Windows clientModule returning null

[bskimball]

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the bug has not already been reported

Fastify version

3.29.0

Plugin version

3.0.0-beta.21

Node.js version

16.15.1

Operating system

Windows

Operating system version (i.e. 20.04, 11.3, 10)

10

Description

When running vue-stream example on Windows we receive an error:

TypeError: Cannot read properties of null (reading 'replace')

this comes from the following line in node_modules/fastify-vite/mode/development.js

const modulePath = resolve(config.vite.root, config.clientModule.replace(/^\/+/, ''))

it looks like the root of the client is returning null. On linux this same app works fine.

In order to fix this on Windows I changed the root in vite config to a relative path (i.e. "./client"). And in package.json, I change the "build:server" file to "./index.js"

After changing to relative urls, when I start the server I get

Error [ERR_UNSUPPORTED_ESM_URL_SCHEME]: Only URLs with a scheme in: file, data are supported by the default ESM loader. On Windows, absolute paths must be valid file:// URLs. Received protocol 'c:'

It may be related to this issue nodejs/node#37845

Steps to Reproduce

Copy vue-stream example to a windows machine and try to use

Expected Behavior

No response

[bskimball]

What I've done is replace the vite config root with a relative url.
Then I changed the start script to "./server.js" instead of "server.js"

Looks like the error is thrown in the loadClient function in mode/production.js.

production.js line 53

const serverBundle = await import(resolve(config.bundle.dir, serverFile))

of course if I remove the dynamic import the app says it started but I get a 404 error when navigating to the home page

[bskimball]

I have changed line 53 to use the file path for the dynamic import:

const serverBundle = await import(fileUrl(resolve(config.bundle.dir, serverFile)));

function fileUrl(str) {
  if (typeof str !== 'string') {
    throw new Error('Expected a string');
  }

  var pathName = resolve(str).replace(/\\/g, '/');

  // Windows drive letter must be prefixed with a slash
  if (pathName[0] !== '/') {
    pathName = '/' + pathName;
  }

  return encodeURI('file://' + pathName);
};

This obviously needs to be cleaned up and tested but this is working on Windows.

[bskimball]

I created PR #85 in order to address these issues.