Add an optional 'customHeaders' field to AWSAppSyncClientOptions to easily add headers to requests

[babouinette]

Description of changes:

This change allows passing a customHeaders argument to AWSAppSyncClientOptions to easily add headers to requests, by using the 'headers' field in createHttpLink.

For example, to add an authorization header, instead of doing this :

const AppSyncConfig = {
  url:  "url",
  region: "us-east-1",
  auth: {
    type: "API_KEY",
    apiKey: "key"
  }
};

const client = new AWSAppSyncClient(AppSyncConfig, {
  link: createAppSyncLink({
    ...AppSyncConfig,
    resultsFetcherLink: ApolloLink.from([
      createHttpLink({
        uri: AppSyncConfig.url,
        headers: {"Authorization" : "Bearer 1234"},
      })
    ])
  })
});

We could do this :

const AppSyncConfig = {
  url: "url",
  region: "us-east-1",
  auth: {
    type: "API_KEY",
    apiKey: "key",
  },
  customHeaders: {"Authorization" : "Bearer 1234"},
};

const client = new AWSAppSyncClient(AppSyncConfig);

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[pickfire]

I rather not have this, in our case our custom header is not known until called.

[bpcrao]

I rather not have this, in our case our custom header is not known until called.

is there a better way to do this? like pass headers(tokens) only during mutate or query?
and I do not want to create client every time for every query too

[pickfire]

is there a better way to do this? like pass headers(tokens) only during mutate or query?
and I do not want to create client every time for every query too

For us, we only know it during the query, every query needs different header, maybe allow the query to be set during runtime?

[bpcrao]

client.mutate({ mutation: mutationName, context: {
headers:{ ....headersJSON} // custom headers
} })

why is this not helping you? it worked for me

[pickfire]

How did you do client.mutate? I don't have that function here. Note that I was using angular.

[bpcrao]

@pickfire using AWSAppSyncClient

[pickfire]

I don't use that directly. Also, I left the company working on this already.