Introduction to AST's and Codemods

@chrislaughlin

What we will "learn"

What is an AST?
What are they used for?
Lets write a codemod
?????
Profit!

What is an AST?

const

foo

=

'bar'

;

Program/File

Variable Declaration

Identifier

Literal

Variable Declarator

What are they used for?

Codemods

https://astexplorer.net/#/gist/bf4110afdcb4e8f42da96f68cccebe60/0b394b55e7aebc4306e6034fb5398991ca8a8201

https://astexplorer.net/#/gist/1940713b5a1bf77abeaa530ab8f72b72/a4893174948de17283c530fac9f22740ed1f35d6

https://astexplorer.net/#/gist/cfb2ca69c30d954b39ae8d21fa329bf4/7541dec7a3b1de31f5ed1e48cb89d746785709ca

https://astexplorer.net/#/gist/0d6e1a273115e5f9e6c563c0edfcce52/c957328e59b8e0c17a7f4e8b49de318593c3aba0

Links

https://github.com/facebook/jscodeshift/blob/master/src/collections/Node.js

https://github.com/facebook/jscodeshift/blob/master/src/Collection.js

Introduction to AST's and Codemods

By Chris Laughlin

Introduction to AST's and Codemods

491

Chris Laughlin

chrislaughlin