Blitz: Error "Failed to execute 'btoa'" occur when setting multibyte string to session.create

[kyken]

What is the problem?

setting string containing multi-byte characters (e.g. Japanese) as a session.create argument will result in the following message: "Error Failed to execute 'btoa': The string to be encoded contains characters outside of the Latin1 range." error occurs.

Steps to Reproduce

1. run blitz new xxxxx
2. modify the session.create in the auth module to include a multi-byte string.
3. following error occurs when signup or login

 Error  Failed to execute 'btoa': The string to be encoded contains characters outside of the Latin1 range.

Versions

macOS Catalina | darwin-x64 | Node: v12.18.0

blitz: 0.25.0 (local)

  Package manager: yarn 
  System:
    OS: macOS 10.15.7
    CPU: (16) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 401.34 MB / 16.00 GB
    Shell: 5.7.1 - /bin/zsh
  Binaries:
    Node: 12.18.0 - ~/.nodebrew/current/bin/node
    Yarn: 1.22.10 - ~/.nodebrew/current/bin/yarn
    npm: 6.14.4 - ~/.nodebrew/current/bin/npm
    Watchman: 4.9.0 - /usr/local/bin/watchman
  npmPackages:
    @prisma/cli: 2.11.0 => 2.11.0 
    @prisma/client: 2.11.0 => 2.11.0 
    blitz: 0.25.0 => 0.25.0 
    react: 0.0.0-experimental-4ead6b530 => 0.0.0-experimental-4ead6b530 
    react-dom: 0.0.0-experimental-4ead6b530 => 0.0.0-experimental-4ead6b530 
    typescript: 4.0.5 => 4.0.5 

[jamiedavenport]

Thanks for raising this issue. I believe the issue is at the btoa call sites in https://github.com/blitz-js/blitz/blob/canary/packages/server/src/supertokens.ts

We're using the https://www.npmjs.com/package/b64-lite library so the docs should be useful.