pambda

Pluggable Lambda for AWS.

Usage

By using this package, you can define a Lambda handler in function synthesis as follows:

const { compose, createLambda } = require('pambda');

exports.handler = createLambda(
  compose(
    pambda1,
    pambda2,
    ...
  )
);

Definition

Pambda

type Pambda = (next: Lambda) => Lambda

This function returns Lambda. It specifies the Lambda that Lambda should call next by argument next.

Since next can specify Lambda to be executed next, one large Lambda can be divided into multiple smaller Lambdas.

Lambda

type Lambda = (event, context, callback) | (event, context) => Promise

Lambda supports both callback style functions and async functions.

When invoking Lambda in Pambda, it is necessary to make it work in both types of functions.

API

compose(...pambdas: Pambda[]): Pambda

Return a Pambda which synthesized specified Pambdas.

If you pass the last executed Lambda to the synthesized Pambda, the Lambda of the Pambda specified by the first argument is returned. By executing that Lambda, Lambda in Pambda is executed in the order specified by the arguments.

If there is an identity pambda in the argument pambdas, they are not to be composited.

Falsy values ​​are also ignored. This is useful that a process depending on environment variables such as a following:

compose(
  process.env.AWS_SAM_LOCAL === 'true' && localOnlyPambda,

  ...
)

createLambda(pambda: Pambda): Lambda

Return Lambda from the specified Pambda. The Lambda is exported and used as the main handler.

Pambda's argument next is passed Lambda which returns an error.

This function passes lambda-terminator to argument next in the passed pambda.

The execution of lambda-terminator means there is a bug in the pambda.

identity: Pambda

This pambda do nothing.

Context Extending

Some pambdas add properties into a context. Adding properties are following:

Property	Pambda
[AWSService]	pambda-aws
logEvent	pambda-cwlogs
redirect	pambda-redirect
render	pambda-pug

Event Extending

Property	Pambda
cookies	pambda-cookie

Related

• create-pambda-app
• pambda-404
• pambda-aws
• pambda-binary-support
• pambda-by-env
• pambda-cache
• pambda-cookie
• pambda-cwlogs
• pambda-env
• pambda-errorhandler
• pambda-github-fetch
• pambda-headers
• pambda-json-api
• pambda-jwt-authorizer
• pambda-logger
• pambda-path
• pambda-pug
• pambda-records
• pambda-redirect
• pambda-redux
• pambda-router
• pambda-s3-fetch
• pambda-serve-static
• pambda-tap
• pambda-terminator

License

MIT