Rebuilds fail when app is using WebpackBundleAnalyzer & probably others

[bendemboski]

Reproduction

$ npx ember-cli new test-app
$ cd test-app/
$ yarn add --dev @embroider/core @embroider/compat @embroider/webpack webpack webpack-bundle-analyzer

edit ember-cli-build.js to look like:

'use strict';

const EmberApp = require('ember-cli/lib/broccoli/ember-app');
const { BundleAnalyzerPlugin } = require('webpack-bundle-analyzer');

module.exports = function (defaults) {
  const app = new EmberApp(defaults, {
    // Add options here
  });

  const { Webpack } = require('@embroider/webpack');
  return require('@embroider/compat').compatBuild(app, Webpack, {
    packagerOptions: {
      webpackConfig: {
        plugins: [new BundleAnalyzerPlugin()],
      },
    },
  });
};

run ember serve, then edit a file to cause a rebuild.

Result

The rebuild fails with this error:

ERROR Summary:

  - broccoliBuilderErrorStack: TypeError: Converting circular structure to JSON
    --> starting at object with constructor 'Compiler'
    --- property 'root' closes the circle
    at JSON.stringify (<anonymous>)
    at stringify (/private/tmp/test-app/node_modules/fs-extra/node_modules/jsonfile/utils.js:3:20)
    at outputJsonSync (/private/tmp/test-app/node_modules/fs-extra/lib/json/output-json-sync.js:7:15)
    at AppBuilder.addResolverConfig (/private/tmp/test-app/node_modules/@embroider/core/src/app.js:966:35)
    at AppBuilder.build (/private/tmp/test-app/node_modules/@embroider/core/src/app.js:887:10)
    at async WaitForTrees.buildHook (/private/tmp/test-app/node_modules/@embroider/core/src/build-stage.js:33:13)
  - code: [undefined]
  - codeFrame: Converting circular structure to JSON
    --> starting at object with constructor 'Compiler'
    --- property 'root' closes the circle
  - errorMessage: Converting circular structure to JSON
    --> starting at object with constructor 'Compiler'
    --- property 'root' closes the circle
        at WaitForTrees (@embroider/compat/app)
-~- created here: -~-
    at new Plugin (/private/tmp/test-app/node_modules/@embroider/core/node_modules/broccoli-plugin/dist/index.js:47:36)
    at new WaitForTrees (/private/tmp/test-app/node_modules/@embroider/core/src/wait-for-trees.js:30:9)
    at CompatApp.get tree (/private/tmp/test-app/node_modules/@embroider/core/src/build-stage.js:25:16)
    at CompatApp.<anonymous> (/private/tmp/test-app/node_modules/typescript-memoize/dist/memoize-decorator.js:132:52)
    at new PackagerRunner (/private/tmp/test-app/node_modules/@embroider/core/src/to-broccoli-plugin.js:11:26)
    at Object.defaultPipeline (/private/tmp/test-app/node_modules/@embroider/compat/src/default-pipeline.js:50:12)
    at module.exports (/private/tmp/test-app/ember-cli-build.js:12:39)
    at Builder.readBuildFile (/private/tmp/test-app/node_modules/ember-cli/lib/models/builder.js:48:20)
    at async Builder.setupBroccoliBuilder (/private/tmp/test-app/node_modules/ember-cli/lib/models/builder.js:68:17)
    at async Builder.ensureBroccoliBuilder (/private/tmp/test-app/node_modules/ember-cli/lib/models/builder.js:56:7)

Analysis

When the webpack-bundle-analyzer plugin's apply() is called, it caches a copy of the compiler object on itself. That object contains a reference back to the plugin, creating a circular reference. When embroider tries to write out the resolver config on a rebuild, it fails because the config options now contain a circular reference and are not JSON stringifiable.

In general, I think it looks like the webpack config is not guaranteed to be JSON stringifiable, so trying to stringify the whole configuration isn't a safe thing to do. Perhaps CompatAppAdapter.resolverConfig() should not be returning its entire CompatResolverOptions, but instead filtering them down to only the fields needed to implement the module resolver options? Or addResolverConfig() should prune down the object it receives to just the set of fields that match the interface?

[chancancode]

Same issue with extraPublicTrees, it does seem like addResolverConfig is trying to serialize too much

[chancancode]

This appears to be the subset that it should have picked out

[achambers]

Should be fixed by: #1481