Add `react-dom` and `react-router-dom` deps to the user's `package.json`

[infomiho]

Some users when installing deps e.g. react-hot-toast receive this error:

npm ERR! code ERESOLVE
npm ERR! ERESOLVE unable to resolve dependency tree
npm ERR! 
npm ERR! While resolving: rrtest@undefined
npm ERR! Found: [email protected]
npm ERR! node_modules/react
npm ERR!   react@"^18.2.0" from the root project
npm ERR!   peer react@">=16" from [email protected]
npm ERR!   node_modules/react-hot-toast
npm ERR!     react-hot-toast@"*" from the root project
npm ERR!   1 more (wasp)
npm ERR! 
npm ERR! Could not resolve dependency:
npm ERR! peer react@"^19.0.0" from [email protected]
npm ERR! node_modules/react-dom
npm ERR!   peer react-dom@">=16" from [email protected]
npm ERR!   node_modules/react-hot-toast
npm ERR!     react-hot-toast@"*" from the root project

Let's take a closer look:

• peer react@">=16" from [email protected]
  • says that react-hot-toast will be satisfied with any version of React above and including React 16.
  • We specified react@^18.2.0 in the user's package.json
  • so npm goes with that version.
  • All good ✅
• peer react-dom@">=16" from [email protected]
  • says that react-hot-toast will be satisfied with any version of React DOM above and including React DOM 16.
  • So, npm goes for the latest version since we don't specify react-dom in the user's package.json file.
  • Since React 19 came out, the latest means React DOM 19 which then tries to pull React 19.
  • This conflicts with our React 18 dep 🔴

A similar thing happened with React Router 7 being released, so we should also put react-router-dom dep in the user land package.json.

How to solve this

• I propose we add the react-dom and react-router-dom in the user's package.json in all the templates.
  • @vincanger updated Open Saas already
  • we need to update the starters templates
  • we need to update the basic template (requires new Wasp release)
• Also, let's ping any community template authors to do the same.
• We can add package.json validation rules in the next Wasp version to validate if users have these deps in their package.json for any users. that have an existing project.