Treat missing source map sources as non-fatal during SSR

Clear and concise description of the problem

Some NPM packages include source maps that reference sources which were not included as part of the package. For example, the Material Components reference the original Typescript sources in their source maps. When loading such a module for SSR, the missing sources cause Vite to throw an error.

A simple repro (after installing vite and @material/ripple):

const {createServer} = require('vite');

async function run() {
  const vite = await createServer();
  vite.ssrLoadModule('@material/ripple');
}

run();

results in:

node:internal/process/promises:218
          triggerUncaughtException(err, true /* fromPromise */);
          ^

[Error: ENOENT: no such file or directory, open '/home/repos/vite-issue/node_modules/@material/ripple/index.ts'] {
  errno: -2,
  code: 'ENOENT',
  syscall: 'open',
  path: '/home/repos/vite-issue/node_modules/@material/ripple/index.ts'
}

Suggested solution

Ignore missing sources in source maps.

Additional context

I ran into this issue when trying to set up SvelteKit with Material Components. I think it’s not uncommon for packages to not ship sources that are referenced in source maps so it would be nice for Vite to ignore such situations instead of having package authors fix their source maps.

[benmccann]

I hope it would continue to warn, but I agree this should not be an error. It is helpful to know when source maps are broken so that they can be fixed. Supabase fixed their sourcemaps as a result of this being surfaced https://github.com/supabase/supabase-js/issues/153

[bluwy]

This seems to be fixed now. Here’s a stackblitz link to reproduce it. The logs now show:

Sourcemap for "/home/projects/node-zfq2wn/node_modules/@material/ripple/index.js" points to missing source files
Sourcemap for "/home/projects/node-zfq2wn/node_modules/@material/ripple/util.js" points to missing source files
Sourcemap for "/home/projects/node-zfq2wn/node_modules/@material/ripple/adapter.js" points to missing source files
Sourcemap for "/home/projects/node-zfq2wn/node_modules/@material/ripple/constants.js" points to missing source files
Sourcemap for "/home/projects/node-zfq2wn/node_modules/@material/ripple/types.js" points to missing source files
Sourcemap for "/home/projects/node-zfq2wn/node_modules/@material/ripple/foundation.js" points to missing source files
Sourcemap for "/home/projects/node-zfq2wn/node_modules/@material/ripple/component.js" points to missing source files
Sourcemap for "/home/projects/node-zfq2wn/node_modules/@material/base/foundation.js" points to missing source files
Sourcemap for "/home/projects/node-zfq2wn/node_modules/@material/dom/events.js" points to missing source files
Sourcemap for "/home/projects/node-zfq2wn/node_modules/@material/dom/ponyfill.js" points to missing source files
Sourcemap for "/home/projects/node-zfq2wn/node_modules/@material/base/component.js" points to missing source files

without crashing.