Inject custom headers to express graphql

Hey everyone,

I’d like to know how to inject headers when using express graphql. The problem is, if I use multiple instances like this, importing modules to work as a SPA every single header coming from the module get overwritten by the first module I import:

app.use('/route1/graphql', expressGraphQL({
    schema: firstSchema,
    graphiql: (process.env.NODE_ENV === 'local' || process.env.NODE_ENV === 'development'),
    formatError: e => AccelerateErrorHandler(e, 'an error')
}));

app.use('/route2/graphql', expressGraphQL({
    schema: secondSchema,
    graphiql: (process.env.NODE_ENV === 'local' || process.env.NODE_ENV === 'development'),
    formatError: e => AccelerateErrorHandler(e, 'an error')
}));

So, is there a way to inject headers directly as params in the expressGraphQL function?

app.use('/route1/graphql', expressGraphQL({
    schema: secondSchema,
    headers (?)...
    graphiql: (process.env.NODE_ENV === 'local' || process.env.NODE_ENV === 'development'),
    formatError: e => AccelerateErrorHandler(e, 'an error')
}));

Thanks.

[acao]

good question! because you are reusing the same express routes each time to instantiate each middleware, the middlewares will overwrite eachother, so in this example only the third schema will be executable. you may want to read the docs to express app.use(). do you want to combine schemas?

as far as adding headers in express, you can do this via a middleware that uses res.headers.set(). make sure this middleware is added before graphql express middleware, as the latter is a terminating middleware and thus it sends response, any middlewares after it will not be executed

[acao]

I’m sorry but it just doesn’t look like you can override inbound request headers, and i’m still not really sure why. if graphql-express had a headers option it would be for setting response headers, not overriding the inbound request headers.

Maybe you’ll find some answers from the express community: https://gitter.im/expressjs/express