storybook: utility.assert is not a function

Funny you mention that @csantos1113 https://github.com/storybookjs/storybook/pull/19341#issuecomment-1267980712

So this issue will be fixed in 7.0.

@shilman / @ndelangen should we patch this back to 6.5? (https://github.com/storybookjs/storybook/pull/19358)

I ended up disabling the @storybook/addon-docs to get rid of the error. This can be done by replacing the '@storybook/addon-essentials' in the main config with the following:

   ...
    {
      name: '@storybook/addon-essentials',
      options: {
        docs: false,
      },
    },

This isn’t a fix or workaround. It’s just a way to get rid of the error by disabling the add-on as described in docs.

alternatively, you can add a fallback to the webpackFinal config function and provide a polyfill.

In this case, you can add the commonjs-assert package.

yarn add --dev commonjs-assert

Then add a property to the webpack final config in main.js

const path = require('path');
const toPath = (filePath) => path.join(process.cwd(), filePath);
...
module.exports = {
 webpackFinal: async (config) => ({
    ...config,
    resolve: {
      ...config.resolve,
     // can likely be removed in storybook > 6.4 see - https://github.com/storybookjs/storybook/issues/17458
     fallback: {
       ...config.resolve.fallback,
      'assert': toPath('commonjs-assert')
     }
    },
 })
}

In any case going to close this as it is fixed in 7.0. Please try upgrading if you are still seeing problems!