(AppSync) additionalAuthenticationProviders seems to be a required parameter

[asnaseer-resilient]

I used to be able to deploy my AppSync stack with this relevant code snippet using CDK v1.39.0:

    const graphQlApi = new cdkAppsync.GraphQLApi(this, 'GraphQL', {
      name: CDK_UTILS.resourceName('app-sync-graphql-api'),
      schemaDefinitionFile: 'schema.graphql',
      authorizationConfig: {
        defaultAuthorization: {
          userPool,
          defaultAction: cdkAppsync.UserPoolDefaultAction.ALLOW
        }
      }
    });

When upgrading to v1.46.0, I changed the above snippet to:

    const graphQlApi = new cdkAppsync.GraphQLApi(this, 'GraphQL', {
      name: CDK_UTILS.resourceName('app-sync-graphql-api'),
      schemaDefinitionFile: 'schema.graphql',
      authorizationConfig: {
        defaultAuthorization: {
          // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-member-access
          authorizationType: cdkAppsync.AuthorizationType.USER_POOL,
          userPoolConfig: {
            userPool,
            defaultAction: cdkAppsync.UserPoolDefaultAction.ALLOW
          }
        }
      }
    });

NOTE: I had to add an eslint comment on the assignment of authorizationType as it was complaining about this.

I then received this error on deployment:

.../node_modules/@aws-cdk/aws-appsync/lib/graphqlapi.js:100
            additionalAuthenticationProviders: ((_g = props.authorizationConfig) === null || _g === void 0 ? void 0 : _g.additionalAuthorizationModes.length) ? this.formatAdditionalAuthorizationModes(props.authorizationConfig.additionalAuthorizationModes)
                                                                                                                                                      ^
TypeError: Cannot read property 'length' of undefined
    at new GraphQLApi (.../node_modules/@aws-cdk/aws-appsync/lib/graphqlapi.js:100:151)
    at new AppSyncConstruct (.../app-sync/app-sync-construct.js:36:28)

From the error I am guessing that the implementation assumes that additionalAuthenticationProviders parameters is always specified so I changed the above code to this:

    const graphQlApi = new cdkAppsync.GraphQLApi(this, 'GraphQL', {
      name: CDK_UTILS.resourceName('app-sync-graphql-api'),
      schemaDefinitionFile: 'schema.graphql',
      authorizationConfig: {
        defaultAuthorization: {
          // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-member-access
          authorizationType: cdkAppsync.AuthorizationType.USER_POOL,
          userPoolConfig: {
            userPool,
            defaultAction: cdkAppsync.UserPoolDefaultAction.ALLOW
          }
        },
        additionalAuthorizationModes: []     // <--- workaround here
      }
    });

This got rid of the error but I believe we should not have to specify an empty array and am therefore raising this as a bug.

My deployments are run via CircleCI but I see the same error even when deploying locally (Mac OS Catalina 10.15.5 with Node 12.14.0) using a command like this:

cdk deploy appSync --app .build/stacks/cfd-api-stacks.js -o .build/cdk.out/appSync --no-staging --exclusively --require-approval never

Environment

• CLI Version : 1.46.0
• Node.js Version: circleci/node:12.14.1
• OS : CircleCI node_executor
• Language (Version): TypeScript 3.9.5, eslint 7.2.0

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This is 🐛 Bug Report

[civilizeddev]

duplicate of #8666

[MrArnoldPalmer]

Resolved via #8673