serverless/lib/plugins/aws/package/compile/events/alexa-skill.js

import _ from 'lodash'
import resolveLambdaTarget from '../../../utils/resolve-lambda-target.js'

class AwsCompileAlexaSkillEvents {
  constructor(serverless) {
    this.serverless = serverless
    this.provider = this.serverless.getProvider('aws')

    this.serverless.configSchemaHandler.defineFunctionEvent(
      'aws',
      'alexaSkill',
      {
        anyOf: [
          { $ref: '#/definitions/awsAlexaEventToken' },
          {
            type: 'object',
            properties: {
              appId: { $ref: '#/definitions/awsAlexaEventToken' },
              enabled: { type: 'boolean' },
            },
            required: ['appId'],
            additionalProperties: false,
          },
        ],
      },
    )

    this.hooks = {
      initialize: () => {
        if (
          this.serverless.service.provider.name === 'aws' &&
          Object.values(this.serverless.service.functions).some(({ events }) =>
            events.some((event) => event === 'alexaSkill'),
          )
        ) {
          this.serverless._logDeprecation(
            'ALEXA_SKILL_EVENT_WITHOUT_APP_ID',
            'Starting with next major version, support for alexaSkill event without appId specified will be removed.',
          )
        }
      },
      'package:compileEvents': async () => this.compileAlexaSkillEvents(),
    }
  }

  compileAlexaSkillEvents() {
    this.serverless.service.getAllFunctions().forEach((functionName) => {
      const functionObj = this.serverless.service.getFunction(functionName)
      let alexaSkillNumberInFunction = 0

      functionObj.events.forEach((event) => {
        if (event.alexaSkill) {
          let enabled = true
          let appId
          if (typeof event.alexaSkill === 'string') {
            appId = event.alexaSkill
          } else {
            appId = event.alexaSkill.appId
            // Parameter `enabled` is optional, hence the explicit non-equal check for false.
            enabled = event.alexaSkill.enabled !== false
          }
          alexaSkillNumberInFunction++

          const permissionTemplate = {
            Type: 'AWS::Lambda::Permission',
            DependsOn: _.get(functionObj.targetAlias, 'logicalId'),
            Properties: {
              FunctionName: resolveLambdaTarget(functionName, functionObj),
              Action: enabled
                ? 'lambda:InvokeFunction'
                : 'lambda:DisableInvokeFunction',
              Principal: 'alexa-appkit.amazon.com',
            },
          }

          if (appId) {
            permissionTemplate.Properties.EventSourceToken = appId.replace(
              /\\n|\\r/g,
              '',
            )
          }

          const lambdaPermissionLogicalId =
            this.provider.naming.getLambdaAlexaSkillPermissionLogicalId(
              functionName,
              alexaSkillNumberInFunction,
            )

          const permissionCloudForamtionResource = {
            [lambdaPermissionLogicalId]: permissionTemplate,
          }

          _.merge(
            this.serverless.service.provider.compiledCloudFormationTemplate
              .Resources,
            permissionCloudForamtionResource,
          )
        }
      })
    })
  }
}

export default AwsCompileAlexaSkillEvents