lax', 'none' and 'strict'.
secure | Specifies the boolean value for the Secure Set-Cookie attribute.By default, the Secure` attribute is not set.

Limitations

$3

There is at the moment no possility to set multiple cookies because apollo server does not support that. Find details and workaround inspiration here.
If you add multiple items to setCookie I'll throw an exception at your face (-;