How to migrate from JavaScript to TypeScript

[clstokes]

If I start a Pulumi project as JavaScript, how can I switch to TypeScript without re-creating my resources.

[clstokes]

A Pulumi project can be converted from JavaScript to TypeScript with the steps below. This allows you to migrate without having to re-create stacks or resources.

Steps

1. Update your package.json for TypeScript:
   1. Remove the main: "index.js" (or similar) definition.
   2. Add @types/node to your devDependencies - e.g. npm i @types/[email protected] --save-dev.
2. Add a TSConfig file (tsconfig.json) to your project.
3. Rename your *.js files to *.ts and make any necessary import/require changes.

Once you complete this, your next pulumi pre will execute as TypeScript rather than JavaScript. You should not see any actual resources changes with the exception of using Pulumi's inline serverless function support - e.g. bucket.onObjectCreated(...). The serverless function itself (e.g. aws:lambda:Function) will be updated during your next deployment since the inline function will be compiled using the TypeScript compiler.

Helper script for steps 1 and 2

The below shell commands will help with steps 1 and 2 above using jq:

jq '.devDependencies += {"@types/node": "^10.0.0"} | . |= del(.main)' package.json > package.json.new && mv package.json.new package.json

curl -o tsconfig.json https://raw.githubusercontent.com/pulumi/templates/master/aws-typescript/tsconfig.json