v5 migration codemod

Question

v5 migration codemod

with-heart opened this issue a year ago · comments

This issue is for building a codemod that migrates a codebase from v4 to v5. The codemod would analyze the abstract syntax tree (AST) of the codebase in order to identify syntax changes that need to be made and apply those changes.

We'd also need to create a cli to apply the codemod. I can't remember if there's an xstate cli out there already or not, but if so we can reuse it. I'm thinking xstate codemod v4-to-v5 or something like that.

You can find the current (as of 4/14) migration guide here: https://docs-git-davidkpiano-v5-outline-statelyai.vercel.app/xstate-v5/migration

Here's a table of changes to target:

v4	v5	Changes to make	Comments/Questions
`Machine`	`createMachine`	replace `Machine` identifier with `createMachine` replace `Machine` import with `createMachine`
`cond`	`guard`	replace `cond` keys with `guard`
`cond` and `actions` objects can have any key	objects can only have `type` and `params`	move any non-`type` properties into new `params` property object
`(context, event)`	`({context, event})`	wrap arguments in object syntax	if the arguments aren't named `context` and `event`, we'll need to make sure that the object's keys use the correct names (example: `(ctx)` becomes `({context: ctx})`)
`actor.onTransition`	`actor.subscribe`	?	do they have the same interface?
`send`	`raise`/`sendTo`	?	is there a way to tell from `send` usage which new fn should be used instead?
`internal: false`	`reenter: true`	if `internal: true`, remove property if `internal: false`, remove and replace with new `reenter: true` property
`interpret(machine).start(state)`	`interpret(machine, {state}).start()`	remove `state` argument from `start` call create/update 2nd `interpret` argument object with `state` property
`actor.send('event')`	`actor.send({type: 'event'})`	remove string argument create object argument with `type: 'event'` property
null event (`''`)	`always`	replace `''` key with `always`
`createMachine(config, options)`	`createMachine(config).provide(options)`	remove 2nd argument from `createMachine` append call to `.provide` with `options` as its argument
`machine.withConfig(options, context)`	`machine.provide({…options, context})`	remove `.withConfig` call add `.provide` call if `context` is passed add empty object argument to `provide` call spread `options` in object argument add `context` property to object argument if `context` is not passed, add `options` as argument to `provide`	need to handle cases where both `.withConfig` and `.withContext` were called
`machine.withContext(context)`	`machine.provide({context})`	remove `.withContext` call add `.provide` call add object with `context` property as argument to `provide`	need to handle cases where both `.withConfig` and `.withContext` were called
`predictableActionArguments: true`	-	remove `predictableActionArguments` property
`strict: true`	-	remove `strict` property
`state.history`	-	remove `state.history` property	is there anything else we could do here? maybe notify the user that `state.history` no longer exists and where it's being used so they can adjust their code?
`actor.batch([...])`	removed	remove `actor.batch` call create an individual `actor.send` call for each event in the array	is this an appropriate solution?
`config.schema`	`config.types`	rename `schema` key to `types`	need to make sure this works together with `config.tsTypes` change
`config.tsTypes`	`config.types.typegen`	create `types` property with empty object value move `tsTypes` property to `types` object rename `tsTypes` key to `typegen`	need to make sure this works together with `config.schema` change