Plugin Alias v3 throws error

[mattpilott]

• Rollup Plugin Name: Alias
• Rollup Plugin Version: 3.0.1
• Rollup Version: 1.31.0
• Operating System (or Browser): macOS 10.15.3
• Node Version: 13.8.0

How Do We Reproduce?

https://repl.it/repls/WatchfulUnsightlyStruct

Expected Behavior

Expect to compile as per v2.2.0

Actual Behavior

Throws mysterious error (plugin alias) TypeError: Cannot read property 'input' of undefined

Thanks!

[bennypowers]

I'm able to avoid this error with:

plugins: [
    customResolver,
    alias({ entries: importAliases, customResolver })
]

As a user, I may have expected alias to cover all cases of resolve

[mattpilott]

@bennypowers It seems that your workaround is good, will shout if i run into anything.

Thanks!

[pkit]

It's not a workaround, because it just disables aliasing in a general case.
Alias should come before node-resolve.
Example in README changed to one that actually woks:

// rollup.config.js
import alias from '@rollup/plugin-alias';
import resolve from '@rollup/plugin-node-resolve';

const customResolver = resolve({
  extensions: ['.mjs', '.js', '.jsx', '.json', '.sass', '.scss']
});
const projectRootDir = path.resolve(__dirname);

const config = {
  // ...
  plugins: [
    alias({
      entries: [
        {
          find: 'src',
          replacement: path.resolve(projectRootDir, 'src')
          // OR place `customResolver` here. See explanation below.
        }
      ],
      customResolver
    }),
    resolve()
  ]
};
customResolver.buildStart(config);
export default config

[shellscape]

@pkit thanks for confirming. We're going to close citing that comment. If the example in the readme doesn't work for anyone else, please drop a comment here.

[vladshcherbin]

Example from docs doesn't work. Workaround from #203 (comment) works, even if @rollup/plugin-node-resolve is placed after alias:

const nodeResolve = resolve()

plugins: [
  alias({
    entries: { ... },
    customResolver: nodeResolve
  }),
  nodeResolve
]

However, it feels more like a hack than a solution.

[pkit]

Workaround doesn't work for any node_modules alias.
I.e. my case: use 'react-dom': 'react-dom/profiling' alias
With or without alias the output is the same if placed after node-resolve

[shellscape]

@vladshcherbin previous commenter indicates that's not so. unless someone can pinpoint why it's not working a positive assertion that it does work is going to take precedent.

[vladshcherbin]

@pkit didn't test it with node_modules alias, only local ones.

Anyway, this issue shouldn't be closed as it's clearly not working for many users following example from current docs. This is the reason we all came to this issue 😉

[shellscape]

I'll reopen if someone can provide an updated reproduction. The repro provided on the original post doesn't run.

[pkit]

@shellscape it's easy to pinpoint why it's not working: when placed after node-resolve alias is working on resolved paths and not on original. i.e. react-dom?commonjs-proxy
But I'm nor sure I need to tell it to you. After all I'm not the author of rollup

[shellscape]

@pkit I'm not the author of Rollup or the alias plugin either. I'm a contributor and team member for maintaining the plugins. Because of the volume of issues we get here we just need reproductions so we don't spend time on trying to recreate the issues folks report.

[pkit]

@shellscape cool, anyway. It seems like combination of node-resolve and commonjs makes it not resolvable in a generic case.
I suppose adding more hacks to alias can help.
here:

plugins/packages/alias/src/index.ts

Line 90 in ee5be6a

typeof options.customResolver!.resolveId === 'function'

 else if (
        typeof options.customResolver === 'object' &&
        typeof options.customResolver!.resolveId === 'function'
      )

[vladshcherbin]

@shellscape here's reproduction - https://github.com/vladshcherbin/rollup-alias-error, latest alias version (3.1.0), docs example. Run with yarn build (or npm)

Screenshot