[v2] [plugin-react-css-modules] Plugin/preset did not return an object

[madeleineostoja]

Description

Just upgraded to the v2 beta and all went well except for gatsby-plugin-react-css-modules, which is causing the new Babel setup to throw.

Basic error is:

here ./.cache/develop-static-entry.js
Module build failed (from ./node_modules/babel-loader/lib/index.js):
Error: [BABEL] /{...}/.cache/develop-static-entry.js: Plugin/Preset did not return an object.

Can provide a full stacktrace if it'd help, but it's pretty opaque. Only narrowed it down to react-css-modules through a process of elimination with my plugins.

Also noticed that it now requires a peer dep of react-css-modules, when I thought it was built on babel-plugin-react-css-modules?

Steps to reproduce

Include gatsby-plugin-react-css-modules in a Gatsby v2 build

Environment

  System:
    OS: macOS High Sierra 10.13.4
    CPU: x64 Intel(R) Core(TM) i5-7360U CPU @ 2.30GHz
    Shell: 5.5.1 - /usr/local/bin/zsh
  Binaries:
    Node: 9.0.0 - /usr/local/bin/node
    npm: 6.1.0 - /usr/local/bin/npm
  Browsers:
    Chrome: 67.0.3396.87
    Firefox: 60.0.1
    Safari: 11.1
  npmPackages:
    gatsby: ^2.0.0-beta.1 => 2.0.0-beta.1
    gatsby-image: ^2.0.0-beta.1 => 2.0.0-beta.1
    gatsby-plugin-favicon: ^2.1.1 => 2.1.1
    gatsby-plugin-manifest: ^2.0.2-beta.1 => 2.0.2-beta.1
    gatsby-plugin-netlify: ^2.0.0-beta.1 => 2.0.0-beta.1
    gatsby-plugin-nprogress: ^2.0.0-beta.1 => 2.0.0-beta.1
    gatsby-plugin-offline: ^2.0.0-beta.1 => 2.0.0-beta.1
    gatsby-plugin-react-css-modules: ^2.0.0-beta.1 => 2.0.0-beta.1
    gatsby-plugin-react-helmet: ^3.0.0-beta.1 => 3.0.0-beta.1
    gatsby-plugin-segment: ^1.0.2 => 1.0.2
    gatsby-plugin-sharp: ^2.0.0-beta.1 => 2.0.0-beta.1
    gatsby-plugin-svgr: ^1.0.0 => 1.0.1
    gatsby-source-prismic: ^2.0.0-alpha.1 => 2.0.0-alpha.1
    gatsby-transformer-sharp: ^2.1.1-beta.1 => 2.1.1-beta.1
  npmGlobalPackages:
    gatsby-cli: 2.0.0-beta.1

[madeleineostoja]

Changing this line https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby-plugin-react-css-modules/src/gatsby-node.js#L3 to 'babel-plugin-react-css-modules' fixes the error (and it trying to import react-css-modules rather than the babel plugin) but now my site isn't building properly anyway, so can't tell if react-css-modules is actually working.

This issue would suggest there are compat issues with Babel 7 regardless

[madeleineostoja]

Got my site building again, can confirm that ^ fixes the issue. Will submit a PR