Implement lambda BatchInvoke

packages/appsync-emulator-serverless/__test__/example/handler.js

@@ -3,6 +3,18 @@ module.exports.graphqlJSON = (event, context, callback) =>
     test: 'yup',
   });
 
+module.exports.graphqlArrayJSON = (event, context, callback) =>
+  callback(null, [{ test: 'yup.0' }, { test: 'yup.1' }]);
+
+module.exports.graphqlBatchJSON = (events, context, callback) =>
+  callback(
+    null,
+    events.map(e => [
+      { test: `${e.source.test}.0` },
+      { test: `${e.source.test}.1` },
+    ]),
+  );
+
 module.exports.graphql = (event, context, callback) => {
   const field = Object.keys(event.arguments)[0];
   return callback(null, event.arguments[field]);

packages/appsync-emulator-serverless/__test__/example/mapping-templates/lambda-batch-request.vtl

@@ -0,0 +1,8 @@
+{
+    "version": "2017-02-28",
+    "operation": "BatchInvoke",
+    "payload": {
+        "arguments":  $utils.toJson($context.arguments),
+        "source":  $utils.toJson($context.source)
+    }
+}

packages/appsync-emulator-serverless/__test__/example/schema.graphql

@@ -11,6 +11,7 @@ type Query {
   QuoteResponse(query: [AttributeFilter]): [QuoteResponse]!
   cognitoInfo: CognitoInfo!
   lambda: LambdaInfo!
+  lambdaBatch: [LambdaInfo]
   lambdaPython: LambdaInfo!
   lambdaRuby: LambdaInfo!
   lambdaGo: LambdaInfo!
@@ -77,6 +78,7 @@ type CognitoInfo {
 
 type LambdaInfo {
   test: String!
+  lambdaChild: [LambdaInfo]
 }
 
 type QuoteRequest {

packages/appsync-emulator-serverless/__test__/example/serverless.yml

@@ -122,6 +122,16 @@ custom:
         type: Query
         request: lambda-request.vtl
         response: result-response.txt
+      - dataSource: TestLambdasJSON
+        type: Query
+        field: lambdaBatch
+        request: lambda-request.vtl
+        response: result-response.txt
+      - dataSource: TestBatchLambdaJSON
+        type: LambdaInfo
+        field: lambdaChild
+        request: lambda-batch-request.vtl
+        response: result-response.txt
       - dataSource: TestLambdaJSON
         type: Query
         field: jsonTest
@@ -205,6 +215,20 @@ custom:
           lambdaFunctionArn: { Fn::GetAtt: [GraphqlLambdaFunction, Arn] }
           serviceRoleArn: { Fn::GetAtt: [AppSyncLambdaServiceRole, Arn] }
           functionName: graphqlJSON
+      - type: AWS_LAMBDA
+        name: TestLambdasJSON
+        description: 'Lambda JSON array DataSource'
+        config:
+          lambdaFunctionArn: { Fn::GetAtt: [GraphqlLambdasFunction, Arn] }
+          serviceRoleArn: { Fn::GetAtt: [AppSyncLambdaServiceRole, Arn] }
+          functionName: graphqlArrayJSON
+      - type: AWS_LAMBDA
+        name: TestBatchLambdaJSON
+        description: 'Lambda JSON DataSource'
+        config:
+          lambdaFunctionArn: { Fn::GetAtt: [GraphqlLambdaFunction, Arn] }
+          serviceRoleArn: { Fn::GetAtt: [AppSyncLambdaServiceRole, Arn] }
+          functionName: graphqlBatchJSON
       - type: HTTP
         name: TestHTTP
         description: 'Test HTTP endpoint'
@@ -234,6 +258,10 @@ custom:
 functions:
   graphqlJSON:
     handler: handler.graphqlJSON
+  graphqlArrayJSON:
+    handler: handler.graphqlArrayJSON
+  graphqlBatchJSON:
+    handler: handler.graphqlBatchJSON
   graphql:
     handler: handler.graphql
   emptyJSON:

packages/appsync-emulator-serverless/__test__/schemaTest.test.js

@@ -223,6 +223,59 @@ describe('creates executable schema', () => {
     expect(result).toMatchObject({ data: { lambda: { test: 'yup' } } });
   });
 
+  it('should allow querying lambda in batch', async () => {
+    const result = await graphql({
+      schema,
+      contextValue,
+      source: `
+      query test {
+        lambdaBatch {
+          test
+          lambdaChild {
+            test
+            lambdaChild {
+              test
+            }
+          }
+        }
+      }
+      `,
+    });
+
+    expect(result).toMatchObject({
+      data: {
+        lambdaBatch: [
+          {
+            test: 'yup.0',
+            lambdaChild: [
+              {
+                test: 'yup.0.0',
+                lambdaChild: [{ test: 'yup.0.0.0' }, { test: 'yup.0.0.1' }],
+              },
+              {
+                test: 'yup.0.1',
+                lambdaChild: [{ test: 'yup.0.1.0' }, { test: 'yup.0.1.1' }],
+              },
+            ],
+          },
+          {
+            test: 'yup.1',
+            lambdaChild: [
+              {
+                test: 'yup.1.0',
+                lambdaChild: [{ test: 'yup.1.0.0' }, { test: 'yup.1.0.1' }],
+              },
+              {
+                test: 'yup.1.1',
+                lambdaChild: [{ test: 'yup.1.1.0' }, { test: 'yup.1.1.1' }],
+              },
+            ],
+          },
+        ],
+      },
+    });
+  });
+
   it('should allow querying lambda python', async () => {
     const result = await graphql({
       schema,

packages/appsync-emulator-serverless/package.json

@@ -14,6 +14,7 @@
     "aws-sdk": "^2.254.1",
     "consola": "^1.4.1",
     "cors": "^2.8.4",
+    "dataloader": "^1.4.0",
     "dateformat": "^3.0.3",
     "event-to-promise": "^0.8.0",
     "express": "^4.16.3",

packages/appsync-emulator-serverless/schema.js

@@ -16,6 +16,7 @@ const log = require('logdown')('appsync-emulator:schema');
 const consola = require('./log');
 const { inspect } = require('util');
 const { scalars } = require('./schemaWrapper');
+const DataLoader = require('dataloader');
 
 const vtlMacros = {
   console: (...args) => {
@@ -187,31 +188,58 @@ const dispatchRequestToSource = async (
   }
 };
 
+const generateDataLoaderResolver = (source, configs) => {
+  const batchLoaders = {};
+  return fieldPath => {
+    if (batchLoaders[fieldPath] === undefined) {
+      batchLoaders[fieldPath] = new DataLoader(
+        requests => {
+          const batchRequest = requests[0];
+          batchRequest.payload = requests.map(r => r.payload);
+          consola.info(
+            'Rendered Batch Request:\n',
+            inspect(batchRequest, { depth: null, colors: true }),
+          );
+          log.info('resolver batch request', batchRequest);
+          return dispatchRequestToSource(source, configs, batchRequest);
+        },
+        {
+          shouldCache: false,
+        },
+      );
+    }
+
+    return batchLoaders[fieldPath];
+  };
+};
+
 const generateTypeResolver = (
   source,
   configs,
-  { requestPath, responsePath },
+  { requestPath, responsePath, dataLoaderResolver },
 ) => async (root, vars, context, info) => {
   try {
-    consola.start(
-      `Resolve: ${info.parentType}.${info.fieldName} [${gqlPathAsArray(
-        info.path,
-      )}]`,
-    );
-    log.info('resolving', gqlPathAsArray(info.path));
+    const fieldPath = `${info.parentType}.${info.fieldName}`;
+    const pathInfo = gqlPathAsArray(info.path);
+    consola.start(`Resolve: ${fieldPath} [${pathInfo}]`);
+    log.info('resolving', pathInfo);
+
     assert(context && context.jwt, 'must have context.jwt');
     const resolverArgs = { root, vars, context, info };
     const request = runRequestVTL(requestPath, resolverArgs);
-    consola.info(
-      'Rendered Request:\n',
-      inspect(request, { depth: null, colors: true }),
-    );
-    log.info('resolver request', request);
-    const requestResult = await dispatchRequestToSource(
-      source,
-      configs,
-      request,
-    );
+
+    let requestResult;
+    if (request.operation === 'BatchInvoke') {
+      const loader = dataLoaderResolver(fieldPath);
+      requestResult = await loader.load(request);
+    } else {
+      consola.info(
+        'Rendered Request:\n',
+        inspect(request, { depth: null, colors: true }),
+      );
+      log.info('resolver request', request);
+      requestResult = await dispatchRequestToSource(source, configs, request);
+    }
 
     const response = runResponseVTL(responsePath, resolverArgs, requestResult);
     consola.info(
@@ -308,6 +336,7 @@ const generateResolvers = (cwd, config, configs) => {
       const source = dataSourceByName[dataSource];
       const pathing = {
         requestPath: path.join(mappingTemplates, request),
+        dataLoaderResolver: generateDataLoaderResolver(source, configs),
         responsePath: path.join(mappingTemplates, response),
       };
       const resolver =

yarn.lock

@@ -1578,6 +1578,11 @@ data-urls@^1.0.0:
     whatwg-mimetype "^2.2.0"
     whatwg-url "^7.0.0"
 
+dataloader@^1.4.0:
+  version "1.4.0"
+  resolved "https://registry.yarnpkg.com/dataloader/-/dataloader-1.4.0.tgz#bca11d867f5d3f1b9ed9f737bd15970c65dff5c8"
+  integrity sha512-68s5jYdlvasItOJnCuI2Q9s4q98g0pCyL3HrcKJu8KNugUl8ahgmZYg38ysLTgQjjXX3H8CJLkAvWrclWfcalw==
+
 dateformat@^3.0.3:
   version "3.0.3"
   resolved "https://registry.yarnpkg.com/dateformat/-/dateformat-3.0.3.tgz#a6e37499a4d9a9cf85ef5872044d62901c9889ae"
@@ -4337,6 +4342,7 @@ lodash@^4.0.0, lodash@^4.11.1, lodash@^4.13.1, lodash@^4.17.10, lodash@^4.17.4,
 lodash@^4.17.11:
   version "4.17.11"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.11.tgz#b39ea6229ef607ecd89e2c8df12536891cac9b8d"
+  integrity sha512-cQKh8igo5QUhZ7lg38DYWAxMvjSAKG0A8wGSVimP07SIUEK2UO+arSRKbRZWtelMtN5V0Hkwh5ryOto/SshYIg==
 
 logdown@^3.2.3:
   version "3.2.3"