AppSync Butler (SST)

AppSync Butler is an AppSync (GraphQL) API development framework, compatible with AWS Cloud Development Kit and Serverless Stack Toolkit. Visit the homepage for more information.

This package is concerned with loading on-disk resolvers into SST AppSync API constructs. This is not necessarily required when using SST, you can still load on-disk resolvers and functions using @appsync-butler/core only:

import { Loader } from '@appsync-butler/core';
import { StackContext, AppSyncApi, Table } from '@serverless-stack/resources';

export function MyStack({ stack }: StackContext) {
	const table = new Table(stack, 'table', {
		fields: { pk: "string" },
		primaryIndex: { partitionKey: "pk" }
	});
	const api = new AppSyncApi(stack, 'api', {
		schema: 'graphql/index.graphql',
		dataSources: {
			sstTableDs: { type: "dynamodb", table }
		}
	});
    
	const loader = new Loader(stack, {
		api: api.cdk.graphqlApi,
		dataSources: {
			tableDs: getDataSource(api, 'sstTableDs')!
		},
		defaultUnitResolverDataSource: 'tableDs',
		defaultFunctionDataSource: 'tableDs'
	});
	loader.load();
}

function getDataSource(api: AppSyncApi, key: string) {
	const ds = api.getDataSource(key);
	if (! ds) {
		throw new Error(
			`Expecting '${key}' datasource key to be set, ` +
			'found otherwise.'
		)
	}
	return ds;
}

This package introduces SstLoader to load resolvers with SST compatibility. This might be useful for specific use cases.

import { StackContext, AppSyncApi, Table } from '@serverless-stack/resources';
import { SstLoader } from '@appsync-butler/sst';
import { Resolver } from '@aws-cdk/aws-appsync-alpha';

export function MyStack({ stack }: StackContext) {
    const table = new Table(stack, 'table', { ... });
    const api = new AppSyncApi(stack, 'api', {
        schema: 'graphql/index.graphql',
        dataSources: {
            tableDs: { type: "dynamodb", table }
        }
    });

    const loader = new SstLoader(stack, {
        api,
        defaultUnitResolverDataSource: 'tableDs',
        defaultFunctionDataSource: 'tableDs'
    });
    loader.load();

    // Suppose we have the following on-disk resolver:
    // vtl/resolvers/Query/posts

    const r = api.getResolver('Query posts');
    r instanceof Resolver // => true
}

Documentation

Explore the documentation of AppSync Butler here.