Add codemod for v1 to v2 migration

[kkemple]

It would make upgrading much easier if users could run a codemod to convert any breaking changes programatically.

Some things to consider/questions to be answered:

• seems like this could be a plugin and use existing Gatsby APIs to figure out necessary changes
• would need to convert layout queries to static queries
• ???

[m-allanson]

I love codemods, it's like having magic wizards in my computer. It might not be practical to have codemods for every change, but the more the better.

I'd guess the codemod writing process would be:

• manually upgrade some sites to v2
• use that experience to write upgrading to v2 doc
• pick out parts from that doc that can be automated and write codemods for them
• update upgrade doc with codemod details
• upgrade more sites
• write more codemods
• etc etc

[kkemple]

Seems facebook is working on a nice interactive version of codemod
https://github.com/facebookincubator/fastmod

[rdela]

I started my site on canary branch based on Kyle’s tweet/branch, so maybe in good spot to diff with starter-blog and make that upgrading to v2 doc?

https://github.com/rdela/rdela.com

https://github.com/KyleAMathews/blog/tree/gatsby-v2-canary?files=1

https://github.com/KyleAMathews/blog/pull/21/files

https://twitter.com/kylemathews/status/954905518874664960?s=20

[rdela]

Inspiring prior art https://svelte.technology/blog/version-2

[rdela]

Everything from here down in this PR seems relevant
#4887 (comment)
Relevant parts start earlier:
#4887 (comment)

[rdela]

Particularly this PR where Kyle updates his blog
https://github.com/KyleAMathews/blog/pull/21/files

I remember the boundActionCreators => actions step, that seems ripe for codemod
rdela/rdela.com@0042e19#diff-fda05457e393bada716f508859bfc604

Need to dig into both of those PRs more; unsure currently about how <StaticQuery> changes will play out for codemod: whether that ends up being a suggestion codemod could make or item in aforementioned upgrading to v2 doc

[m-allanson]

Taking a look through the migration guide, things it might possible to codemod are:

• change navigateTo to navigate See feat: add a navigateTo -> navigate codemod #7532
• import link from gatsby See import link codemod #7806
• rename boundactioncreators to actions See Codmod to rename boundActionCreators to actions #7955
• use query in place of rootquery

[tsriram]

I'll give import link from gatsby codemod a try this weekend

[tsriram]

Doing another - rename boundActionCreators to actions

[DSchau]

@tsriram that would be great :) I'm not even 100% sure if you get file name, but if you do, you may want to restrict it to only certain files where that's valid. But looking forward to it!

[pieh]

@DSchau It's already opened - #7955 :)

[DSchau]

@pieh that's what I get for scrolling through the feed and replying before I get all the way to the bottom 😛 Commented on it :)

[m-allanson]

I think we can call this done. Thanks folks :)